Program
December 20(Wed)Session 1: 9:00 – 10:40
Chair: Jae-Hyeung Park, Inha University
Key20a-1
9:00
|
9:50

Research and development of holographic optical element for threedimensional display and microscopy
Nam Kim, Munkh-Uchral Erdenebat, Ki-Chul Kwon, and Young-Tae Lim
Chungbuk National University…………01

Inv20a-1
9:50
|
10:15

Three dimensional structure of subdiffraction limit optical patterns

Inv20a-2
10:15
|
10:40

Yusuke Ogura and Jun Tanida
Osaka University…………02

Research activities in KETI
Hoonjong Kang
Korea Electronics Technology Institute…………03Session 2: 11:00 – 12:15
Chair: Naoya Tate, Kyushu University
Inv20a-3
11:00
|
11:25

Ghost imaging for single photon counting
Yasuhiro Mizutani1,2, Hiroki Taguchi1, Yasuhiro Takaya1
1Osaka Univesity,
2JST/ERATO MINOSHIMA Intelligent Optical Synthesizer Project…………04

Inv20a-4
11:25
|
11:50

Fast calculation of wide viewing angle depth-map computer-generated
hologram
Hwi Kim, Sungjae Park, and Jonghyun Lee
Korea University…………05

Inv20a-5
11:50
|
12:15

Compound-eye imaging for forensics
Yoshinori Akao
National Research Institute of Police Science

Lunch Time…………06

Session 3: 13:30 – 14:45
Chair: Hwi Kim, Korea University
Inv20p-1
13:30
|
13:55

3D display making light field inside volume
Joonku Hahn
Kyungpook National University…………07

Inv20p-2
13:55
|
14:20

Nanoscale character extraction for nano-optical metric system
Naoya Tate
Kyushu University

Inv20p-3
14:20
|
14:45

Reflective-type reconfigurable digital hologram panel using Ge2Sb2Te5
phase change material
Seung-Yeol Lee
Kyungpook National University…………09…………08

Session 4: 15:05 – 16:20
Chair: Yusuke Ogura, Osaka University
Inv20p-4
15:05
|
15:30

Unstained tumor detection in digestive organs based on autofluorescence
spectroscopy
Hidenobu Arimoto1, Keiichiro Kagawa2, Yoji Sanomura3, Shigeto Yoshida4,and Shinji Tanaka3
1National Institute of Advanced Industrial Science and Technology,
2Shizuoka University, 3Hiroshima University Hospital, 4JR Hiroshima Hospital….…10aInv20p-5
15:30
|
15:55
Inv20p-6
15:55
|
16:20

Recent progress on 3D target tracking using optical scanning holography
Taegeun Kim
Sejong University…………11

Multi-frequency swept en-face optical coherence microscopy withsupercontinuum comb for in-vivo measurement of inner ear
Samuel Choi1,4, Fumiaki Nin2,4, Takeru Ota2,4, Keita Sato3, Takamasa Suzuki3and Hiroshi Hibino2,4
1,2,3,4Niigata University…………13

Poster Session: 16:40 – 18:00
p20-1

Polarization Color Display Using Index Matching
Toshiki Matsuzaki, Huangyi Qin and Kenji Harada
Kitami Institute of Technology

p20-2…………14

Polarization color optimization of birefringent material
Huangyi Qin, Toshiki Matsuzaki and Kenji Harada
Kitami Institute of Technology…………15

p20-3

Object recognition through a multi-mode fiber based on machinelearning
Ryosuke Takagi, Ryoichi Horisaki and Jun Tanida
Osaka University…………16

p20-4

Spectral imaging based on single pixel camera
Ryo Sato, Kazuki Ota and Yoshio Hayasaki
Utsunomiya University…………17

p20-5

Aerial Volumetric Display with Pyramid Structured LED Lattice and
AIRR
Kazuki Shimose1 and Hirotsugu Yamamoto1,2
1Utsunomiya University, 2JST.ACCEL…………18p20-6Forming the aerial 3D image of your back in front of you with using
AIRR
Ryosuke Kujime1,2 and Hirotsugu Yamamoto1,2
1Utsunomiya University, 2JST.ACCEL…………19p20-7

Multi-layered head-mounted display for occlusion and accommodation
effects
Mugoen Kim, Daerak Heo, and Joonku Hahn
Kyungpook National University…………20p20-8Depth resolution enhancement of computational reconstruction of
integral imaging with considering continuously non-uniform shifting pixel
Byungwoo Cho1, Hui Yun1, Kotaro Inoue1, Ki-Ok Cho1, Kyungtae Park1,2,
Jungsik Koo2, Jiyong Park2, Cheol-su Kim3, Min-Chul Lee4 and Myungjin Cho1
1Hankyong National University, 2Gumi Electronics & Information Technology Research Institute,
3Gyeongju University, 4Kyushu Institute of Technology…………21

p20-9Pixel Blink Rate based Depth Estimation Technique in Integral Imaging
with Markov Random Field Optimization
Kotaro Inoue1, Byeongwoo Cho1, Hui Yoon1, Ki-Ok Cho1, Kyungtae Park1,2,
Jungsik Koo2, Jiyong Park2, Cheol-Su Kim3, Min-Chul Lee4, Myungjin Cho1
1Hankyong National University, 2Gumi Electronics & Information Technology Research Institute,
3Gyeongju University, 4Kyushu Institute of Technology…………22

p20-10Three-dimensional image sensing and visualization to enhance 3D
resolution of integral imaging
Hui Yun1, Byeongwoo Cho1, Ki-Ok Cho1, Kyungtae Park1,2, Kotaro Inoue1,
Jungsik Koo2, Jiyong Park2, Cheol-Su Kim3, MinChul Lee4, Myungjin Cho1
1Hankyong National University, 2Gumi Electronics & Information Technology Research Institute,
3Gyeongju University, 4Kyushu Institute of Technology…………23

p20-11

Multiple projection 3D display on diffusive fog screen
Jiman Yu, Minwoo Jung, Daerak Heo, Geunseop Choi, and Joonku Hahn
Kyungpook National University…………24

p20-12Complex object wave extraction using time-multiplexing in off-axis
digital holography
Erkhembaatar Dashdavaa, Munkh-Uchral Erdenebat, Nyamsuren Darkhanbaatar,
Anar Khuderchuluun, and Nam Kim
Chungbuk National University…………25

p20-13

Fast calculation method for full-color holographic system of real existing
objects
Yu Zhao1, Ki-Chul Kwon1, Seok-Hee Jeon2, Sang-Keun Gil3, Nam Kim1
1Chungbuk National University, 2Incheon National University, 3Suwon University…………26

p20-14

A refractive index sensor based on an extraordinary optical transmission
in a floated metal nano-slit array
Hee-Dong Jeong1, Yong-Sang Ryu2 and Seung-Yeol Lee1
1Kyungpook National University, 2Korea Institute of Science and Technology…………27

p20-15

Analysis on random plasmonic nanopillar structure using Bruggeman
effective medium theory
Youngkyu Bae1, Yong-Sang Ryu2, and Seung-Yeol Lee1
1Kyungpook National University, 2Korea Institute of Science and Technology…………28p20-16Fabrication of camera lens using photopolymer
Seo-Yeon Park, Jae-Min Lee, Chang-Won Shin, Hui-Ying Wu, and Nam Kim
Chungbuk National University…………29p20-17

Universal light engine with three digital micromirror devices
Kwangsoo Kim, Geunseop Choi, Daerak Heo, and Joonku Hahn
Kyungpook National University…………30p20-18

Spherical light field display
Daerak Heo, Mugeon Kim and Joonku Hahn
Kyungpook National University

p20-19…………31Time-sequential super multi-view display
Sungjin Lim, Geunseop Choi, Mugeon Kim, Kwangsoo Kim and Joonku Hahn
Kyungpook National University…………32

p20-20Cylindrical light field display
Geunseop Choi1, Hosung Jeon1, Kwangsoo Kim1, Hwi Kim2 and Joonku Hahn1
1Kyungpook National University, 2Korea University…………33

p20-21

Orthographic projection based holography with low density modelingpoint cloud
Yan-Ling Piao1, Alam MD Shahinur1, Jong-Rae Jeong2 and Nam Kim1
1Chungbuk National University, 2Suwon Science College…………34

p20-22Analysis of 360-degree Non-Mechanical
Holographic Display system
Soobin Kim and Hwi Kim
Korea University

Table

Top

Electronic…………35p20-23

Geometrical optical modeling and diffraction efficiency analysis ofdiffractive augmented reality system
JungBeom Choi, JongHa Park, SooBin Kim, and Hwi Kim
Korea University…………36

p20-24

Fast Calculation Method of High-Definition Computer-Generated
Hologram
Sungjae Park, Jonghyun Lee and Hwi Kim
Korea University…………37

p20-25

Analysis of Moiré Deflectometry in Display System using Talbot EffectJunghwan Park and Hwi Kim
Korea University…………38p20-26

Localization Method of Depth-map Computer Generated Hologram for
Fast Calculation
JongHa Park, JiSung Yoon, SungJae Park, JongHyun Lee and Hwi Kim
Korea University…………39p20-27Comparison of LED and LD as a light source for near-eye holographic
display
Dukho Lee, Gang Li, Byounghyo Lee and Byoungho Lee
Seoul National University…………40p20-28

Augmented-Reality Display for Supporting Ametropia using Maxwellianview and Edge Enhancement
Byounghyo Lee1, Seungjae Lee1, Dukho Lee1, Hee-Jin Choi2 and Byoungho Lee1
1Seoul National University, 2Sejong University…………42

p20-29Apparatus for measuring large field of view embossed hologram
Sunggyun Ahn, Geunseop Choi, Mugeon Kim and Joonku Hahn
Kyungpook National University…………44

p20-30Time division multiplexed holographic display using electronic beamsteering method
Hyun-Eui Kim, Minsik Park and Jinwoong Kim
Electronics and Telecommunications Research Institute (ETRI)…………45

p20-31

Improving the image quality of a digital holographic display system by
estimating a virtual spatial light modulator plane
Yongjun Lim, Keehoon Hong, Minsik Park, Jinwoong Kim
Electronics and Telecommunications Research Institute (ETRI)…………46

p20-32

3D smart table display
Sang-Hyeok Mun, Muhan Choi
Kyungpook National University

p20-33…………47

Tunable Graphene Metasurface Application
Yong-Hoon Lee, Sang-Hyeok Mun, Inbo Kim and Muhan Choi
Kyungpook National University…………48p20-34Compressive holographic optical sectioning
Junkyu Yim, Seungwhi Yoo, and Sung-Wook Min
Kyung Hee University…………49p20-35

Digital Holographic Tabletop display with vertical parallax by pupil
tracking
Jaehan Kim, Hyongon Choo, Minsik Park and Jinwoong Kim
Electronics and Telecommunications Research Institute (ETRI)…………50p20-36

Optical design of table-top light field display
Kwangsoo Kim, Daerak Heo, and Joonku Hahn
Kyungpook National University…………51

p20-37

Augmented Reality Near-eye Light-field 3D Display Using Retroreflector
Hyeongkyu Do, Young Min Kim, Hyunsik Sung, Ki-Hong Choi,
Sungwon Choi and Sung-Wook Min
Kyung Hee University…………52

p20-38

Improvement in Phase Pattern Design for Holographic Shack-Hartmann
Wavefront Sensor with High Sensitivity
Yusuke Saita and Takanori Nomura
Wakayama University…………53

p20-39GPU acceleration of hologram calculation using an orthographic raysampling plane
Shunsuke Igarashi1, Tomoya Nakamura1,2, Kyoji Matsushima3,
and Masahiro Yamaguchi1
1Tokyo Institute of Technology,
2Japan Science and Technology Agency, 3Kansai University…………54

p20-40Angular spectrum convolution based occlusion processing in computer
generated hologramMehdi Askari and Jae-Hyeung Park
Inha University…………56

p20-41

Speckle reduction using angular spectrum interleaving for triangularmesh based computer generated hologram
Seok-Beom Ko and Jae-Hyeung Park
Inha University…………57

p20-42

See-through Maxwellian display using waveguide and multiplexing
holographic optical element
Seong-Bok Kim, Jae-Hyeung Park
Inha University…………58p20-43

Acceleration of fully analytic mesh based computer generated hologramusing foveated rendering techniqueYeon-Gyeong Ju and Jae-Hyeung Park
Inha University…………59p20-44

An analysis of light field type head-up displays for vehicles
KwangSoo Shin, Jae-Hyeung Park
Inha University…………60December 21(Thu)
Session 5: 9:00 – 10:40
Chair: Yoshio Hayasaki, Utsnomiya University
Key21a-1
9:00
|
9:50
Inv21a-1
9:50
|
10:15
Inv21a-2
10:15
|
10:40

Full-parallax light-field and holographic displays
Masahiro Yamaguchi
Tokyo Institute of Technology…………61

Table-top Holographic Display with Full Parallax
Minsik Park, Yongjun Lim, Keehoon Hong, Eun-Young Chang,
Hayan Kim, Jaehan Kim and Jinwoong Kim
Electronics and Telecommunications Research Institute (ETRI)…………62
Enlargement of viewing zone of holographic 3D display using a parabolic
mirrorYusuke Sando3, Kazuo Satoh3, Takahiro Kitagawa3, Makoto Kawamura3,
Daisuke Barada1,2 and Toyohiko Yatagai1
3Osaka Research Institute of Industrial Science and Technology,
1,2Utsunomiya University…………63Session 6: 11:00 – 12:15
Chair: Kwang-Hoon Lee, Korea Photonics Technology Institute (KOPTI)
Inv21a-3
11:00
|
11:25
Inv21a-4
11:25
|
11:50
Inv21a-5
11:50
|
12:15

Formation of dynamic viewing zone in autostereoscopic 3D display
Sung-Kyu Kim, Ky-Hyuk Yoon, and Min-Koo Kang
Korea Institute of Science and Technology…………64

Aerial Multi-Modal Information Display
Hirotsugu Yamamoto1,2, Tomoyuki Okamoto1, Shusei Ito1 and Ryosuke Kujime1,2
1Utsunomiya University, 2JST. ACCEL…………66
Metasurfaces for holograms
Byoungho Lee and Gun-Yeal Lee
Seoul National University

Lunch Time…………67

Session 7: 13:30 – 14:45
Chair: Hee-Jin Choi, Sejong University
Inv21p-1
13:30
|
13:55
Inv21p-2
13:55
|
14:20
Inv21p-3
14:20
|
14:45

Common-path incoherent digital holography
Osamu Matoba1, Xiangyu Quan1 and Yasuhiro Awatsuji2
1Kobe University, 2Kyoto Institute of Technology…………68

Photonic meta-devices based on optical path control
Muhan Choi, Inbo Kim, Jinhang Cho, and Sang-Hyeok Mun
Kyungpook National University…………69Multidimensional imaging with phase-shifting interferometry
Tatsuki Tahara1,2, Reo Otani3, Yasuhiko Arai1 and Yasuhiro Takaki4
1Kansai University, 2Japan Science and Technology Agency,
3SIGMAKOKI CO. LTD, 4Tokyo University of Agriculture and Technology…………70

Session 8: 15:05 – 16:20
Chair: Minsik Park, Electronics and Telecommunications Research Institute (ETRI)
Inv21p-4
15:05
|
15:30

Quantitative verification for whether LF display system can serve
accommodative function to the observer
Kwang-Hoon Lee and Seon Kyu Yoon
Korea Photonics Technology Institute…………71

Inv21p-5
15:30
|
15:55

How to control polarization color
Kenji Harada, Toshiki Matsuzaki and Huangyi Qin
Kitami Institute of Technology

Inv21p-6
15:55
|
16:20

Research on effects of physiological depth cues on the visual discomfort
of augmented reality displays
Hee-Jin Choi, Hanul Lee, Minyoung Park, and Jaehee Seo
Sejong University…………73…………72

December 22(Fri)
Session 9: 9:00 – 10:40
Chair: Hirotsugu Yamamoto, Utsunomiya University
Inv22a-1
9:00
|
9:25
Inv22a-2
9:25
|
9:50

Volumetric Bubble Display
Yoshio Hayasaki and Kota Kumagai
Utsunomiya University…………74

Accommodative optical-see-through near-to-eye displays using
waveguide and holographic optical elements
Jae-Hyeung Park, Seong-Bok Kim, Seok-Beom Ko, Kwang-Soo Shin,
Yeon-Gyeong Ju, Dae-Yeol Park, and Askari Mehdi
Inha Univesity…………75

Inv22a-3
9:50
|
10:15

Incoherent holography without depth of field
Takanori Nomura1, Takuya Matsuda2
1,2Wakayama University

Inv22a-4
10:15
|
10:40

Recent researches for two type 3D screens: Reflection-type andTransmission-typeSung-Wook Min and Hyunsik Sung
Kyung Hee University…………77…………76

Key20a-1

N. KimResearch and development of holographic optical element forthree-dimensional display and microscopy
Nam Kim*, Munkh-Uchral Erdenebat, Ki-Chul Kwon, and Young-Tae Lim
School of Information and Communication Engineering, Chungbuk National University,
Cheongju, Chungbuk 28644, South Korea
Tel.:82-43-261-2482, *E-mail: namkim@chungbuk.ac.kr
OCIS codes: (090.2890) Holographic optical elements; (110.3010) Image reconstruction techniques; (180.6900)
Three-dimensional microscopy

The holographic optical element (HOE) can be applied in various fields of three-dimensional (3D) applications
such that the light field camera, head-mounted display (HMD), holographic printer, hologram memory and so on.
Due to the advantageous function of HOE that it can be applied as a lens/lens array and mirror etc., according tohigh diffraction efficiency and narrow-band frequency characteristics, the design of optical systems can be lighter,thinner and smaller. For example, the HOE film can be applied as the in and out-coupling elements in the
waveguide-type 3D HMD, the HMD is getting lighter, so it can be wearable for a long time, and applied to a
glass-type display with an AR function. When the optical properties of microlens array are recorded onto the HOE
film, it can be used in the light field camera and microscopy based on integral imaging technique. By using the
spatial or rotational multiplexing methods, multiple microlens array’s properties can be recorded, and single HOE
film images the different 3D perspectives. Also, the HOE film is applied in the typical camera as a main lensinstead of a huge and heavy glass lens.
In this report, we discussed the recent research and development of the HOE for the applications of 3D imaging
field such as 3D display and microscopy. Figure 1 shows the example of full-color HOE for HMD and rotationallymultiplexed HOE-MLA for integral imaging microscopy. Experimental results presented that the use of HOE has
several advantages such as miniaturization of optical devices.

Fig. 1. The examples for applications of HOE in the optical imaging systems: (a) full-color HOE for HMD,
and (b) a visualization of rotationally multiplexed HOE micro lens array for integral imaging microscopy.
Acknowledgment
This research was supported by the Government of Korea, under the ITRC (Information Technology ResearchCenter) support program (IITP-2017-2015-0-00448) supervised by the IITP (Institute for Information &communications Technology Promotion), and supported by the National Research Foundation of Korea (NRF)
grant funded by the Government of Korea (No. NRF-2017R1A2B4012096).
References
1. M.-L. Piao and N. Kim, Appl. Opt., 53(10), 2180 (2014).
2. M.-L. Piao, H.-Y. Wu, and N. Kim, Digital Holography and 3-D Imaging 2016, JW4A.50 (2016).

DHIP 20171

Inv20a-1

Y. Ogura

Three dimensional structure of subdiffraction limit optical patterns
Yusuke Ogura and Jun Tanida
Graduate School of Information Science and Technology, Osaka University, Suita, Osaka 565-0871, Japan
Tel.:81-6-6879-7849, E-mail: ogura@ist.osaka-u.ac.jp
OCIS codes: (090.1760) Computer holography; (050.1940) Diffraction; (070.6120) Spatial light modulators
Diffractive optical elements (DOEs) have high design flexibility, and they can provide a variety of functions as asingle device. However, these functions are based on diffraction, and therefore, the behavior of the DOEs isgoverned by the diffraction limit. To enhance the functionality under the diffraction limit, we have demonstrated
DOEs that generate an array of spots smaller than a single diffraction-limited spot [1,2]. We refer such fine patterns
as subdiffraction limit optical patterns. This strategy is effective to realize fine patterns using propagating light; thus
distinctive properties such as spatial parallelism, remote accessibility, and multiplexing capability are utilizablestraightforwardly in optical application systems.
In this paper, we focus on generation of subdiffraction limit light sheets. A light sheet is, for example, used in lightsheet fluorescence microscopy (LSFM), which enables three-dimensional imaging of a sample with low damage
and high contrast. The resolution along the optical axis of this type of microscopy depends on the thickness of alight sheet used as illumination, so that generation of a thin light sheet is an important factor for the axial resolution.
Furthermore, patterned light sheets are realized by a DOE, which is useful to provide a new function in LSFM.
To use a subdiffraction limit light sheet in LSFM, it is important to know the three-dimensional structure. For the
purpose, we analyzed intensity distributions of subdiffraction limit light sheets at many planes, and experimentallyobserved them. As an example of the analyses, Fig. 1 shows the intensity distribution on a plane parallel to theoptical axis (z axis) and the direction of the sheet's width (x axis) for DOEs generating a single and threesubdiffraction limit light sheets. The result shows that the z-direction length of the central light sheet of the threelight sheets is longer than that of a single light sheet. In summary, this kind of investigation is effective to understandthe diffraction characteristics of subdiffaraction limit optical patterns. It is demonstrated that subdiffaraction limit
optical patterns offer distinctive features and they are valuable in microscopy applications.

Fig. 1. The intensity distribution on the xz-plane when generating (a) a single subdiffraction limit light sheet
and (b) three subdiffraction limit light sheets.
Acknowledgment
This work was supported by Research Foundation for Opto-Science and Technology and JSPS KAKENHI Grant
Number 17H02084.
References
1. Y. Ogura, M. Aino, and J. Tanida, Opt. Express, 22(21), 25196 (2014).
2. Y. Ogura, M. Aino, and J. Tanida, Appl. Opt., 55(23), 6371 (2016).

DHIP 20172

Inv20a-2

H. Kang

Research activities in KETI
Hoonjong Kang
Korea Electronics Technology Institute, 11, World Cup buk-ro 54-gil, Mapo-gu, Seoul, South Korea

DHIP 20173

Inv20a-3

Y. Mizutani

Ghost imaging for single photon counting
Yasuhiro Mizutani1,2, Hiroki Taguchi1, Yasuhiro Takaya1
Dept. of Mechanical Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 5605-0871, Japan
Tel.:82-6-6879-7319, E-mail: mizutani@mech.eng.osaka-u.ac.jp
2
JST/ERATO MINOSHIMA Intelligent Optical Synthesizer Project, Japan

1

OCIS codes: (110.1758) Computational imaging; (110.2970) Image detection systems; (030.5260) Photon
counting

We propose a novel single pixel imaging based on the Ghost Imaging (GI) in a photon limited imaging. In thispaper, in order to obtain image using few photons, the First Photon-detection Time (FPT) is applied to the GI. The
proposed signal detection method is able to obtain a signal with only 1 photon. The FPT has variations that are
due to a shot noise. Using a correlation, effect of the noise on images is removed. As a result, the GI with FPT(FPGI) was able to obtain high quality image than a conventional imaging method using same photon numbers.
A basic configuration of the FPGI is shown in fig. 1 (a). Random-patterned excitation lights (λ=560nm) from a
DMD projector (Texas Instruments, DLP Lightcrafter) are projected on a fluorescent sample thorough an
objective lens (OLYMPUS, x50, N.A. 0.8). Then fluorescence signals thorough a band pass filter for cutting theexcitation light are detected by a photo-multiplier tube (PMT, Hamamatsu: H10682-110). Finally, by analyzing acorrelation between the illuminated patterns and the detected signals, a fluorescence image can be detected as a
2D distribution of a correlation efficient. For realizing the ghost image with more high sensitivity, we have usedarrival times after excitation as fluorescent signals by using photon counting technique as shown in fig. 1 (b). The
time depending on the light power, the ghost image using correlation between the patterns and the time is possible
to detect a fluorescent image with weak light intensity.
I3(x,y)I2(x,y)I1(x,y)(a)
DMD projector
LED
DMD(560nm)ΔIi(x,y)aperture

T3=1/λ3
T2=1/λ2
T1=1/λ1
counts

ND ﬁlter
objec3ve lens
(×50, N.A.0.8)
sampleillumina3on 3me

PMTband pass ﬁlter(600-690nm)

correla3onG(x, y)= ⊗λi⊗Ii (x, y)Δλiphotoncounter(b)
illumination :countsper unit time

signals :conventional
B1
T1

B2
T2

B3

proposed

T3

Fig. 1. Experimental setup of first photon detection ghost imaging (FPGI) and results. (a) optical configuration, (b) datadetection analogy and (c) qualities of fluorescent images using sub 100 photons.

Figure 1(c) shows experimental results of fluorecent microsphere (φ=8µm) images by using the FPGI. To
evaluate the images quantitatively, we used the contrast-to-noise ratio (CNR) like visivility(2. As the photon
numbers beyond 50 numbers, the image can be detected by using FPGI. Therefore, it has been found that the
proposed method is well suited for imaging when photon number is limited.
References
1. T. B. Pittman, Y. H. Shih, D. V. Strekalov, and A. V. Sergienko, Phys. Rev. A 52, R3429 (1995).
2. K. W. C. Chan, M. N. O’Sullivian and R. W. Boyd, Opt. Express 18, 5562 (2010).

DHIP 20174

Inv20a-4

H. KimFast calculation of wide viewing angle depth-map computer-generated hologram
Hwi Kim,* Sungjae Park, and Jonghyun Lee
Department of Electronics and Information Engineering, College of Science and Technology, Korea University,
Sejong-Campus, 2511 Sejong-ro, Sejong 30019, Korea
hwikim@korea.ac.kr
OCIS codes: (090.2870) Holographic display; (090.1760) Computer holography
In this presentation, we intoduce our recent research on on-going classical theme of computer-generated
holograms (CGHs). The wide-viewing angle depth-map CGH is designed and related idea to enhancecomputational speed is tested. The wide viewing angle computer-generated hologram (CGH) shows realistic andhigh-quality holographic three-dimensional (3D) images, and so much attention and research effort have been
devoted to develop complex-modulation and full-color CGHs [1-2]. However, the design and fabrication of fullcolor complex modulation CGH remains challenge and also the computational efficiency of the design of wideviewing angle CGH is still limited. It requires a lot of computational time and great memory. Therefore, fastcalculation method is an important key element of CGH research [3].
In this paper, we introduce the localized wide viewing angle depth-map CGH calculation method and check the
calculation efficiency enhancement. The localization method is the spatial and frequency domain division of thedepth-map image at regular intervals. The sub-division area with non-zero image signal is calculated, if not, thecalculation is skipped. The sub CGHs representing the sub-division images are coherently stamped in the CGH
plane. The schematic diagram of the process is represented in Fig. 1(a). In Fig. 1(b), it is seen that the computation
time decreases as the number of sub-region increases for several cases of CGHs with various resolution. Also, thegraph shows that the enhancement of the computational efficiency becomes more vivid with an increase of CGH
resolution. It can be said that the ultimate goal of our research is the development of the optimized parallel fastalgorithm of the high-definition wide viewing angle depth-map CGH with high quality.
(a)

(b)

Fig. 1. (a) The schematic diagram of the localized localization method, (b) computation time with resolution
Acknowledgment
This work was supported by the Industrial Strategic technology development program (10052641, Developmentof the commercialization platform technology for diffractive optical element based on 3D surface nanostructure
for full-color implementation) funded by the Ministry of Trade, industry & Energy (MI, Korea).
References
1. Y. Tsuchiyama, K. Matsushima, S. Nakahara, and Y. Sakamoto, "Full-Color High-Definition CGH Using Color
Filter and Filter Design Based on Simulation," in Imaging and Applied Optics 2016, OSA Technical Digest(online) (Optical Society of America, 2016), paper DW5I.4.
2. K. Matsushima and S. Nakahara, "Extremely high-definition fullparallax computer-generated hologram createdby the poly-gon-based method," Applied optics 48, H54-H63 (2009).
3. J. Cho, J. Hahn, and H. Kim, "Fast reconfiguration algorithm of computer generated holograms for adaptive
view direction change in holographic three-dimensional display," Optics Ex-press, Vol. 20, No. 27, pp. 2828228291, (2012).

DHIP 20175

Inv20a-5

Y. Akao

Compound-eye imaging for forensics
Yoshinori Akao
Information Sci. Sec., National Research Institute of Police Science, Kashiwa, Chiba 277-0882, Japan
Tel.: 81-4-7135-8001, E-mail: akao@nrips.go.jp
OCIS codes: (110.2970) Image detection systems; (110.4190) Multiple imaging; (120.4630) Optical inspection

Compound-eye imaging system [1] is fascinating since multiple images are captured within single shot whereas
each image has different properties. It is so versatile that the field of forensics are also included within its
application range. In this presentation, we show examples of efficient gonio-imaging [2] by compoud-eye imaging
system for forensic document examination.
Fig. 1(a) describes compound-eye imaging system for the examination of holograms [3]. It has four (2 by 2)compound eyes which captures sample images at different observation angles. With the combination ofilluminating light sources at 12 directions achieved gonio-imaging at 48 kinds of geometries. Objective lensplaced at its focal length from sample surface made the diffraction light from hologram sample quasi-parallel.
Compound-eye lens on image sensor resulted in four images with different diffraction angles. The result showed
different color of diffracted light was imaged at each individual eye. The system is small-sized and handheld. All
optical end electronic devices are in the housing, therefore hologram inspection outside of dark room was enabled.
Fig. 1(b) shows compound-eye imaging system for the examination of handwitings [4]. Compound-eye camera(Pi Photonics, TOMBO USB3.0), which has nine (3 by 3) individual eyes with 1.2 mm interval between adjacentcompound-eye, was used for the acquisition of compound-eye image. In front of the camera, coaxial illumination
module (Optomecha Engineering, DRS-5) was installed. The gloss specular reflection was observed at the bottom
or side wall of handwritten strokes in nine individual images of a compound-eye image.
Multi-angle imaging that captures reflected light at different angle were achieved based on compund-eye opticalsystems. It is one of the promising apprication to examine holograms or handwritings in the field of forensic
document examination. High resolution imaging and zooming remain as future works.
Color image sensor（1/4”, CMOS, VGA）

Lens array
（2×2）

2

1

3

4

Individual
eye
1
2
3
4

Polar
angle

Azimuth
angle

5°

35°
145°
215°
325°

Compound-eye
camera（3×3）

Coaxialillumination
moduleObservation angle at each individual eye
Objective lens2

1Overview of the system

Overview of sensor headCompound-eye
camera（3×3）

Light source(white LED)

3

Parallelillumination

4Black flocked paper
Prism

Sample
6 mm

A scene of using the system

Optical configuration

Half prism
Optical configuration

Compound-eye image of a hologram (grating image)Compound-eye image of handwriting(A numeral “6”)3 mmFig. 1. Compound-eye imaging for forensic examination: (a) hologram, (b) handwriting.
Acknowledgment
Author express gratitude to Prof. Tanida of Osaka University for his supervising in the development of systems.
A part of this work was supported by JSPS KAKENHI Grant Number 15K00260.
References
1. J. Tanida et al., Appl. Opt., 40, 1806 (2001).
2. Y. Akao et al., Opt. Exp., 19, 3353 (2011).
3. Y. Akao et al., Proc. JSAP-OSA Joint Symposia 2015, 15p-2F-14 (2015).
4. Y. Akao, Proc. DHIP2016, 186 (2016).

DHIP 20176

Inv20p-1

J. Hahn

3D display making light field inside volume
Joonku Hahn
School of Electronics Engineering, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu 41566,
South Korea
Tel.:82-53-950-5514, E-mail: jhahn@knu.ac.kr
OCIS codes: (100.6890) Three-dimensional image processing; (220.0220) Optical design and fabrication.
In general, light field is formed by integral imaging [1] and it resembles Talbot image as shown in Fig. 1(a). Directional
displays covering closed surface makes light field inside volume [2] and they can be categorized according to the locationand convergence of projection optics. When the projection optics are aligned along a circle [3,4] the light field is formed asshown in Fig. 1(b). The light fields with converging optics [5,6] and diverging optics [7] are the same inside volume asshown in Figs. 1(c) and (d).

(a)

(b)

(c)

(d)

Fig. 1. Light fields from (a) planar and (b) cylindrical alignment of projection optics. Light fields fromrotation of (c) converging and (d) diverging projection optics.
Acknowledgment
This work was supported by Samsung Research Funding Center of Samsung Electronics under Project Number
SRFC-IT1301-07.
References
1. J. Hahn, Y. Kim, and B. Lee, “Uniform angular resolution integral imaging display with boundary folding
mirrors,” Appl. Opt. 48, 504-511 (2009).
2. H. Kim, J. Hahn, and B. Lee, “Image volume analysis of omnidirectional parallax regular-polyhedron three-dimensional
displays,” Optics Express 17, 6389-6396 (2009).

3. G. Choi, H. Jeon, H. Kim and J. Hahn, “Cylindrical directional display with multiple spinning slits,” The 16th
International Meeting on Information Display, Jeju, Korea, P2-65, Aug. 2016.
4. M. Jung, C. Lee, S. Lim and J. Hahn, “Computation of elemental images in convexly curved lenticular display,”
The 16th International Meeting on Information Display, Jeju, Korea, P2-67, Aug. 2016.
5. Y. Lim, K. Hong, H. Kim, H.-E. Kim, E.-Y. Chang, S. Lee, T. Kim, J. Nam, H.-G. Choo, J. Kim, and J. Hahn,“360-degree tabletop electronic holographic display,” Optics Express 24, 24999-25009 (2016).
6. D. Heo, M. Kim, G. Choi, and J. Hahn, “Full parallax crystal ball three-dimensional display,” The 17th
International Meeting on Information Display, Busan, Korea, F46-4, Aug. 2017.
7. K. Kim, S. Lim, H. Kim and J. Hahn, “Full-color tabletop light-field display,” Digital Holography and ThreeDimensional Imaging, Heidelberg, Germany, paper DT4D.5, July 2016.

DHIP 20177

Inv20p-2

N. TateNanoscale character extraction for nano-optical metric system
Naoya Tate
Dept. of Electrical Engineering and Computer Science, Kyushu University,
Fukuoka, Nishi-ku, 744 Motooka, Japan
Tel.:81-92-802-3694, E-mail: tate@ed.kyushu-u.ac.jp
OCIS codes: (060.4785) Optical security and encryption; (200.3050) Information processing; (350.4238)
Nanophotonics and Photonic crystals

Recently, we investigated the realization of advanced physical security that we defined as nano-optical metrics[1]. In the case of the simplest setup consisting of a sample and a reader, their performance is affected bytechnological difficulty in duplicating nanoscale structures and fundamental impossibility of estimating thecharacteristic behavior of optical near-field interactions [2] between the sample and the reader. In order toexperimentally demonstrate our concept, it is necessary to realize the stable detection of nanoscale fluctuations
due to optical near-field interactions and to appropriately define their characteristics for the development of ouroriginal authentication algorithm. In this paper, we mainly focus on the latter topic. Firstly, for mathematicaldemonstration, the signal detection via the optical near-field interactions is modelized and the corresponding
nanoscale fluctuations are calculated. Then, the characteristics are quantitatively defined for further studies.
The prototype setup of nano-optical metrics is based on non-scanning near-field optical microscopy (NOM). In
the field of nano-photonics, the probe is continuously fluctuated to maintain the distance between the sample.
During the fluctuations, based on the size resonance effect of optical near-field interaction [3], various scales ofinteractions between the probe and the target are sequentially induced. This means that only by fluctuations on asingle detection point, the probe induces interactions between not only the structure just beneath it but also thesurrounding structures on the sample. Therefore, readout signals during the fluctuations are expected to include
some information about spatial structures of the sample. This is one of the most important matters of nano-optical
metrics, because the precise scanning process is not suitable for actual use as a common security system.

Fig. 1. (a) A model of nano-scale fluctuations between the sample and the probe, which is modelizedusing a combination of spheres. (b) Detecting distance dependency of the calculated interactions.
Figures 1(a) and (b) show one of the simplest model of optical near-field interactions and the calculated resultswith some variations in the detecting distance between the sample and the probe. Results in Fig. 1(b) indicatesthat while one of the five similar spheres were displaced by another sphere with a different size, as shown in Fig.
1(a), some clear differences are surely obtained during the fluctuations. As further studies, we are now discussing
the definition of their characteristics and development of our original authentication algorithm based on thedefinition. This work was supported by JST KAKENHI Grant Number JP17K14125.
References
1. N. Tate, et al., Appl. Phys. A, Vol. 121, Issue 4, pp. 1383-1387 (2015).
2. M. Ohtsu, Dressed Photons—Concepts of Light-Matter Fusion Technology (Springer, Berlin, 2013).
3. S. Sangu, et al., J. Microscopy, Vol. 202, pp. 279-285 (2001).

DHIP 20178

Inv20p-3

S.-Y. Lee

Reflective-type reconfigurable digital hologram panel using
Ge2Sb2Te5 phase change material
Seung-Yeol Lee1
School of Electronics Engineering, Kyungpook National University, Bukgu, Daegu 702-701, Republic of Korea
Tel.:82-53-950-6608, E-mail: seungyeol@knu.ac.kr

1

OCIS codes: (240.6680) Surface plasmons; (280.4788) Optical sensing and sensors; (310.6628) Subwavelength
structures, nanostructures

Recently, digital hologram using various spatial light modulators (SLMs) has been reported for developing a
dynamic hologram movie system. For a high-resolution hologram image with wide viewing angle, an opticalmodulating device below 1~2 μm scale pixel pitch are needed which has reconfigurable or tunable characteristic.
According to our previous works, both reconfigurable characteristic and high compactness of 1 μm scale pixel
pitch have been simultaneously achieved by using a thermally-driven phase change material, Ge2Sb2Te5 (GST) [1].
It has been known that the reflection spectrum of thick GST is usually gray due to its broadband highly loss
characteristics. However, the ITO-GST-ITO composite layer can provide its own structural color depends on the
thickness of surrounding ITO, when a multiple reflection inside the ITO cavity is enhanced due to the Fabry-Perot(FP) resonance. When such kind of composite layer is applied, diffraction efficiency caused by phase change ofthin GST region was dramatically enhanced and absorption characteristic caused by GST layer is also increased[2].
Based on an absorption resonance of ITO-GST-ITO composite layer, a reconfigurable digital hologram with 1
μm scale can be written by excimer laser lithography on thin ITO-GST-ITO composite film. We also find that FP
resonances of dielectric layer have significant role for determining the optimized GST film location, and by using
such characteristics, it is also possible to make the light illuminating to digital holography pattern can bediffracted wavelength-selectively. Numerical simulations based on rigorous coupled wave analysis (RCWA) has
been shown to find the appropriate location of thin GST film within the dielectric layer.
Moreover, nano-slit structure that can sustain surface plasmon polaritons (SPPs) has been numerously
researched for shaping the subwavelength-scale optical signals. For example, increasing the intensity of light
passing through the nano-slit is quite important to improve the performance of light detection using the nano-slit.
Therefore, methods for optical reflection phase control within subwavelength size unit pixel using phase changematerials (PCMs) and plasmonic metasurfaces are quite important for developing novel type of 3D opticalimaging system. Diffractive optical systems such as PCM-based hologram panel, plasmonic metalens, andpolarization multiplexing techniques of surface plasmon polaritons will be presented.

Acknowledgment
This work is supported by the National Research Foundation of Korea and the Ministry of Science and ICT (NRF2017R1C1B2003585).
References
1. S.-Y. Lee, Y.-H. Kim, S.-M. Cho, G. H. Kim , T.-Y. Kim, H. Ryu, H. N. Kim, H. B. Kang, C.-Y. Hwang, and C.S. Hwang, Sci. Rep. 7, 41152 (2017).
2. P. Hosseini, C. D. Wright and H. Bhaskaran Nature 511, 206–211 (2014).
3. S.-Y. Lee, H. N. Kim, Y.-H. Kim, T.-Y. Kim, S.-M. Cho, H. B. Kang, and C.-S. Hwang, ETRI J. 39, 3, 390-397,(2017).

DHIP 20179

Inv20p-4

H. Arimoto, et al.

Unstained tumor detection in digestive organs based on
autofluorescence spectroscopy
Hidenobu Arimoto1, Keiichiro Kagawa2, Yoji Sanomura3, Shigeto Yoshida4, and Shinji Tanaka3
1
Electronics and Photonics Research Institute, National Institute of Advanced Industrial Science andTechnology, Tsukuba, Ibaraki 305-8565, Japan
2
Research Instituite of Electronics, Shizuoka University, Hamamatsu,Shizuoka 432-8011, Japan3
Department of Endoscopy, Hiroshima University Hospital, Hiroshima, Hiroshima 734-8551, Japan
4
Department of Gastroenterology, JR Hiroshima Hospital, Hiroshima, Hiroshima 732-0057, Japan
Tel.:81-29-861-7880, E-mail: arimoto-h@aist.go.jp
OCIS codes: (170.0170) Medical optics and biotechnology; (170.6280) Spectroscopy, fluorescence and lumin
escence; (170.2150) Endoscopic imaging

Early detection of the tumors in digestive organs is quite important for the better prognosis. In the endoscopic
diagnosis, narrow band imaging (NBI) is widely used. NBI investigates angiogenesis patterns using particular
spectral band for the illumination light so that the angiogenesis is clearly seen. However, earlier detection of thetumor is possible if we can measure the metabolic change which is caused by the tumor cell divisions. For thispurpose, we focus our attention on the coenzymes NADH and FAD those density ratio change according to theoxygen partial pressure in an organ. The ratio of NADH and FAD is estimated from their autofluorescence spectra,
and the tumor region is determined by the REDOX index which is defined as the intensity ratio of the
autofluorescence intensities.

Fig. 1. Example of the REDOX images for the digestive tumor detection.
In a tumor cell, NADH increases while FAD decreases compared to the normal cell. Then we use two excitation
wavelengths 365 and 405 nm; 365 nm excites almost only NADH while 405 nm excites both NADH and FAD.
Hence the intensity ratio [365 nm ex.]/[405 nm ex.] (ratio REDOX index) is expected to increase in the tumor
region. Lower images in Figure 1 are the 2D map of the REDOX index (REDOX image), expecting the tumor
region appears bright. Sample A, B, and C are the resected digestive tissues including tumor in their middle areas.
The REDOX image of sample B indicates the tumor region with the bright area as we expected. We took 32
REDOX images in total, and 78% of the REDOX images show the positive contrast. However the REDOX
images of sample A and C have the negative contrast and weak contrast, respectively, probably because of theappearance of the collagen in the lower layer of the tissue. More precise determination may be possible byintroducing additional parameters.
References
1. H. Arimoto, A. Iwata, K. Kagawa, Y. Sanomura, S. Yoshida, S. Kawahito, and S. Tanaka, Proc. SPIE
10068, Imaging, Manipulation, and Analysis of Biomolecules, Cells, and Tissues XV, 100681L (2017).
2. M. Ozaki, K. Kagawa, H. Arimoto, Y. Kominami, Y. Sanomura, S. Yoshida, MW. Seo, S. Kawahito, and S. Tanaka, 2015 37th Annual International Conference of the IEEE Engineering in M
edicine and Biology Society (EMBC), 5879 (2015).

DHIP 201710

Inv20p-5

T. KimRecent progress on 3D target tracking using optical scanning holography
Taegeun Kim
E-mail: takim@sejong.ac.kr
Dep. of Electrical Eng., Sejong Univ. Korea
OCIS codes: (090.1995) Holography; (070.0070) Fourier optics and signal processing

Three-dimensional (3D) target tracking using optical scanning holography (OSH) has a long standing history [15]. In first generation, we propose an algorithm based on Wigner distribution analysis, which extracts depth
location of a matched object without searching process.[1,2] However, this technique is limited to the 3D location
extraction of the 3D matched object and the 3D matching process is not robust to rotation and distortion of thetarget object. In second generation, an algorithm which extracts depth location of an object without priorknowledge of target object [3,4]. In the proposed algorithm, we first record the complex hologram of a target
object using OSH. After that, we synthesize a real-only spectrum hologram and extract the depth location of theobject using Wigner distribution or axis transformation after power-fringe adjusted filtering. [3,4] Figure 1,2.
show OSH that records the complex hologram of an object and the flow chart that extracts the depth location of
the object. This makes it possible to extract the depth location of an object without prior knowledge. Using thedepth location, we get the focused image of the object by digital refocusing. Here we note that hologram contains
information of depth as well as lateral distributions of an object as a form of fringe pattern and the phase of acomplex hologram recorded by OSH in incoherent mode is not contaminated by speckle noise. This make thefringe analysis of the hologram recorded by OSH give the depth location of a target object and focused image
without prior knowledge. Meanwhile, in computer vision area, rotation and distortion invariant image recognition
algorithms have been proposed. However, these rotation and distortion invariant features extraction techniques arelimited to 2D because the object’s image is the projection of a 3D object onto 2D plane and does not contain depth
information. Recently, we propose a 3D target recognition and tracking technique[5]. This composes two stages.
One is feature extraction stage and the other is recognition and location extraction stage. In the feature extraction
stage, we first record the complex hologram of a reference object using OSH. Second, we extract the depth
location of the object by searching the focused depth using sharpness function metric. Third, we recover the 2D
image of the object by reconstructing the hologram using the depth location. Fourth, we extract the features of theobject using SURF(speeded up robust feature) algorithm.

Fig. 1. Optical Scanning Holography (BS: beam splitter, M: mirror)

DHIP 201711

Inv20p-5

T. KimFig. 2. Depth detection algorithm [3,4]In the recognition and location extraction stage, first we record the complex hologram of a target object using
OSH. After that, we extract the depth location by searching algorithm and matches featuers of the target object
using SURF algorithm. Matching the features of the reference and target objects gives the lateral location of thematched object. This gives the lateral location of the rotation and distortion invariantly recognized target object.
Icluding the depth location of the target object extracted in the depth searching process, finally, we extract 3D
location of recognized target object.
Acknowledgment
This research was supported by the MSIT(Ministry of Science and ICT), Korea, under the ITRC(Information
Technology Research Center) support program(IITP-2017-2015-0-00448) supervised by the IITP(Institute forInformation & communications Technology Promotion)
References
1. T. Kim and T.-C. Poon, Opt. Eng., 38(12), 2176 (1999).
2. T. Kim and T.-C. Poon, J. Opt. Soc. Am., 17(12), 2025 (2000).
3. T. Kim and T.-C. Poon, Opt. Eng., 41(6), 1331 (2002).
4. T. Kim and Y.-S. Kim, JOSK, 14(2), 104 (2010).
5. U.-J. Lee, Y.-S. Kim and T. Kim, Proc. of Photonics Conference 2016, 287, (2016).

DHIP 201712

Inv20p-6

S. Choi

Multi-frequency swept en-face optical coherence microscopy withsupercontinuum comb for in-vivo measurement of inner ear
Samuel Choi1,4, Fumiaki Nin2,4, Takeru Ota2,4, Keita Sato3, Takamasa Suzuki3 and Hiroshi Hibino2,4
1 Niigata University, Department of Electrical and Electronics Engineering, Niigata, Japan
Tel.:81-25-262-6761, E-mail: schoi@eng.niigata-u.ac.jp
2 Niigata University, School of Medicine, Department of Molecular Physiology, Niigata, Japan
3 Niigata University, Graduate School of Science and Technology, Niigata, JapanOCIS codes: (180.3170) Interference microscopy; (110.4500) Optical coherence tomography; (170.3880)
Medical and biological imaging; (120.7280) Vibration analysis

A variety of optical coherence tomography (OCT) techniques are being widely adopted for imaging cross-section
and vibrational distributions in subsurface tissue [1]. As concrete examples, the phase-sensitive spectral domain(SD)-OCT [2], and swept-source (SS)-OCT [3] have been developed for measuring high-speed vibrations fromvarious surfaces within the organ of Corti and the tympanic membrane. However, these techniques involve
scanning single measurement points along the two lateral dimensions based on fiber-optic OCT. Therefore,
conventional SS-OCT and SD-OCT cannot simultaneously measure the wide-range dynamics of bio-tissues,
which is thought to be crucial for elucidating the biomechanics. To address this issue, tomographic wide-field
vibrometry, which we term “multifrequency swept optical coherence microscopic vibrometry[4]” (MS-OCMV)
has been developed. The irradiation power in MS-OCMV was insufficient to detect the reflection from the organof Corti (sensory epithelium) due to lack of output power of the super luminescent diode (SLD) employed as alight source. In this paper, we report the improvement of MS-OCMV system employing a supercontinuum (SC)light source instead of SLD. In-vivo en-face OCT and vibrational measurements of guinea pig sensory
ephitherium in organ of Corti were successfully conducted as shown in Fig. 1(b). The effective depth scan range
and the imaging resolution in the OCT mode were approximately 980 m and 1.8 m, respectively. 3-D volumedata acquisition speed was 2Gvoxel/sec. In the vibrometry mode, the vibration distributions with the sinusoidal
sound inducing of 15-25 kHz, 90 dBspl were imaged on the microscopic en-face images. The effective detectablevibrational amplitude was approximately 10 nm in the in-vivo measurement.
(b)

(a)

Fig. 1 In-vivo measurement results, (a) 3D volume and (b) vibration distributions of sensory epithelium.
Acknowledgment
This work was supported by AMED-CREST, AMED, Grant-in-Aid for Scientific Research (B) (16H03164) and Grant in-Aid
for Young Scientists (A) (15H05683).

References
1. N. Choudhury, et al. , Hear. Res. 220(1-2), 1–9 (2006).
2. S. S. Gao, et. al., J. Neurophysiol. 112(5), 1192–1204 (2014).
3. D. MacDougall, et al., Opt. Express 7(11), 4621–4635 (2016).
4. S. Choi, et. al., Biomed Opt. Express 8(2), 608-621 (2017).

DHIP 201713

p20-1

T. Matsuzaki

Polarization Color Display Using Index Matching
Toshiki Matsuzaki, Huangyi Qin and Kenji Harada
Dept. of Computer Science, Kitami Institute of Technology, 165 Koen-cho, Kitami, Hokkaido 090-8507, Japan
Tel.: 81-157-26-9357, E-mail: m1652400113@std.kitami-it.ac.jp
OCIS codes: (260.1440) Birefringence; (260.5430) Polarization; (330.1690) Color;
The polarization color is displayed by sandwiching the retarder film between two polarizer and by incidence ofwhite light. The color tone varies depending on the arrangement angle of the retarder film and the stacking
number of the retarder films. In the conventional polarization color display, the difference in the number ofretarder films is observed as a difference in transmittance without using a polarizer, and there is a possibility that adisplay image is guessed. This causes loss of pleasure and wonder when you see the images, which is anadvantage of polarization color display. Also, when applying polarization color to the art field, it will cause harmto the color of the work.
Therefore, in this research, we propose a method of index matching using optical adhesive and make thetransmittance uniform. Optical adhesives have high transmittance and refractive index matching and are known tobe suitable for bonding optically precise instruments such as optical fibers. It also cures rapidly by ultraviolet
irradiation (sunlight, UV light, etc.). The transmittance when using the optical adhesive was measured using aspectrophotometer and compared with the conventional polarization color display. Also, it was applied to apolarization color display in which no difference in the number of retarder films was observed.
The refractive index of the optical adhesive used in this research is 1.56. The refractive index of the retarder film
used is 1.58. The transmittance 𝑇[%] when light incidents a substance with a refractive index 𝑛𝑎 from asubstance with a refractive index 𝑛𝑏 is calculated by2𝑛 −𝑛

𝑇 = (1.0 − |𝑛𝑎+𝑛𝑏| ) × 100 .
𝑎

(1)

𝑏

Therefore, the transmittance when light incidents the air from the retarder film is about 94%. On the other hand,
the transmittance when light incidents the optical adhesive from the retarder film is about 99%. Therefore, byadhering the retarder films with the optical adhesive, the transmittance is improved. Figure 1 show a state of 1 to
10 quarter wave retarder films stacked and observed. The numbers in the figure 1 indicate the number of films.
Compared to Fig. 1(a), Figure 1(b) shows that the transmittance of the portion with a large number of retarderfilms is improved and it is difficult to observe the difference of the stacking number of retarder films. Also, Figure1(c) and 1(d) shows that the optical adhesive does not affect the polarization color. Figre 2 shows a graph obtainedby measuring the transmittance when white light is incident. Without the optical adhesive, the transmittancedecrease from 90.2% to 30.0% by stacking 10 retarder films. On the other hand, when the optical adhesive is used,a high transmittance of 81.6% is maintained with 10 retarder films . The transmittance when stacking the retarderfilms ware improved using index matching by the optical adhesive. In this presentation, we will also exhibit
polarization color art using this transmittance improvement method.

1

2

3

4

5

6

7

8

9

10

2

3

4

5

6

7

8

9

10

(a) no optical adhesive, no polarizer(b) with optical adhesive, no polarizer
1

2

3

4

5

6

7

8

9

10

9

10

(c) no optical adhesive, with polarizer
1

2

3

4

5

6

7

8

with optical adhesive
Transmittance [%]1(d) with optical adhesive, with polarizer

no optical adhesive

Number of films
Fig. 2. Transmittance of each number of films

Fig. 1. Transmission state of retarder films

DHIP 201714p20-2

H. QINPolarization color optimization of birefringent material
Huangyi Qin, Toshiki Matsuzaki and Kenji Harada
Dept. of Computer Science, Kitami Institute of Technology, 165 Koen-cho, Kitami, Hokkaido 090-8507, Japan
Tel.:81-0157-26-9357, E-mail: m1752400132@std.kitami-it.ac.jp
OCIS codes: (260.1440) Birefringence; (260.5430) Polarization; (330.1690) Color;

Retarder film exhibits polarization color by polarizer. We propose a method that uses waveplate and polarizers todisplay polarization color. The output color can be designed hardly by mathematic way analytically. Because thecalculation contains invertible functions which make the computation of output color unsolvable. To make thiscolor design possible, we introduce differential evolution algorithm.
Jones Matrix is a proper tool for discrimination of interference color phenomena. A retarder can be
described as below by Jones Matrix.
 i R cos  sin   cos  sin   e 0M ( ,  )  R 
 sin  cos i sin  cos 



e  
 0
R is retardation of the retarder and lambda is incident light’s wavelength.
M out  M n    M 2  M 1
1 0
0 0
  M out    ( M out )1, 2
T ( M n ,, M 2 , M1 ,  )  
0 0
0 1
780
780
780
S ( ) ･T (..., ) ･x( )d
S ( ) ･T (..., ) ･y ( )d
S ( ) ･T (..., ) ･z ( )d
380
380
380
X
,Y 
,Z 
780
780
780
S ( ) ･y ( )d
S ( ) ･y ( )d
S ( ) ･y ( )d
380
380
380
To optimize  M n ,  ,  M 2 ,  M1 by given XYZ we introduce differential evolution algorithm (DE). DE is similar













to genetic algorithm (GA) which has steps of mutation, recombination and selection. Comparing to GA, DE’s
mutation has a very simple form as equation (3). Recombination described as equation (4). Selection is showed as
equation (5).

v  g1  F g 2  g 3 .........(3 )At equation (3), g1, g2 and g3 are individuals chosen from the population group. F is constant called mutation
factor. v is the mutated target.
 v j if rand[0,1)  CR or j  randint[0,dim]uj  
.........(4 ) g1, jAt equation (4), j is the index of data dimension. In our previous research, we thought to use 5 retarder films isproper choice. Thus, the data here have 5 dimensions of each film’s rotation angle. CR is called crossover ratio.

 u if f(g1 )  f(u)new g1  .........(5 ) g1
At equation (5), f is the fitness function which here is squared error of given XYZ.
References
1. K. Harada, D. Sakai, Y. Sone, Y. Harada and S. Kamemaru, Jpn. J. of Appl. Phys. Education, 34 (2010) 35-40[in Japanese].
2. Storn, R.; Price, K. Journal of Global Optimization. 11: 341–359 (1997)

DHIP 201715p20-3

R. Takagi

Object recognition through a multi-mode fiber based on machine learning
Ryosuke Takagi, Ryoichi Horisaki and Jun Tanida
Graduate School of Information Science and Technology, Osaka University,
1-5 Yamadaoka, Suita, Osaka 565-0871, Japan
Tel.: +81-6-6879-4398, E-mail: r-takagi@ist.osaka-u.ac.jp
OCIS codes: (060.2350) Fiber optics imaging; (070.5010) Pattern recognition; (110.0113) Imaging through turbid
media; (110.1758) Computational imaging;Sensing and control of light in optically scattering media like in vivo biological tissues have been important
problems. Against these problems, researchers have proposed many approaches based on structured illumination[1], integral photography [2], estimating the scattering process [3] and so on. These methods are effective, butthey require complex setups like requirements of a reference light, multiple measurements or heavy computationalcosts for the reconstruction.
In this study, we propose a machine-learning-based approach for object recognition through a multi-mode fiber(MMF), which is known as a strongly scattering medium. In this case, optical setup is simpler because of a singleshot measurement and the computational costs are mitigated by omitting the reconstruction process. The method
consists of training and test processes. In the training process, speckle patterns from face and non-face objects inthe training database are provided for the classifier based on machine learning. In the test process, unknown
speckle patterns are categorized into the two classes of the face and non-face. The support vector machine (SVM),
adaptive boosting (AB), neural network (NN) were used to compare their efficiencies [4].
The optical setup in our experimental demonstration is shown in Fig. 1. Object images are displayed on a spatial
light modulator (SLM). The SLM is illuminated with a collimated beam from a laser diode. The intensity patterns
after propagating through the MMF are captured with an image sensor without reference light. In the training
process, the radial basis function was applied to the SVM. The number of weak learners in the AB was 500. The
NN had one hidden layer with ten nodes and it was constructed based on the back-propagation method.
The graph in Fig. 2 shows the relationship between the number of sampling pixels in a speckle pattern and theaccuracy rate of the binary classification with the three algorithms. In this case, the number of training pairs of theobjects and speckles was 2000 (face class: 1000, non-face class: 1000). The number of the test pairs was 400 (faceclass: 200, non-face class: 200). The accuracy rates at the 800 sampling pixels of the SVM, the AB, the NN were
92.2%, 87.7% and 89.1%, respectively. The accuracy rates of the SVM were the best in any case.

Fig. 1. Optical setup.

Fig. 2. Accuracy rate with each numberof sampling pixels.

References
1. V. Durán. et al., Opt. Express 23, 14424-14433 (2015).
2. M. Cho and B. Javidi, Disp. Technol. J. 6, 544-547 (2010).
3. M. Kim. et al., Opt. Express 23, 12648-12668 (2015).
4. R. Takagi. et al., Opt. Rev 24, 117-120 (2017).

DHIP 201716

p20-4

R. SatoSpectral imaging based on single pixel camera
Ryo Sato, Kazuki Ota and Yoshio Hayasaki
Center for Optical Research and Education (CORE), Utsunomiya University
7-1-2 Yoto, Utsunomiya 321-8585, Japan
Tel.:+81-28-689-7128, E-mail: sato_ry@opt.utsunomiya-u.ac.jp
OCIS codes: (110.0110) Imaging systems; (300.0300) Spectroscopy; (110.1758) Computational imaging

Spectral imaging is very effective in various fields of biology, food science, health science, medicine, remotesensing, and astronomy. It acquires the wavelength information in addition to the two-dimensional light intensity
distribution. There are two different approaches. In one approach, an object is illuminated with a light sorce withnarrow wavelength width and the change of the wavelength. The transmission, reflection, and scattered light fromthe object are detected by an ordinary image sensor. In the other approach, an object is illuminated by a light witha wide wavelength, and the light from the object is detected by a spacially-custamized camera with a spectral
separation ability.
In this paper, we propose a spectral imaging based on a single pixel camera. The single-pixel camera [1] is composed of optical coding masks and a photo detector. An object image is spatially encoded by the masks and the light intensity summation of the encoded image is detected by the photo detector.
And the light detection was iterated the same number of the pixels while changing the masks. The objec
t image is reconstructed by the inverse matrix calculation from the encoded images and the light detecti
ons. The number of the light detection is reduced by the compressive sensing technique [1]. The biggest
feature of the single-pixel camera can perform an imaging with a photodetector, that is, without an imag
e sensor. Therefore, it has simple optics and simple electronics, and consequently it can perform the ima
ging in a wide variety of wavelengths with very low cost.
A spectral imaging based on a single pixel camera (single pixel spectral camera) is easily constructed byreplacing the photodetector to a conventional spectroscope, in this research, with an optical fiber input. The
coding mask consists of holes on a substrate for ultrawideband spectroscopy in future. The masks are placed ona rotatory disk. It has no wavelength dependence except for an optical absorption of air.
The light source was a halogen light source. The 4 × 4 coding mask is made of holes arranged on thecircumference of the disk and switched by rotation of the disk. The encoded image was detected by a fiber-based
spectroscope (C7473, Hamamatsu) through a lens. The light intensity values were continuously detected while thedisk was rotating, and the peak values corresponding to each mask were extracted at the indication position.
Spectral images had a spectrum from 300 nm to 700 nm with same spectral resolution of the spectroscope.
Figure 1 shows an object composed of red and blue films, and the spectroscopic images with 4 x 4 pixels. The
spectrum of the obtained image corresponded to the spectral properties of films.

Figure 1 Object composed of red and blue films and the obtained spectroscopic images with 4 x 4 pixels.
The color is pseudo.
Reference[1] M. F. Duarte, M. A. Davenport, D. Takhar, J. N. Laska, T. Sun, K. F. Kelly, and R. G. Baraniuk, “SinglePixel Imaging via Compressive Sampling”, IEEE Signal Process. Mag. 25, 83-91 (2008).

17

DHIP 2017p20-5

K. Shimose

Aerial Volumetric Display with Pyramid Structured LED Lattice and AIRR
Kazuki Shimose1 and Hirotsugu Yamamoto1,2Dept. of Optical Engineering, Utsunomiya University, Utsunomiya City, Tochigi, 3210904, Japan
Tel.:81-28-689-7120, E-mail: hirotsugu@yamamotolab.science
2
JST.ACCEL, JapanOCIS codes: (110.0110) Imaging systems; (300.0300) Spectroscopy; (110.1758) Computational imaging
1

The aerial volumetric display is a three-dimensional (3D) aerial imaging technique that can show 3D information
intact in the air. A user can touch all light spots displayed in the depth direction. The purpose of this research is torealize an aerial volumetric display with a wide viewing angle, which is free from the occlusion problem occurringin 3D space. The occlusion problem is the inconsistency between the depth of the aerial image and the occlusion,
which occurs in the conventional aerial 3D display by use of an LED cube. Our solution employs a pyramid
structured LED lattice. Our proposed aerial volumetric display is useful for displaying realistic objects in the air.
Furthermore, it is effective for applications that intuitively show the orientation three-dimensionally in the air. As avolume display for drawing stereoscopic images directly in three-dimensional space, the three-dimensional structurethat displays different directional images according to the viewing direction has been proposed 1. For a volumetricdisplay that three-dimensionally distributes bright spots in the air to form a three-dimensional image, it has been
proposed that three-dimensional display by scanning two-dimensional plane2. However, large-scale equipment suchas scanning is required. In order to make full use of motion parallax for volumetric display, we utilize aerial imaging
by retro-reflector (AIRR)3, which features a wide viewing angle, for aerial volumetric 3D display. When an 3D LED
lattice is imaged in the air with AIRR, it is possible to form a volumetric image without a scanning mechanism.
A volumetric display by use of an LED cube and our proposed aerial volumetric display with a pyramid structured
LED lattice are shown Fig. 1. The lights from the LEDs are partially reflected by the half mirror. Then, the reflected
lights are retro-reflected on the retro-reflectors. Finally, the retro-reflected lights transmit the half mirror and form
aerial images of the LEDs. As shown in Fig. 1(a), since the LED of Layer 3 in the LED cube is occluded by the
LED of Layer 1 and Layer 2, not only the light utilization efficiency decreases, when forming an image in the air,an occlusion problem occurs in which the aerial image of Layer 3 to be observed in front is hidden in aerial imageof Layer 1 and Layer 2 formed at the back. We avoid this occlusion problem by using pyramid structured LED
lattice. As shown in Fig. 1(b), by designing that the LED of Layer 3 does not overlap the LED of Layer 1 and Layer
2, it is possible to observe the aerial image of all the LEDs from the range of the fixed viewing angle.
Experimental results are shown in Fig. 1(c), (d) and (e). Even with the naked eyes, it was confirmed that a threedimensional arrow was formed in the air. Furthermore, observations of the aerial image using the screen are shownin Fig. 1(f), (g) and (h), which show the aerial images of Layer 1, Layer 2, and Layer 3, respectively. We haveconfirmed that each aerial image is formed at the different depths.

Fig. 1. Aerial volumetric display by use of (a) an LED CUBE and (b) a pyramid-shape LED array.
Observations (c) from a left, (d) in front, (e) from a right of the aerial image, screen observations of (f)Layer 1 LEDs, (g) Layer 2 LEDs, and (h) Layer 3 LEDs.
References

1. R. Hirayama, et al., Opt. Exp. 24, 7319 (2016).
2. D. Miyazaki, et al., Opt. Exp. 14, 12760 (2014).
3. H. Yamamoto, Y. Tomiyama, and S. Suyama, Opt. Exp. 22, 26919 (2014).
18

DHIP 2017p20-6

R. Kujime

Forming the aerial 3D image of your back in front of you with using AIRR
1

Ryosuke Kujime 1,2 and Hirotsugu Yamamoto1,2
Utsunomiya University, 7-1-2, Yoto, Utsunomiya City, Tochigi, 321-0904, Japan
Tel.: 81-28-689-6137, E-mail: r_kujime@yamamotolab.science
2
JST, ACCEL, 7-1-2, Yoto, Utsunomiya City, Tochigi, 321-0904, JapanOCIS codes: (110.6880) Three-dimensional image acquisition

In this paper, we propose a system to form the aerial 3D image of the back of a viewer in front of the viewer
without delay. The proposed system is expected to be utilized for sport training: when an athlete check their
moving form, delay influences their training. We have proposed aerial imaging by retro-reflection (AIRR) to
realize a large aerial display [1, 2]. Since AIRR forms a real image in all optical process, we can form the aerial
image of a viewer without photoelectric conversion delay.
Fundamental composition of AIRR is shown in Fig. 1. Aerial display with AIRR is composed of a light source, abeam splitter, and a retro-reflector. Incident rays are reflected on the beam splitter and impinge the retro-reflector.
The retro-reflected rays transmit through the beam splitter and form the aerial image of the light source. Aerial
image is formed at the position of the plane symmetry of the light source regarding the beam splitter.
Our proposed system in this paper is shown in Fig. 2. Our system consists of two AIRR modules and two
mirrors. The first AIRR module forms the aerial 3D image of a mirrored image of the back of an object. The rays
converging the aerial image are reflected by a mirror before the second AIRR module. The second AIRR module
forms the aerial image of the reflected aerial image. As shown in Fig. 2, the second AIRR module forms the aerial
3D image of the back of the object in front of the object. This system uses only reflection for forming aerial image.
Thus, this system can form aerial image without delay. The distance between the aerial image and the object isdetermined by the distance between the second mirror and the beam splitter in the second AIRR module, and theangle of the second mirror and the beam splitter in the second AIRR module. The Distance of the aerial image andthe object D is expressed by D = d[tan(2θ-90)-1/cos(2θ-90)+1], where d and θ are the distance between the firstmirror and the beam splitter in the first AIRR module, and the incident angle of the second mirror, which is equal
to the angle of the beam splitter in the second AIRR module.
Fig. 3 shows the theoretical curve of the distance D when d = 2000 mm. The distance increases with the angle ofthe second mirror. When θ is 45 degrees, the aerial image position is the same as the object position. Thus, thedistance can be controlled by angle of mirror.
Distance (mm)

1200
1000
800
600
400
200
0
45

50

55

60

65

70

Incident angle (deg.)

(a)
(b)
(c)
Fig. 1 (a) Configuration of AIRR. AIRR is consisted of a display, a beam splitter, and a retroreflector. (b) Configuration of proposed system. This system can form aerial image of its own back face at y
our front without delay. (c) Dependences of the distance from an object to its aerial image upon the mirror
angle.
Acknowledgment
This work was partially supported by JST ACCEL Grant Number JPMJAC1601.
References
1. H. Yamamoto, Y. Tomiyama, and S. Suyama, Opt. Exp. 22, pp. 26919-26924 (2014).
2. R. Kujime, and H. Yamamoto, Proc. IDW‘16, pp. 468-471 (2016).

DHIP 201719p20-7

M. KimMulti-layered head-mounted display for occlusion and accommodation effects
Mugoen Kim, Daerak Heo, and Joonku Hahn
School of Electronics Engineering, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu, 41566, South
Korea
Tel.:82-53950-5514, E-mail:jhahn@knu.ac.kr
OCIS codes: (100.6890) Three-dimensional image processing; (220.4830) Systems design;

Various studies of near-eye display systems have been reported [1]. Among them, the double layer display has
great advantages to integrate lots of pixels within a given area by stacking the pxels vertically [2,3]. However, thebackground image is overlaped with object images. Also, the object image is illuminated by the backgroundimage light, and the object image is blended with the backround image. The study by M. Holroyed shows thepossibility of natural three dimensional view with multi-layer structure [4]. In this paper, we propose the multilayer head-mounted display for occlusion effect and accommodation effect.
The system consists of four parts which are three liquid crystal panels of mobile phone, an optical film for
combining the panels, an external light source, and a pair of eyepieces. Three panels are used to represente thebackground image, the mask blocking the part of background image and the object image, respectively. The firstpanel is located on the focal plane of the eyepiece and expresses the background image from optically infinite.
The second panel is a masking panel that provides occlusion effects for prevent the overlap of the backgroundimage on the first panel over the object image on the third panel. The last panel expresses an object image which
is displayed at a certain distance in front of the background. It is illuminated by an additional light source from theedge of it. Figure 1 shows the structure of multi-layer head-mounted display system. This system is operated byusing a propeties of polarization state. The masking panel determines whether the background image is seen
through the object panel or not.

Fig. 1. Structure of multi-layer head-mounted display
Acknowledgment
This work was supported by Samsung Research Funding Center of Samsung Electronics under Project Number
SRFC-IT1301-07.
References
1. D. Lamman and D. Luebke, “Near-eye light field displays,” ACM Transactions on Graphics (TOG) 32, 6(2013).
2. F.-C Huang, G. Wetzstein, BA. Barsky, and R. Raskar, “Eyeglasses-free display: Towards correcting visualaberrations with comutational light field displays,” ACM Transactions on Graphics (TOG) 33, 4 (2014)
3. C. Lee, J. Seok, M. Kim, and J. Hahn, “High-resolution light field sterescope,” The 16th International Meetingon Informaton Display (IMID) (2016).
4. M. Holroyed, I. Baran, J. Lawrence, and W. Matusik, “Computing and fabricating multilayer models, ” ACM
Transactions on Graphics (TOG) 30, 6 (2011).

DHIP 201720

p20-8

B. ChoDepth resolution enhancement of computational reconstruction of integral
imaging with considering continuously non-uniform shifting pixel
Byungwoo Cho1, Hui Yun1, Kotaro Inoue1, Ki-Ok Cho1, Kyungtea Park1,2, Jungsik Koo2, Jiyong Park2, Cheol-su
Kim3,Min-Chul Lee4and Myungjin Cho1*1
Dept. of Electrical, Electronic and Control Engineering, Hankyong National University, 327 Chungang-ro,
Anseong-si, Gyonggi-do 456-749, Korea
E-mail: mjcho@hkun.ac.kr
2
3D Display Components Support Center, Gumi Electronics & Information Technology Research Institute,
Korea
3
Dept. of Electric Energy and Computer Engineering, Gyeongju University, Korea
4
Dept. of Computer Science and Electronics, Kyushu Institute of Technology, Fukuoka 820-8502, Japen
OCIS codes: (110.6880) Three-dimensional image acquisition; (100.6890) Three-dimensional image processing

Three-dimensional (3D) image sensing and visualization of integral imaging technique has been studied forseveral applications including unmanned automatic vehidcle system, object recongnition, and so on. A general
integral imaging system is composed of two primary process : pickip and reconstruction process. Recently many
computational reconstruction techniques are reported ; computational volumetric reconstruction [1], PERT [2],and so on. One of these computational reconstruction techniques is computational volumetric reconstruction.
Since conventional computational volumetric reconstruction uses the pixelated process and the number of shifting
pixels for reconstruction is the fixed integer value in general, the depth resolution of the reconstructed 3D image is
not continuous. Further, the reconstructed 3D images have insufficient quality when elemental images with row
resolution are used. In this paper, we present the new computational volumetric reconstruction technique toimprove depth resolution of the reconstructed 3D images by using continuouly non-uniform shifting pixels insteadof integer uniform shifting pixels in conventional computational volumetric reconstruction. Figure 1 is shown thereconstructed planes of the conventional computational volumetric reconstruction and our method.

Fig. 1. Result of comparison of (a) the conventional computational volumetric reconstruction method and(b) our method
Acknowledgment
This research was supported by Basic Science Research Program through the National Research Foundation of
Korea(NRF) funded by the Ministry of Education(NRF-2016R1E1A2A01952377).
References
1. M. Cho and B. Javidi, J. of Display Technol., 5, 61-65, (2009).
2. S.-H. Hong, J.-S. Jang and B. Javidi, Opt. Express, 12, 483, (2004).

DHIP 201721

p20-9K. Inoue

Pixel Blink Rate based Depth Estimation Technique in Integral Imaging with
Markov Random Field Optimization
Kotaro Inoue1, Byeongwoo Cho1, Hui Yoon1, Ki-Ok Cho1, Kyungtae Park1,2, Jungsik Koo2, Jiyong Park2, Cheol-Su
Kim3, Min-Chul Lee4, Myungjin Cho1,*
1Department of Electrical, Electronic, and Control Engineering, IITC, Hankyong National University, Korea*
E-mail: mjcho@hknu.ac.kr
2
3D Display Components Support Center, Gumi Electronics and Information Technology Research Institute,
Korea
3
Department of Electric Energy and Computer Engineering, Gyeongju University, Korea
4
Department of Computer Science and Electronics, Kyushu Institute of Technology, Fukuoka 820-8502, JapanOCIS codes: (110.0110) Imaging systems; (110.6880) Three-dimensional image acquisition

Integral imaging is expected as a convenient three-dimensional (3D) imaging and display technique since it canobtain multi-view images with single shoot using a lenslet array. However, it has a critical problem that theresolution of multi-view images will be low. Therefore, reconstructed 3D images may be also low-resolution
images. Pixel of elemental images rearrangement technique (PERT) is one of solution for this problem [1]. The
reconstructed 3D images by PERT can be obtained by pixel rearranging of the multi-view images. Although itsaves high-frequency components of multi-view images compared with conventional reconstruction algorithms[2],the defocus area of reconstructed images looks like particle noise, unlike blur images. Thus, it is difficult to apply
current depth estimation algorithms. In this study, we solve this problem using pixel blink rate in depth domain.
Figure 1 shows the optical experimental results. We compared with stereo matching based algorithm [3]. Our
results show high resolution depth maps and the optimized map by markov random field (MRF) optimizationshows better result. The number of pixels of our results are 100 times higher than conventional one.

Fig 1. Optical experimental results, (a) Original scene, (b) Reconstructed image by VCR [2],(c) Reconstructed image by PERT [1], (d) Depth maps by Jeon. et al. [3], (e) Our depth map, (f) Our depth
map with MRF optimization.
Acknowledgment
This research was supported by Basic Science Research Program through the National Research Foundation of
Korea(NRF) funded by the Ministry of Education(NRF-2016R1E1A2A01952377).
References
1. M. Cho, and B. Javidi, J. of Disp. Technol. 5(2), 61, (2009).
2. S.-H. Hong, J.-S. Jang, and B. Javidi, Opt. Express, 12, 483, (2004).
3. H.-G. Jeon, J. Park, G. Choe, J. Park, Y. Bok, Y.-W. Tai, and I. S. Kweon, CVPR2015, 1555, (2015).

DHIP 201722p20-10

H. YunThree-dimensional image sensing and visualization to enhance 3D resolution of
integral imaging
Hui Yun1, Byeongwoo Cho1, Ki-Ok Cho1, Kyungtae Park1,2, Kotaro Inoue1, Jungsik Koo2, Jiyong Park2, Cheol-Su
Kim3, MinChul Lee4 , Myungjin Cho1,*1Dept. of Electrical, Electronic, and Control Engineering, Hankyong National University, Anseong, Korea*
E-mail: mjcho@hknu.ac.kr
2
3D display Components Support Center, Gumi Electronics & Information Technology Research Institute,
Korea
3
Dept. of Electric Energy and Computer Engineering, Gyeongju University, Korea
4
Dept. of Computer Science and Electronics, Kyushu Institute of Technology, Fukuoka 820-8502, JapanOCIS codes: (110.6880) Three-dimensional image acquisition; (100.6890) Three-dimensional image processing;(090.1760) Computer holography
There is the integral imaging technique [1] that can obtain 3D information by using multiple perspective 2D
images. However, low viewing resolution, narrow viewing angle and shallow depth of focus in the integral
imaging system are still unsolved problems. Therefore, We propose a new 3D image sensing and visualization
technique to improve the lateral and depth resolutions.
In the proposed method, we assume that the 2D elemental images are important information for the 3D
performance of integral Imaging since they include lateral and depth resolutions of 3D objects. We use theconcept of the resolution priority integral imaging (RPII) and the depth priority integral imaging (DPII) [2] inpickup of proposed method. And then we anayze resolution of 2D elemental images by using characteristic ofcamera (or lens) paramater. The our proposed method is simple. In the reconstruction of the proposed method, theelement image RPII focused on the distance of object result overlaps the reconstruction image of the conventional
method using the element images of DPII.
To show the feasibility of our proposed method, we implemented experiments by using proposed method. We
represent the result images by using the proposed method in Fig. 1-(a). And also Fig. 1-(b) shows PSNR [3] forboth conventional and our methods via different reconstruction depths to evaluate the proposed method.

Fig. 1. The result of the optical experiment (a) result images (b) PSNR
Acknowledgment
This research was supported by Basic Science Research Program through the National Research Foundation of
Korea(NRF) funded by the Ministry of Education(NRF-2016R1E1A2A01952377).
References
1. G. Lippmann, C. R. Acad. Sci., 146, 451, (1908).
2. J-S. Jang and F. Jin, Opt. Lett, 28, 1421-1423, (2003).
3. Q. Huynh-Thu, M. Ghanbari, Electronics Letters, 44, 800-801, (2008)

DHIP 201723

p20-11

J. Yu

Multiple projection 3D display on diffusive fog screen
Jiman Yu, Minwoo Jung, Daerak Heo, Geunseop Choi, and Joonku Hahn
School of Electronics Engineering, Kyungpook National University, Buk-Gu Sankyuk-Dong, Daegu 702-701,
South Korea
Tel.:82-2-950-5514, E-mail: jhahn@knu.ac.kr

1

OCIS codes: (100.6890) Three-dimensional image processing; (220.2740) Geometric optical design; (110.2990)
Image formation theory;

The multi-view displays have been studied in many ways due to their various configuration choices and highquality three-dimensional(3D) contents. Fog display has two advantages to be applied to multi-view display[1].
First, the fog screen is easy to change its form and it is possible for real objects to pass through the screen. Second,
the fog screen functions as the diffusive screen and it fills in the vacant dark region between the two adjacentviews. Therefore, dreamy 3D contents can be demonstrated on the fog screen, but there is a disadvantage thatobservers watch unclear images. In this paper, we improved our previous work by introducing viewing window
technology and making density of fog uniform[2]. So, observers can watch high-definition 3D contents with large
field of view on table-top.

Fig. 1. Schematic of multiple projection 3D display on diffusive fog screen
Figure 1 shows the schematic of our system. It is divided into two main parts, the fog screen and elemental
projection units(EPU). In the fog screen part, a cylindrical pipe is positioned at the center of the table and it
delivers fog from a fog generator. Air curtain surrounding the fog screen helps the fog maintain straight upward
uniformly. Twelve projectors are positioned under the top of the table with the same interval in azimuth angle. A
fresnel lense aligned in front of the each projector reduces the distortion of the image plane and cross-talk.
Moreover, it helps projector’s numerical apertures much larger than those of the conventional projectors.
Acknowledgment
This work was supported by Giga KOREA project, [GK13D0100, Development of Telecommunications terminal
with Digital Holographic Table-top Display]
References
1. A. Yahi, M. Imura, Y. Kuroda, and O. Oshiro, “360-degree fog projection interactive display,” ACM SIGGAPH
Asia 2011 Emerging Technologies, No. 19 (2011).
2. J. Yu, J. Seok, J. Yun, C. Park, H. Jeon and J. Hahn, “Table-top multi-view fog display based on viewing
window technology” IMID2016, Jeju, Korea, Aug. 2016.

DHIP 201724p20-12

E. Dashdavaa

Complex object wave extraction using time-multiplexing in off-axis digitalholography
Erkhembaatar Dashdavaa, Munkh-Uchral Erdenebat, Nyamsuren Darkhanbaatar, Anar Khuderchuluun, and
Nam Kim*1
School of Information and Communication Engineering, Chungbuk National University, Cheongju, Chungbuk
28644, Korea
Tel.:82-43-267-9957, E-mail: namkim@chungbuk.ac.kr
OCIS codes: (090.1995) Digital Holography; (100.6890) Three-dimensional image processing; (090.1760)
Computer holography

In off-axis digital holography as with conventional digital holography, the reconstructed image contains a zeroorder of diffraction which is transmitted background intensity and two twin or conjugate images called the virtualand real images. The zero-order term and twin images can be separated from the reconstructed image using off-axis
recording geometry proposed by Leith and Upatnieks [1-2]. Even if the three parts appear at the different locationsin the reconstructed images, the elimination of these undesired terms is necessary to increase the recordable
bandwidth of the object, thereby improving the image quality of the reconstructed image.
In this paper, we propose a digital method to suppress the zero-order image in off-axis digital holography. Firstly,
the proposed approach utilizes digital time-multiplexing technique, in which 90-degree rotated two off-axis
holograms are recorded in sequence and corresponding spectrums are subtracted in the computed Fourier domain
to eliminate the DC term. Then two subtracted holograms are digitally multiplexed into one complex hologram in
the same plane and by shifting the spatial frequency spectrums of the subtracted hologram in the spatial frequency
domain, one of the two cross-correlations can be obtained in the center as shown in Fig. 1.

Fig. 1. Reconstruction steps of the proposed approach
Acknowledgment
This work was supported by Institute for Information & communications Technology Promotion (IITP) grant
funded by the Korea government (No.2017-0-00417, Openholo library technology development for digitalholographic contents and simulation). This research was supported by the Korea government, under the ITRC
(Information Technology Research Center) support program (IITP-2017-2015-0-00448) supervised by the IITP
(Institute for Information & communications Technology Promotion).
References
1. E. N. Leith, and J. Upatnieks, J. Opt. Soc. Am. 52, 1123 (1962).
2. I. Yamaguchi, and T. Zhong, Opt. Lett. 22, 1268 (1997).

DHIP 201725

p20-13Y. Zhao

Fast calculation method for full-color holographic system of real existing objects
Yu Zhao1, Ki-Chul Kwon1, Seok-Hee Jeon2, Sang-Keun Gil3, Nam Kim1*
School of Information and Commu. Eng., Chungbuk Univ., Cheongju, Chungbuk 361-763, Korea
2
Department of Electronics Eng., Incheon National University, 119 Academic-ro, Yeonsu-gu, Incheon 22012,
Korea
3
Department of Electronics Eng., Suwon University. San 2-2 Wau-ri, Bongdam-eup, Hwaseong-si,Gyeonggido,Korea
1Tel.:82-43-261-2482, E-mail: namkim@chungbuk.ac.kr
OCIS codes: (100.6890) Three-dimensional image processing; (090.1760) Computer holography
With the development of computing technologies over the past decades, optical holography can be totally
through a digital processing method. CGH has significant benefits [1] including that a hologram of a physicalobject can be created quickly. Over the past decade, a lot of research based on the CGH technique has been
proposed, among them, real object-based methods are very popular [2].
In this paper, we propose a full-color polygon-based holographic system for real 3D objects captured by a depth
camera. Our proposed method consists of three steps. In the first step, the point cloud produce by a depth camera
usually has a lot of depth information, The depth and color data of the real scene are acquired simultaneously
through a depth camera connected with a personal computer (PC), where the depth camera consists of a redgreen-blue (RGB) sensor that detects the color, and an infra-red (IR) sensor to detect depth data. The second stepis to classify each point into sub-layers according to depth information. In the third step, each point of the point
cloud can be distributed accurately according to the exact coordinates of each layer in a generated grid, and we
obtain a CGH by executing the diffraction calculation on the sub grids using FFT techniques.

(a)

(b)

(c)

(d)

(e)

Fig. 1. (a) Real 3D object ,(b) point cloud model , numerical reconstructed images focus on the (b) first toy
and (c)second toy, optical reconstructed images focus on the (d) first toy and (e)second toy

toys

Table 1. Generation time for 1,024 × 1,024 holograms (seconds)
Conventional algorithm Conventional algorithm Proposed method
Proposed method
(CPU)
(GPU)
(CPU)
(GPU)
827.06
60.17
24.55
0.68

In this research, we propose a gridding method to generate holograms for real objects captured with a depth
camera. We show that this method can accelerate the generation of the hologram. The numerical and experimental
results both indicate that real 3D objects can be reconstructed clearly. The authors believe that this method will be
useful for creating CGHs for a real-time full-color holographic display.
Acknowledgment
This work was supported by Institute for Information & communications Technology Promotion(IITP) grant
funded by the Korea government (No.2017-0-00417, Openholo library technology development for digitalholographic contents and simulation). This research was supported by the Korea government, under the ITRC
(Information Technology Research Center) support program (IITP-2017-2015-0-00448) supervised by the IITP
(Institute for Information & communications Technology Promotion).
1.
2.

References
A. W. Lohman and D. P. Paris, “Binary Fraunhofer holograms generated by computer,” Appl. Opt. 6, 1739
(1967).
Y. Zhao, K. C. Kwon ,Y. L. Piao ,S. H. Jeon, and N. Kim, "Depth-layer weighted prediction method for afull-color polygon-based holographic system with real objects." Optics Letters (42.13),2599-2602.(2017)

DHIP 201726

p20-14

H. -D. Jeong

A refractive index sensor based on an extraordinary optical transmission in a
floated metal nano-slit array
Hee-Dong Jeong1, Yong-Sang Ryu2 and Seung-Yeol Lee1*
School of Electronics Engineering, Kyungpook National University, Bukgu, Daegu 702-701, Republic of Korea
2
Sensor System Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
Tel.:82-53-950-6608, E-mail: seungyeol@knu.ac.kr

1

OCIS codes: (240.6680) Surface plasmons; (280.4788) Optical sensing and sensors; (310.6628) Subwavelength
structures, nanostructures
The surface plasmon polaritons (SPPs) are surface electromagnetic waves propagating along the plane interface
between metal and dielectric [1]. SPPs has been applied to various optical devices such as waveguides, near-field
optics, optical data storage, solar cells, and surface-enhanced Raman scattering (SERS) based optical sensors
because it can confine light into sub-wavelength scale and overcome diffraction limit.
SPPs attracted the attention of scientists since the work of the Ebbesen’s research group has been reported in
1998. They found that the transmission of light through Ag or Au films with nanohole arrays can be dramaticallyincreased compared to the amount they predicted [2]. This phenomenon, called extraordinary optical transmission(EOT), can improve the sensing performance of the sensor system. Especially, as the sensing area of the nanoholeand nano-slit structure becomes smaller, it can be used in biosensors, chemical sensors, etc. Also, refractive index
sensing is possible by using the characteristic of EOT that the resonant wavelength of EOT depends on therefractive index of the surrounding environment [3]. In this study, we propose a floated nanoslit array structure forhigh-performance refractive index (RI) sensors based on an EOT.

Fig. 1. (a) A floated RI sensor structure. (b) Simulated transmission spectra of floated RI sensor withsensing material of n = 1.0, 1.3, and 1.5.
Figure 1(a) shows a cross-sectional view of the proposed structure. First, we simulated the optimal conditions of
the EOT generated in our structure using a rigorous coupled-wave analysis (RCWA) method. Based on the
numerical results, CYTOP was spin-coated on a SiO2 substrate with a thickness of 500 nm (TCy), and Au wasdeposited on the CYTOP with a thickness of 350 nm (TAu). After that, a metal was patterned with period (P) of
650 nm and width (W) of 350 nm using focused ion beam (FIB) process. Then, etching of the CYTOP under thenanoslit pattern is done for design a tunable RI sensor structure. We can freely tune the resonant condition of EOT
by filling a space under the pattern with a various refractive indexes. Figure 1(b) shows the result of index tuning
simulation of the proposed structure. Each of the graphs was obtained by simulating a material with refractive
index of 1.0 (air), 1.3, and 1.5 under the pattern, and a transmittance close to 0.8 was obtained.
Acknowledgment
This work is supported by the National Research Foundation of Korea and the Ministry of Science and ICT (NRF2017R1C1B2003585).
References
1. S. A. Maier, Plasmonics : Fundamentals and Applications (springer-Verlag, New York, 2007).
2. T. W. Ebbesen, H. J. Lezec, H. F. Ghaemi, T. Thio, and P. A. Wolff, Nature, 391, 667 (1998).
3. R. Gordon, D. Sinton, K. L. Kavanagh, and A. G. Brolo, Accounts of chemical research, 41, 1049 (2008).

DHIP 201727

p20-15

Y. BaeAnalysis on random plasmonic nanopillar structureusing Bruggeman effective medium theory
Youngkyu Bae1, Yong-Sang Ryu2, and Seung-Yeol Lee1*
School of Electronics Engineering, Kyungpook National University, Bukgu, Daegu 702-701, Republic of Korea
2
Sensor System Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
Tel.:82-53-950-6608, E-mail: seungyeol@knu.ac.kr

1

OCIS codes: (240.6680) Surface plasmons; (280.4788) Optical sensing and sensors; (310.6628) Subwavelength
structures, nanostructures
Due to the improvement of recent nano-fabrication technology, various sensing devices using surface plasmon
polaritons (SPPs) have been developed recently [1]. Mostly, these subwavelength-scale devices have been utilizedwith a periodic structure. However, fabrication of periodic structure often needs high costs when they are executedin a large-scale. In order to cope with this problem, it has been attempted to adopting an irregular structure,deviating from the regularity of devices. Unfortunately, to fully compute the electromagnetic characteristics ofthese irregular structures with a well-known EM-wave analysis methods such as finite-difference time-domain(FDTD) method, it involves significant error unless perfectly expressing all of random nature of the irregularstructure, which significantly wastes computation time and memory. Therefore, it is necessary to have a different
interpretation modeling for these kinds of structures. In this presentation, we apply an Bruggeman effective
medium theory (BEMT) as one of the solutions to analyze random plasmonic nanopillar geometry [2].

Fig. 1. (a) A schematic of plasmonic nanopillar structure that used in experiment. (b) A simplified structureusing BEMT on Cytop layer. (c) Reflection spectra of proposed structure using BEMT.
BEMT provides a mixed permittivity taking into account the mutual electromagnetic effects of a mixture ofdielectric and metal in the microscopic nature of the subwavelength scale. We used this mixed permittivity to
predict the reflection spectra of EM waves in a plasmonic nanopillar geometry that is randomly mixed with metaland dielectric medium as shown in Fig. 1, which was also experimentally compared.
The calculated nanopillar structure has 4 layers, which are randomly distributed Au nano-island (30nm), Cytop
nanopillar (164nm), flat Au (100nm) and SiO2 substrate from top to bottom. The top and second layer are
randomly distributed by thermal evaporating and etching, respectively. Changing the filling factor of the Cytop
layer to 100%, 87%, 51% and 13%, we simulated the reflectance of device at visible spectrum and compared withexperimental results which showed satisfactory similarity by using the permittivity obtained from BEMT. We
expected that BEMT modeling will be used in various ways in a irregular large-scale plasmonic sensor devices.
Acknowledgment
This work is supported by the National Research Foundation of Korea and the Ministry of Science and ICT(NRF-2017R1C1B2003585).
References
1. S. A. Maier, Plasmonics : Fundamentals and Applications (springer-Verlag, New York, 2007).
2. W. Cai and V. Shalaev, Optical Metamaterials : Fundamentals and Applications (Springer, New York, 2009)

DHIP 201728

p20-16

S. -Y. Park

Fabrication of camera lens using photopolymer
Seo-Yeon Park, Jae-Min Lee, Chang-Won Shin, Hui-Ying Wu, and Nam Kim*
School of Information and Communication Engineering, Chungbuk National University, Cheongju,
Chungbuk 28644, South Korea
Tel.:82-043-276-9957, E-mail: *namkim@chungbuk.ac.kr
OCIS codes: (090.2890) Holographic optical element; (040.1490) Cameras; (220.0220) Optical design andfabrication

Recently, the Holographic optical element (HOE) has become a promising field in the holography. Two coherent
beams are encountered as the principle of HOE and the interference is generated by the phase difference. The
HOE is a diffractive optical element which is widely used because of its advantages such as thin, easy mass
production, and complex functions. Photopolymer, dichromated gelatin, silver-halide emulsion, photoresist arecommonly used recording material for HOE. Amongst them, the photopolymer is a nonlinear holographic
recording material which is suitable for volume phase hologram.
The camera lens is an optical lens which transmits light to a film or image sensor. It is usually used in the formof a multi-lens, in which multiple lenses are superimposed rather than a single lens. Therefore, a multi-lens has the
disadvantage that the camera device becomes bulky. To overcome these disadvantages, we propose a method toreplace multiple lenses with photopolymer.

(a)

(b)

Fig 1. (a) Experimental setup for recording Camera lens HOE (b) result
The recording setup of the multi-lens HOE is shown in Fig 1(a). The wavelength of the laser was 532 nm. The
camera lens with a focal length of 55 mm has been recorded at 30 degrees with a symmetrical transmission typestructure in the photopolymer.
The experimental results are shown in Fig. 1(b). It is expected that this method will contribute to solving thebulky camera lens issues and also it will be adapted with smartphones or cameras.
Acknowledgment
This work was supported by Institute for Information & communications Technology Promotion(IITP) grant
funded by the Korea government(No.2017-0-00417, Openholo library technology development for digitalholographic contents and simulation). This research was supported by the Korea government, under the ITRC
(Information Technology Research Center) support program (IITP-2017-2015-0-00448) supervised by the IITP
(Institute for Information & communications Technology Promotion)
References
1. Y. M. Kim, B. Song, S.-W. Min, Opt Lett, 39(1), 105(2014).
2. J.-A. Piao, G. Li, M.-L. Piao, N. Kim, J. Opt. Soc. Korea, 242-248(2013).

DHIP 201729

p20-17

K. KimUniversal light engine with three digital micromirror devices
Kwangsoo Kim, Geunseop Choi, Daerak Heo, and Joonku Hahn
School of Electronics Engineering, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu 41566,
South Korea
Tel.:82-53-950-5514, E-mail: jhahn@knu.ac.kr
OCIS codes: (110.0110) Imaging system; (220.0220) Optical design and fabrication; (230.0230) Optical devices.

Digital micromirror device (DMD) has a great potential as a high-speed driving decive for time-multiplexing 3D
display. In recent years, 3D displays using the DMD have been actively studied by many researchers. We also
have developed several 3D systems such as super multi-view display, cylindrical display, table top display, andcrystal-ball display [1-4]. There is a growing demand for a universal light engines in 3D displays, but theuniversal light engine using the DMDs have not yet been developed. We suggest a universal light engine that canbe used for various full-color 3D display systems. Figure 1 shows a system diagram with a universal light engine.
The light engine designed to be available for various systems so it is possible to be used with one light engine
design. In the light engine, we designed our own opto-mechanical adjusts for optics and it is easy to physicallyalign the three DMDs. This system uses an LED light source, and each system can be attached to and detachedfrom various systems with a single light engine using an adapter lens.

Fig. 1. System diagram with a universal light engine.
Acknowledgment
This work was supported by GigaKOREA project, [GK GK13D0100, Development of Telecommunications
Terminal with Digital Holographic Table-top Display] and by Samsung Research Funding Center of Samsung
Electronics under Project Number SRFC-IT1301-07.
References
1. C. Lee, S. Lim, H. Jeon, and J. Hahn, “Super multi-view display for analyzing human cognition,” Proc. SPIE
9770, paper 9970-06 (2016).
2. K. Kim, S. Lim, H. Kim, and J. Hahn, “Full-color Tabletop Light-field Display,” in Imaging and Applied Optics
2016, OSA Technical Digest, DT4D.5 (2016).
3. G. Choi, H. Jeon, H. Kim, and J. Hahn, “Cylindrical directional display with multiple spinning slits,” The 16th
International Meeting on Information Display, Jeju, P2-65 (2016).
4. Y. Lim, K. Hong, H. Kim, H.-E. Kim, E.-Y. Chang, S. Lee, T. Kim, J. Nam, H.-G. Choo, J. Kim, and J. Hahn,“360-degree tabletop electronic holographic display,” Opt. Express 24, 24999-25009 (2016).

DHIP 201730

p20-18

D. HeoSpherical light field display
Daerak Heo, Mugeon Kim and Joonku Hahn*
School of Electronics Engineering, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu, South Korea
Tel.:82-53-951-5514, E-mail: jhahn@knu.ac.kr
OCIS codes: (100.6890) Three-dimensional image processing; (120.5800) Scanners.
There have been many researches on three-dimensional(3D) display[1]. Various geometrical shapes of 3D displays
have been suggested. Among them, 3D display with spherical symmetry is very interesting since it has a potential
to provide 360-degree field of view. Only few studies on spherical 3D display have been reported and a crystal ballis applied to allow multiviews through its center[2]. But some practical problems such as alignment and maintenancemay results from a large number of depth fused display units. One simple strategy to solve these problems is toreplace space-division multiplexing with time-division multiplexing. For time-division multiplexing, a digital
micromirror device(DMD) is usually used due to its driving speed[3].

Fig. 1. Spherical light field display.
Figure 1 shows a schematic of our system and 3D contents appear in a crystal ball. Our system is composed of alight engine, magnification lenses, two scanners, two relay lenses and a crystal ball. The image is generated by thelight engine in high speed and 4f magnification lens delivers the image to the resonant scanner. After that, the firstrelay lens forms a conjugate plane of the resonant scanner at the galvanometer. Finally, the second relay lens forms
an image plane inside of the crystal ball. The direction of views are controlled by two scanners and every view
passes through the center of the crystal ball. Therefore, we observe 3D contents at the inside of the crystal ball withlarge field of view.
Acknowledgment
This work was supported by Samsung Research Funding Center of Samsung Electronics under Project Number
SRFC-IT1301-07
References
1. J. Hong, Y. Kim, H.-J. Choi, J. Hahn, J.-H. Park, H. Kim, S.-W. Min, N. Chen, and B. Lee, “Three-dimensional
display technologies of recent interest: principles, status, and issues,” Appl. Opt. 50, H87-H115 (2011).
2. M. Date, T. Kawakami, M. Sasai, and H. Takada, “Screen-free floating 3D image in a crystal ball using spatiallyimaged iris and multiview DFD(depth fused 3D) technologies,” SID’16 Digest 47, 146 (1984).
3. Y. Lim, K. Hong, H. Kim, H. Kim, E. Chang, S. Lee, T. Kim, J. Nam, H. Choo, J. Kim, and J. Hahn, “360-degreetabletop electronic holographic display,” Opt. Express 24, 24999-25009 (2016).

DHIP 201731p20-19

S. LimTime-sequential super multi-view display
Sungjin Lim, Geunseop Choi, Mugeon Kim, Kwangsoo Kim and Joonku Hahn*
School of Electronics Engineering, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu 41566, South
Korea
Tel.:82-53-950-5514, E-mail: jhahn@knu.ac.kr
OCIS codes: (100.6890) Three-dimensional image processing; (090.1760) Display; (220.2740) Geometric opticaldesign;Three-dimensional (3D) display technologies have been regarded as one of the most popular issues and many
researchers have tried various approaches to improve the quality of 3D display [1-3]. One of the approaches is asuper multi-view (SMV) display and the SMV display has an advantage of reducing 3D sickness caused by thevergence-accommodation conflict since more than two views enter the pupil of the eye. We invented a SMV
display which is able to change the number of views entering the pupil and our system is expected to clarify theprinciple of human cognition on 3D object [4].

Fig. 1. Time-sequential super multi-view display.
In this paper, we improve our previous work on SMV display. Figure 1 shows a schematic of time-sequential
SMV display. The system consists of the projection part and the observation part. The projection part isconfigured by the light engine which realize full-color images by using three digital micro-mirror devices. The
projected image at the screen is observed through the observation part which has the optical system. The opticalsystem consists of two lenses and an optical chopper between the lenses for defining the direction of the image
entered into eyes.
Acknowledgment
This work was supported by Samsung Research Funding Center of Samsung Electronics under Project Number
SRFC-IT1301-07.
References
1. J. Hong, Y. Kim, H.-J. Choi, J. Hahn, J.-H. Park, H. Kim, S.-W. Min, N. Chen, and B. Lee, “Three-dimensional
display technologies of recent interest: principles, status, and issues,” Appl. Opt. 50, H87-H115 (2011).
2. N.S. Holliman, N.A. Dodgson, G.E. Favalora, and L. Pockett, “Three-Dimensional Displays: A Review andApplications Analysis,” IEEE Trans. Broadcast. 57, 362-371 (2011).
3. Y. Takaki, “Super Multi-View Display and Holographic Display,” The 22nd Annual Meeting of the IEEE
Photonics Society (LEOS), Belek-Antalya, Turkey (2009).
4. C. Lee, S. Lim, H. Jeon, and J. Hahn, “Super multi-view system for analyzing human cognition,” Pro. SPIE
9770, 9970-06 (2016).

DHIP 201732

p20-20

G. Choi

Cylindrical light field display
Geunseop Choi1, Hosung Jeon1, Kwangsoo Kim1, Hwi Kim2 and Joonku Hahn1
1
School of Electronics Engineering, Kyungpook National University, 80, Daehak-ro, Buk-gu, Daegu, 41566,
South Korea
Tel.:82-53-950-5514, E-mail: jhahn@knu.ac.kr
2
Department of Electronics and Information Engineering, Korea University, Sejong Campus, Sejong-ro, 2511,
Sejong 30019, South Korea
OCIS codes: (100.6890) Three-dimensional image processing; (230.6120) Spatial light modulators; (220.4830)
Systems design

The light field display is the most natural three-dimensional(3D) display considering the visual perception factor.
For this reason, various light field displays have been suggested in both industry and academy. We proposed acylindrical light field display with rotating slits in last year[1]. Cylindrical shape has interesting advantages inproviding 360-degree field of view and rotating the structure[2]. Until now, many systems providing 360-degree
field of view have been realized by using multiplexing techniques. Some of them are implemented with pluralprojectors surrounding the screen. Others are implemented with a high-speed projector and the optics including ascreen is usually rotating. In this paper, we propose a cylindrical light field display and it has two significant
advantages. First, three digital micromirror device(DMD)s are used as a high-speed projector and it lessens theefforts for alignment of plural projectors. Second, the optics are also designed to have cylindrical symmetry and it
is possible to let the optics stationary.

Fig. 1. Cylindrical light field display.
Figure 1 shows a schematic of cylindrical light field display. The image on the DMDs is projected upward along
the axis of rotation and the light is reflected by the convex mirror at the top of the cylinder. Then, the image is
projected on the rotating cylindrical screen. The observer watch 3D contents inside of the cylinder through theslits on the surface.
Acknowledgment
This work was supported by Samsung Future Technology Fund of Samsung Electronics Inc. under Grant Number
SRFC-IT1301-07.
References
1. G. Choi, H. Jeon, H. Kim and J.Hahn, “Cylindrical directional display with nultiple spining slits,” The 16th
International Meeting on Information Display, Jaeju, Korea, P2-64, Aug. 2016
2. T. Yendo, N. Kawakami, and S. Tachi, “Seelinder: The Cylindrical Lightﬁeld Display,” in Proceedings of ACM
SIGGRAPH emerging technologies (ACM, 2005) Article 16.

DHIP 201733

p20-21

Y. -L. Piao

Orthographic projection based holography with low density modeling pointcloud
Yan-Ling Piao1, Alam MD Shahinur1 Jong-Rae Jeong2 and Nam Kim1*
1
Dept. of Electrical & Computer Engineering, Chungbuk National University, Korea
Tel.:82-43-9957, E-mail: namkim@chungbuk.ac.kr
2
Dept. of Information and Communication, Suwon Science College, Korea
OCIS codes: (110.6880) Three-dimensional image acquisition; (100.6890) Three-dimensional image processing;(090.1760) Computer holography
Hologram generation methods can be classified depending on the type of input data: synthetic 3D scenes or multiview data. Hologram computation from multi-view data have two approaches: the multi-viewpoint projection
based methods and the holographic stereogram approach. With development of the science and technology, thedevice which extracted 3d information of real-existing scenes is improved such as depth camera, light fieldcamera, etc. However, the extracted 3d information is not enough to describing the realistic scenes for generating
synthetic hologram by usual synthetic model (point cloud, polygon, etc). It is possible to use multi-view data. But
it is also challenging to provide all the human depth cues and accurate shading of the scene with only a few
projection images. In order to improve the quality of CGH, we generate the multi-view image and depth
information for synthetic CGH using low density point cloud which is modelling by 3D scan with depth camera.

Fig. 1. Generated orthographic images by low density point cloudIn this paper, we proposed a computer-generated hologram system of a real-existing scene by depth camera using
orthographic projection based images and depth map. Real scene captured by depth camera in 3d scanning mode,
then the point cloud model and corresponding color information is processed to generating orthographic
projection images and depth map. Hidden point remove was used in point cloud to orthographic projection image(and depth map) conversion. And the hole filling method will be used. Finally, the orthographic projection images
and depth map will be used to compute hologram with low angular sampling.
Acknowledgment
This work was supported by Institute for Information & communications Technology Promotion(IITP) grant
funded by the Korea government (No.2017-0-00417, Openholo library technology development for digitalholographic contents and simulation). This research was supported by the Korea government, under the ITRC
(Information Technology Research Center) support program (IITP-2017-2015-0-00448) supervised by the IITP
(Institute for Information & communications Technology Promotion).
References
1. Y. Ohsawa, Computer-generated holograms using multiview images captured by a small number of sparsely
arranged cameras, Applied Optics, pp. A167-A176, 2013.
2. J. H. Park, Fresnel and fourier hologram generation using orthographic projection image, Optics express Vol. 17,
No. 8, pp. 6320-6334, 2009.
3. T. Mishina, Calculation of holograms from elemental images captured by integral photography, Applied optics.
Vol. 45, No. 17, pp. 4026-4036, 2006.

DHIP 201734

p20-22

S. KimAnalysis of 360-degree Non-mechanical Table Top Electronic Holographic
Display System
Soobin Kim and Hwi Kim
Dept. of Electronics and Information Engineering, Korea University, Sejong 30019, Korea
Tel.: 82-44-860-1736, E-mail: hwikim@korea.ac.kr
OCIS codes: (090.1995) Digital holography; (090.2870) Holographic display; (120.4820) Optical systems

Three-dimensional (3D) holographic displays are considered as the ultimate display and the challenge forresearchers. A table-top holographic display system is an issue and promising candidate for next generation 3D
holographic display system. Recently, the 360-degree holographic table-top display was introduced in Giga Korea
Project which was supported by the Korean Federation of Science and Technology Societies(KOFST). Thissystem consists of digital micromirror device (DMD) for color image representation, 4-f Fourier filtering systems,a parabolic mirror for 3D observation and a mechanical motor for 360-degree images on the viewing
circumference [1]. However, the design of an electronic system which has the mechanical rotary motor has not yet
accomplished, and this problem is remained as a challenge of the system.
In this paper, we carried out analysis and design of non-mechanical table-top type display system based ongeometric and wave optics. Our suggested system consists of multi-sub panel, 4-f system, parabolic mirror, fieldlens and two types of prisms. Multi-sub panel is a high-resolution panel and divided by sub-region. Because of
these sub-regions, the system has more viewpoint. And the incident beams are refracted by each prism [2].

(a)(b)
Fig. 1. (a) Schematic diagram of proposed system, and (b) result of simulation based on geometric optics
The schematic diagram shown in Fig. 1. (a) is designed for the proposed system. It consists of 32 by 32 region
panel, resolution of each sub-panel is 256 by 256, and two types of prisms. The fig. 1 (b) shows the result of
simulation based on geometric optics for proposed system. The final goal of this research is design of RGB fullcolor system increasing of viewpoints to 1,024.
Acknowledgment
This work was supported by GigaKOREA Project (GK17D0100, Development of Telecommunications Terminal
with Digital Holographic Tabletop Display).
References
1. Y. Lim, K. Hong, H. Kim, H.-E. Kim, E.-Y. Chang, S. Lee, et al., "360-degree tabletop electronic holographic
display," Opt. Express 24, 24999-25009 (2016).
2. Marios Papas, Thomas Houit, Derek Nowrouzezahrai, Markus Gross, Wojciech Jarosz. The Magic Lens:
Refractive Steganography. ACM Transactions on Graphics (Proceedings of SIGGRAPH Asia), 31(6),November 2012.

DHIP 201735

p20-23

J. B. Choi

Geometrical optical modeling and diffraction efficiency analysis of diffractive
augmented reality system
JungBeom Choi, JongHa Park, SooBin Kim, and Hwi Kim
Dept. of Electronics and Information Engineering, Korea University, Sejong 30019, Korea
Tel.:82-44-860-1736, E-mail: hwikim@korea.ac.kr
OCIS codes: (090.2820) Heads-up displays; (050.1950) Diffraction gratings; (120.4820) Optical systems;
Augmented Reality (AR) is the significant technology of head-mounted-display (HMD) which is one of thenext-generation displays, and has received great attention in recent years. Accordingly, Microsoft HoloLens is at
the forefront of augmented reality technologies that is commonly used with diffractive optical elements. However,further research for the Microsoft HoloLens is needed because it has achieved high performance through a thincombiner without using a lens. In this paper, we show the numerical model based on the electromagnetic analysis
with the accurate structural design of the combiner of the diffractive optical element, which is implemented in thediffractive AR system.

Fig. 1. Geometrical optical modeling and diffraction efficiency ratio
Fig. 1. (a) shows the simulation of geometrical optical modeling for a combining system of the diffractive AR.
When light passes through the input grating structure, the diffraction is occurred in the direction of the expanded
grating structure. In this diffracted light, the next diffraction is occurred in the direction of the output lattice
structure by the expanded lattice structure, and it is replicated at the same time. This replicated light continues todiffract and replicate continuously by the expansion grating structure, and the incident light on the output grating
structure is output in a parallel direction to the input light. These processes allow we could duplicated one light tomultitude of lights, which is forming a field of view (FOV).
The diffraction efficiency distributions of the expander and output gratings obtained by simple calculation
theory as shown in Fig. 1 (b). The gratings with these efficiencies could be designed using Fourier Modal Method(FMM) and could be applied to the expander and output gratings that has a final goal of uniform light efficiency.
If the light efficiency is uniform, an image in the retina is clearly formed when the light beam from the output
grating is entering to the eye. [1].
In this paper, we carried out the analysis of the optical structure for a diffractive AR by hybrid modeling ofgeometrical optics and electromagnetic field analysis as described above, and ultimately propose a new opticalstructure to improve yield of the grating process, FOV and light emitting efficiency.
Acknowledgment
References
1. H. Kim and B. Lee, "Rigorous Fourier modal analysis on slab structures with finite thickness and onedimensional arbitrary permittivity and permeability profiles," The 11th Micro-optics Conference Tokyo, Japan,
Oct.-Nov. 2005.

DHIP 201736

p20-24

S. Park

Fast Calculation Method of High-Definition Computer-Generated Hologram
Sungjae Park, Jonghyun Lee and Hwi Kim*
Department of Electronics and Information Engineering, Korea University, Sejong 30019, Korea
Tel.:82-44-860-1428, E-mail: hwikim@korea.ac.kr
OCIS codes: (090.2870) Holographic display; (090.1760) Computer holography; (090.1705) Color holography

High-definition (HD) computer-generated hologram (CGH) has been actively researched because it can solve theproblems of holographic 3D display that narrow viewing angle and limited resolution [1-2]. Also it can display
realistic and high quality holographic 3D images. HD CGH is a large scale that requires huge computational timeand great memory, so the enhancement in efficiency of computation algorithm is important issue [3]. In this paper,
we proposed a method to calculate the large scale of HD CGH by the localized light wave computation of polygon
mesh and the viewing zone division technique.
As a first method, a conceptual diagram and mathematical formula of segmentation method for large-scale CGH
calculation are shown in Fig. 1. (a). The second method is the local polygon calculation as shown in Fig. 1(b). Our
proposed method that ultimate final solution is to calculate CGH by hybridization of these two techniques. The
first step of this technique is to divide and calculate in the viewing zone. The second step is localized calculationof angular spectrum of the polygon mesh for the segmented area. This step calculates only some areas dependingon the polygon size, unlike the traditional method of calculating the entire area for calculating one polygon.
Finally, the locally computed small fields are stamped on their original large field, respectively. This procedure
improves memory efficiency and enables fast HD CGH calculations.
(b)

(a)





CGH total   exp j  k m,n, x x  k m,n, y y  k m,n, z z  Fm,n x, y mLocalized calculation

Stamp

n

Fig. 1. Conceptual diagram of (a) viewing zone segmentation method and (b) localized polygon calculation
The proposed method can efficiently calculate HD CGH and is useful for many applications. Our future work is
to calculate a 160K by 160K full color HD CGH and build a system for the practical CGH content generation
process.
Acknowledgment
This work was supported by the Industrial Strategic technology development program (10052641, Developmentof the commercialization platform technology for diffractive optical element based on 3D surface nanostructure
for full-color implementation) funded by the Ministry of Trade, industry & Energy (MI, Korea).
References
1. Y. Tsuchiyama, K. Matsushima, S. Nakahara, and Y. Sakamoto, "Full-Color High-Definition CGH Using Color
Filter and Filter Design Based on Simulation," in Imaging and Applied Optics 2016, OSA Technical Digest(online) (Optical Society of America, 2016), paper DW5I.4.
2. K. Matsushima and S. Nakahara, "Extremely high-definition fullparallax computer-generated hologram createdby the poly-gon-based method," Applied optics 48, H54-H63 (2009).
3. J. Cho, J. Hahn, and H. Kim, "Fast reconfiguration algorithm of computer generated holograms for adaptive
view direction change in holographic three-dimensional display," Optics Express 20, pp. 28282-28291, (2012).

DHIP 201737

p20-25

J. Park

Analysis of Moiré Deflectometry in Display System using Talbot EffectJunghwan Park and Hwi Kim
Dept. of Electronics and Information Engineering, Korea University, Sejong 30019, Korea
Tel.: 82-44-860-1736, E-mail: hwikim@korea.ac.kr
OCIS codes: (120.4120) Moire’ techniques; (070.6760); Talbot and self-imaging effects; (090.1760) Computer
holography

When the display system is manufactured, various optical functional panels are integrated inside of two glasses.
In the combination of panels between two sheets of glasses, because of complicated optical interactions, accuratealignment is the crucial key point for the appropriate result. In this paper, the simulation was carried out for
generating Moiré patterns using Talbot effect, and analyzing the generated Moiré pattern to confirm that thepanels are properly bonded. Through this process, we can measure the displacement, rotation angle [1], and tilt
angle between upper and lower plates.

(a)

(b)
(c)
Fig. 1. (a) Schematic of simulation, (b) Simulated Talbot pattern,(c) Results of Moiré patternFig. 1. (a) shows the basic schematic of simulation assuming that the upper plate is tilted as much as  . The 1storder Talbot pattern by the grating structure of the lower plate occurs on the grating of the upper plate, and the
Moiré pattern is generated by this 1st Talbot pattern on the upper grating. In the simulation result in Fig 1. (b), we
can see the Talbot pattern by the grating of lower plate. The Talbot distance is adjustable by regulating the grating
period in this system [2]. The incident angle  is 10 degree and the medium is composed of free space and glass.
Finally, the simulated Moiré pattern is shown in Fig 1.(c). It is occured by interference of upper grating andTalbot pattern of lower grating. As a conclusion, we can determine the tilt angle  of upper and lower plates byanalyzing the Moiré pattern in Fourier domain.
Acknowledgment
This work was supported by LG display Co. LTD.
References
1. B.J. Kim, K.C. Yuk, S.I. Lee, S. Chang, "Use of a phase type elongated circular grating in Talbot moiré
deflectometry", In Optik - International Journal for Light and Electron Optics, Volume 115, Issue 3, Pages
121-128, (2004)
2. Yoshiaki Nakano and Kazumi Murata, "Measurements of phase objects using the Talbot effect and moiré
techniques," Appl. Opt. 23, 2296-2299 (1984)

DHIP 201738

p20-26

J. H. Park

Localization Method of Depth-map Computer Generated Hologram for Fast
Calculation
JongHa Park, JiSung Yoon, SungJae Park, JongHyun Lee and Hwi Kim
Department of Electronics and Information Engineering, Korea University, Sejong 30019, Korea
Tel.:82-44-860-1428, E-mail: hwikim@korea.ac.kr
OCIS codes: (090.1760) Computer holography; (050.1970) Diffractive optics;

Real-time CGH calculations is essential for the implementation of HMD type holographic display. As the HMD
industry grew, more research on the technology of generating real-time CGH became necessary. The crucial key
point of depth-map CGH generation which is one of the real-time CGH technology is the cascaded FFT method.
So, it is important to reduce the calculation time of process in cascaded FFT for the fast calculation. In this paper,
we propose the localization method of depth-map CGH for the fast calculation. The first step is area segmentation
as shown in Fig. 1. (a). Generally, the computation amount of depth-map CGH from SLM of N by N resolution is
described as N 2 log2 N 2 . However, the amount from m by m by using area segmentation method is described as
N 2 log2 N 2  log2 m2 . Therefore, the proposed method is much faster than conventional area segmentation

method. The second step is local area calculation method as shown in Fig. 1. (b). When the object with multiple
depth is divided to 2D images with different depth, the images are composed of very sparse images. Thus, the FFT
computation of the entire area of image is a huge waste of computation. Therefore, the depth-map CGH should be
calculated by only the meaningful region of the image for the effective calculation.

(a)(b)
Fig. 1. (a) Schematic of area segmentation method (b) Schematic of local area calculation method
The proposed fast computation algorithm of the depth-map CGH assumes that the same object is created by
CGH with multiple focus. Therefore, the FFT process of propagation from the pupil to the retina have been
performed the same calculation process as different depth CGH which is located at the same distance from the eye.
Consequently, it is not necessary to recalculate CGH when creating other CGH of different depth.
Acknowledgment
This work was supported by Samsung Electronics Co., Ltd.
References
1. T. Senoh, K. Yamamoto, R. Oi, T. Mishina, & M. Okui, Computer generated electronic holography of naturalscene from 2D multi-view images and depth map, In Universal Communication, ISUC’08. Second
International Symposium (2008).

DHIP 201739p20-27

D. LeeComparison of LED and LD as a light source for near-eye holographic display
Dukho Lee, Gang Li, Byounghyo Lee and Byoungho Lee*
School of Electrical and Computer Engineering, Seoul National University, Gwanak-Gu Gwanakro 1, Seoul
151-744, Korea*byoungho@snu.ac.kr
OCIS codes: (090.2870) Holographic display; (090.1995) Digital holography

1. Introduction
Recently, as interest in augmented reality (AR) and virtual reality (VR) increases, the market for head mounted
display is growing. Various research groups and companies are studying on near-eye displays, but it is not enoughto be commercialized yet. The near-eye displays should offer wide viewing angle, fast frame rates, high resolution
images, and small form factors, but the most important factor is to provide more natural 3D images so that users
can watch the display for a long time without visual fatigue [1]. Various approaches using light field techniquehave been studied [2], but there is a fundamental limitation of wavefront approximation. Therefore, ultimately, theholographic display capable of fully reproducing wavefront should be applied to AR and VR systems. However,requirement of high coherence light source such as laser makes it difficult to develop a compact near-eye
holographic display system.
In this paper, we compare light emitting diode (LED) and laser diode (LD) as a light source for near-eye
holographic display to determine which light source is more suitable. To demonstrate better light source selection,
several experiments which reconstruct holograms at different depth planes using the light sources are carried out.
2. Experiment analysis
There are two types of coherence: spatial coherence and temporal coherence. The former one determines theimage contrast which increases as the size of the light source decreases. The latter one determines the depth rangeof holographic display while the high temporal coherency induces severe speckle noise. Thus, there is a trade-off
between depth range and speckle noise in selecting coherence time. It is necessary to decide optimal coherencetime for near-eye holographic display. Fig. 1 shows the coherence time versus spectral width graph of the lightsource. In the experiment, we used LED (Thorlabs, M530F2) and LD (Thorlabs, CPS532) light source shown in
red circle and green circle in Fig. 1. The wavelengths of LED and LD are 530 nm and 532 nm, respectively, andthe bandwidth (FWHM) of each light source is 30 nm and 0.8 nm, respectively. A holographic display systemusing a reflection type spatial light modulator (Jasper Display Corp., JD4704) is implemented as shown in Fig. 2.

Fig. 1. Coherence time of LED and LD

Fig. 2. Experimental setup

DHIP 201740

p20-27

D. LeeFig. 3 shows the reconstruction images corresponding to different depths. Fig. 3(a) shows the case of using
LED, and (b) shows the results of using LD. It is confirmed that the image can be reconstructed up to 170 mm
depth using LED, and the severe speckle noise appear in the region farther than 280 mm using LD. If we combine
an eye piece lens of focal length less than 170 mm and LED, images can be reconstructed from the eye piece lensplane to infinity depth without speckle noise [3].

Fig. 3. Reconstruction images using (a) the LED and (b) the LD light source

3. Conclusion
In this paper, the LED and the LD are used as a light source of holographic display. When an LED light sourcewith coherence length of 50 nm and a wavelength of 530 nm was used, images can be reconstructed up to 170 mm.
In conventional near-eye holographic display system, the focal length of eye piece lens is shorter than 170 mm, so
LED light source could be used for near-eye holographic display.
Acknowledgment
This research was supported by Projects for Research and Development of Police Science and Technology underCenter for Research and Development of Police science and Technology and Korean National Police Agency.
(Grant No. PA-H000001)
References
1. B. Lee, "Three-dimensional displays, past and present," Phys. Today 66(4), 36-41 (2013).
2. S. Lee, C. Jang, S. Moon, J. Cho, and B. Lee, "Additive light field displays: realization of augmented reality
with holographic optical elements," ACM Transactions on Graphics 35(4), 60 (2016).
3. A. Maimone, A. Georgiou, J. S. Kollin, "Holographic near-eye displays for virtual and augmented reality,"
ACM Transactions on Graphics 36(4), 85 (2017).

DHIP 201741

p20-28

B. LeeAugmented-Reality Display for Supporting Ametropia using Maxwellian view
and Edge Enhancement
Byounghyo Lee1, Seungjae Lee1, Dukho Lee1, Hee-Jin Choi2 and Byoungho Lee1,*
School of Electrical and Computer Engineering, Seoul National University, Seoul 151-744, Korea
2
Department of Physics, Sejong University, Seoul 143-747, Korea*
byoungho@snu.ac.kr

1

OCIS codes: (170.0170) Medical optics and biotechnology; (110.6880) Three-dimensional image acquisition;(100.6890) Three-dimensional image processing.

1.

Introduction

There are numbers of people who have the ametropia that an error of refraction occurs since the eye lens fails toform the focused image of objects.With recent rapid improvements in augmented reality (AR) head mounted
display (HMD), some approaches to support the patients by enhancing or correcting the perceived view have been
researched [1, 2]. These prior works, however, do not activly provide focused augmented views as changing theusers focal states since the conventional optical elements in them form virtural image at a fixed depth. In thispaper, we present ametropia supporting AR HMD with an edge enhaced Maxwellian view which forms a focused
image on retinal surface dispite the change of focal states of eye lens.
2.

Principles and demonstration of the proposed method

The entire system is schematized in Fig. 1(a). Our system adopts a Maxwellian view system which consists of alaser projecter, a collimating lens, a waveguide, and a holographic lens as shown in Fig. 1(b). The holograpic lensfunctions as a see-through combiner [3]. After being collimated and guided, the virtual image forms theMaxwellian view through the holographic lens. The Maxwellian view directly projects the virtual image to theretina so that it can make a focused view regardless of focal states of the users. In addition, we process the virtual
image to have higher contrast as enhancing the edge. Fig. 2 shows the experimental results of the proposed system.
Figs. 2(a) and 2(b) indicate the perceived views without and with vision enhancement by the augmented images,
respectivly. We simulate the ametropia as changing the focal length of CCD lens to induce the blur. While thereal-world views are expected to be seen blurred to the ametropia patients, the AR images can support theperception of environmental objects by providing a focused vision-aid images to all type of the patients as shownin Fig. 2(b).

Fig. 1. (a) The entire system of the proposed method. (b) The optical schematic of the proposed AR HMD.

DHIP 201742p20-28

B. LeeFig. 2. Experimental results. The perceived views of ametropic patient as changing the focal
states (a) without and (b) with the proposed AR device.
3.

Conclusion

In this paper, we present an AR device that provides Maxwellian view using holograpic lens. Since theholographic AR device can provide a Maxwellian view to make all in-focus virtual image for low vision aid, ourprototype can support all types of the ametropia patients suffering from the error of refraction. Moreover, it
improves the contrast of AR image by enhancing the edge components of real-world view.
Acknowledgment
This work was supported by Institute for Information & Communications Technology Promotion (IITP) grant
funded by the Korean government (MSIT) (No. 2017-0-00787, Developement of vision assistant HMD andcontents for the legally blind and low visions).
References
1. A. D. Hwang and E. Peli. “Augmented edge enhancement for vision impairment using Google glass,” SID
Symposium Digest of Technical Papers 45, 305-307, (2014).
2. F.-C. Huang et al., “Eyeglasses-free display: towards correcting visual aberrations with computational lightfield displays,” ACM Transactions on Graphics (TOG) 33(4), 59 (2014).
3. S. Lee, B. Lee, J. Cho, C. Jang, J. Kim, B. Lee, “Analysis and implementation of hologram lenses for seethrough head-mounted display,” IEEE Photonics Technology Letters 29(1), 82-85 (2017).

DHIP 201743p20-29

S. AhnApparatus for measuring large field of view embossed hologram
Sunggyun Ahn, Geunseop Choi, Mugeon Kim and Joonku Hahn
School of Electronics Engineering, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu, 41566, South
Korea
Tel.:82-53-950-5514, E-mail: jhahn@knu.ac.kr
OCIS codes: (090.1760) Computer holography; (090.6186) Spectral holography

In recent years, various holograms have been proposed. Among them, nano-structured imprinting hologram is
one of promising hologram in commercial aspect. Since it needs simple manufacturing process, it can be supplied
at low price and be a popular for the public. Then, when we try to measure the hologram, there are some
limitations due to high resolution holograms with the size of 25mm x 25mm and 1μm pixel pitch. A lens with highnumerical aperture and a camera with high resolution are necessary for measurement. To solve this problem, themethod to rotate the camera with telecentric lens was proposed. It operates as a bandpass filter and accept only
narrow bandwidth. Without the high NA lens and the high resolution camera, it is possible to measure thereconstruction images. But, the rotating of observation part may also makes some problems. For example, if alarge scale sample is concerned, the size of lens and observation part will matter and it is difficult to rotate theheavy observation part.
So we propose a new system to rotate the specimen including the light source. The movement of specimen
makes it possible to obtain the angular spectrum of hologram without high NA lens. Furthermore, we can replace
the light source, collimation lens and pinhole. It allows to change the coherence, the divergence and thewavelength of the light source. The spherical bearing is also customized for large rotation angle of the specimen.

Fig. 1. A schematic of apparatus for measuring large field of view embossed hologram
Acknowledgment
This work was supported by the Industrial Strategic technology development program (10052641) funded by
the Ministry of Trade, Industry & Energy (MI, Korea).
References
1. J. Hong, Y. Kim, H.-J. Choi, J. Hahn, J.-H. Park, H. Kim, S.-W. Min, N. Chen, and B. Lee, “Three-dimensional
display technologies of recent interest: principles, status, and issues,” Appl. Opt. 50, H87-H115 (2011).
2. L. Dong, J. Tian, “An accurate calibration method for a camera with telecentric lenses," Optics and Lasers inEngineering 51(5) , 538-541(2013).
3. W. Moon, J. Kwon, H. Kim and J. Hahn, “Electronic holographic device based on macro-pixel with local
coherence,” Proc. SPIE 9626, 51-56 (2015).

DHIP 201744p20-30

H. -E. Kim

Time division multiplexed holographic display using electronic beam steering
methodHyun-Eui Kim1, Min-Sik Park1 and Jinwoong Kim1
Electronics and Telecommunications Research Institute, Korea
E-mail: turnn@etri.re.kr

1

OCIS codes: (909.1995) Digital holography; (090.2970) Holographic display

We propose a time division multiplexed(TDM) holographic display structure with electronic beam steering
method using SLM. The holographic display structure of the TDM scheme is continuously studied by manygroups1,2 as a method of expanding SBP through optical scanner. In this way, the optical scanner is a major
component that greatly affects performance, such as reconstructed image size or viewing angle of the display. In
the conventional TDM method, the mechanical scanning methods of changing the direction of the beam combinedwith the actuator and the mirror were used to achieve the desired result of viewing angle or reconstructed image
size expansion. However, mechanical scanning methods have problems such as mechanical complexity, lowreliability, high power consumption, narrow beam steering area, and phase aberration in the wavefront of a steered
beam. We have solved the disadvantages of the above-mentioned mechanical beam steering system by using
electronic beam steering using SLM.
The beam steering was performed using a phase SLM with a single-dimensional array, and applied to theholographic display structure to extend the horizontal viewing zone. The wrapped phase profile to steer the beamin an arbitrary direction α is derived from φn(α) =2π/λ∙ xn sin α + φ0. Where φn(α) is a wrapped phase profile with
arbitrary steering angle α, xn is the spatial coordinate in the SLM, and φ0 is the arbitrary constant phase offset. λ is
the wavelength of the light source. The obtained phase profile is quantized according to the modulation level of
SLM. Figure 1 is a schematic of a holographic display applying the principle of the proposed method.

Fig. 1. Schematics of proposed holographic display
Acknowledgment
This work was supported by 'The Cross-Ministry Giga KOREA Project' grant funded by the Korea
government(MSIT) (GK17D0100, Development of Telecommunications Terminal with Digital Holographic
Table-top Display)
References
1. H. Kang, et al. Digital Holography and Three-Dimensional Imaging. Optical Society of America, p. DM3E. 5(2016)
2. Y. Takaki, et al. Optics express 24.16 (2016)

DHIP 201745

p20-31

Y. Lim

Improving the image quality of a digital holographic display system by
estimating a virtual spatial light modulator plane
Yongjun Lim, Keehoon Hong, Minsik Park and Jinwoong Kim
5G Giga Communication Research Laboratory, Electronics and Telecommunications Research Institute, 218
Gajeong-ro Yuseong-gu Daejeon 34129, South Korea
Tel.:82-42-860-5984, E-mail: yongjun@etri.re.kr
OCIS codes: (090.0090) Holography; (090.1995) Digital holography

In a general digital holographic display system, it is necessary to filter out unwanted signals given by high-orderdiffraction components and a direct current(DC) component emanating from spatial light modulators(SLMs) whenilluminated by coherent light sources. To achieve this, 4-f optics configuration is conventionally applied, and theimaged plane after passing through the 4-f optics is required to be estimated. In specific, the digital holographic
system fundamentally based on a viewing window depends on the imaged SLM plane, or the virtual SLM plane[1,2]. Here, we are to estimate the virtual SLM plane by adopting two methods. One is a non-interferometricmethod, and the other is an intrerferometric method. After capturing the virtual SLM plane by adopting those two
methods, we try to find degrading factors and to improve the reconstructed hologram image by compensating forthem.
In Fig. 1(a), the experimental setup is shown, where both the interferometric method and the non-interferometricmethod are established to estimate the virtual SLM plane. In our experiment, a digital micro-mirror device(DMD),
which has the minimum pixel pitch of 13.68 μm and the resolution of 1024 Х 768, is used as an SLM. Two lenses
with the focal length of 180 mm and one spatial filter inserted between them constitute 4-f optics configuration, so
the unwanted signals can be filtered out. The captured image of the virtual DMD plane is shown in Fig. 1(b). After
analyzing the captured image of the virtual DMD plane, we tried to improve the image quality of thereconstructed hologram. Fig. 1(c) shows the reconstructed hologram image before improvement, and Fig. 1(d) is
the one after improvement.

Laser

CCD 2
Collimator 1
Spatial Filter

B/S 1

DMD 1

CCD 1

LENS 2LENS 1(b)

B/S 2

Mirror 2
Mirror 1

(c)

(a)

(d)

Fig. 1. (a) Experimental setup (b) Captured image of a virtual DMD plane (c) Reconstructed hologram(before compensation) (d) Reconstructed hologram (after compensation)
Acknowledgment
This work was supported by ‘The Cross-Ministry Giga KOREA Project’ grant from the Ministry of Science, ICT
and Future Planning, Korea.
References
1. R. Häussler, S. Reichelt, N. Leister, E. Zschau, R. Missbach, A. Schwerdtner, Proc. SPIE 7237, Stereoscopic
Displays and Applications XX, 72370S (2009)
2. Y. Lim, K. Hong, H. Kim, H. Kim, E. Chang, S. Lee, T. Kim, J. Nam, H. Choo, J. Kim, and J. Hahn, Opt.
Express, 24(22), 24999-25009 (2016).

DHIP 201746

p20-32

S. -H. Mun

3D Smart Table Display
Sang-Hyeok Mun, Muhan Choi*
School of Electronics Engineering, Kyungpook National University, Daegu 41566, South Korea*Tel.:82-53-950-5520, E-mail: mhchoi@ee.knu.ac.kr
OCIS codes: (110.6880) Three-dimensional image acquisition

We devised and produced a 3D Smart Table that could transform the appearance according to needs and requestsof the users. The size of the outer frame made of wood is 700×700×410 in millimeters, and the size of eachblock inside is 40×40×80 in millimeters. The array structure of the block has a square shape as a whole. In arow, 15 blocks are arranged and 15 blocks are arranged in a column. The driving part of the servo motor moves
180 degrees from the bottom to the top. The wire connecting the servo motor to each block turns the circularmotion of the servo motor into a linear movement of the block, allowing each block to move up and down to 4
centimeters.

Fig. 1. 3D Smart Table with Block Structure( Control system of structure and 3D Smart Table showing the letters ‘KNU’ )Control of the 3D Smart Table is realized by interlocking the structure with the Arduino board and LabVIEW
programming. The 225 servo motors are divided into 9 parts and connected to 9 servo motor controllers (Arduino
boards). These 9 servo motor controllers are driven by LabVIEW programming, and each servo motor-block partis individually controlled.
We designed a 3D Smart Table that can be changed in appearance to suit individual characteristeics and can beused semi-permanently. When IoT (Internet of things) technology is associated with furniture, it would beinteresting to apply 3D Smart Table to it. We think it is meaningful that we have implemented a 3D display of
analog ideas.
References
1. G. W. Johnson, LABVIEW GRAPHICAL PROGRAMMING, McGraw-Hill, Now York, (1997).
2. S. B. Hong, RHINO 3D 4.0, TaeHakWon, (2008)
3. Monk, Simon, Programming Arduino, McGraw-Hill, (2016)

DHIP 201747

p20-33

Y. -H. Lee

Tunable Graphene Metasurface Applicataion
Yong-Hoon Lee, Sang-Hyeok Mun, Inbo Kim and Muhan Choi*
School of Electronics Engineering, Kyungpook National University, Daegu 41566, South Korea*Tel.:82-53-950-5520, E-mail: mhchoi@ee.knu.ac.kr
OCIS codes: (090.1760) Computer holography

The focal length of a lens is determined by its geometric structure. Recently to overcome this limitation, metalens technology for controlling path of light wave through the spatial properties and the surface properties at theinterface of medium has been actively studied. However, it is impossible to actively control the transmission
characteristics including the focal length because the unit atoms constituting the conventional meta-lens consist ofnanoscale structures made of metal or dielectric

Fig. 1. Terahertz Graphene Meta-lens
In this study, we try to actively control the electrical properties of the meta-surface in block units by replacing
the metal and dielectric unit atoms with metal and graphene. To do this, it is necessary to establish high-precisiontransferring technology of graphene. And it is also required to adjust the phase shift to 2
through optimal
meta-atom design which enables effective gate control and maximizes changes in optical characteristics. Throughthe ion-gel patterning we control the gate voltage of the each graphene meta-atom block individually. The large
scale transferring of graphene is performed by polydimethylsiloxane (PDMS) stamp technique and it is used toenable precise transfer on the substrate of the meta-lens. Based on polarization-independent meta-atom design, we
also implement a meta-lens that operates regardless of the polarization of the incident wave. The variable focus
meta-lens we are aiming for is very thin and can be driven at super high speed. So it is expected that this active
meta-lens with graphene patterning will be applied to various devices in terahertz and mid-infrared range.
References
1. Muhan Choi, Seung Hoon Lee, et al., Nature, 470, 369 (2011)
2. Seung Hoon Lee, Muhan Choi, et al., Nature Materials, 11, 936 (2012)
3. Keun Soo Kim, Yue Zhao, et al., Nature, 457, 706 (2009)
4. Lei Zhang, Ghengtao Mei, Cheng-Wei Qiu, Adv. Optical Mater., 4, 818 (2016)

DHIP 201748

p20-34

J. YimCompressive holographic optical sectioning
Junkyu Yim, Seungwhi Yoo, and Sung-Wook Min
Dept. of Information Display, Kyung Hee University, 26 Kyunghee-daero, Dongdaemun-gu, Seoul 130-701,
Korea
E-mail: mins@khu.ac.kr
OCIS codes: (110.6880) Three-dimensional image acquisition; (100.6890) Three-dimensional image processing;(090.1760) Computer holography
Compressive holography enables us to reconstruct the voxels of three-dimensional volume with the highprobability provided those are sparse at the certain domains and the system matrix satisfies the restricted isometry
property(RIP) condition [1]. With the restricted number of measurements equal to the sensor pixel numbers, it ispossible for getting better 3D reconstruction compared to Fresnel back propagation, where the sectional 2D planes
are reconstructed by the multiplication with the interference pattern signal and the conjugation of quadratic phaseterms. Specifically, the bounds for the reconstruction of Fresnel holography are investigated as follows [2]:S  0.5(1  1/  )(1)where the S is the number of the non-zero elements of 3D object signal(voxels) and  is the coherence term.
The coherence term is the significant index which means the maximum correlation between the point spreadfunctions of 2D sectional planes if the reconstruction process is conducted at the spatial domain. As shown in theequation (1), the lower coherence, the better reconstruction in the compressive holography. In terms of the opticalsectioning, we can get the higher axial resolution with the lower coherence. If only two section planes are
considered, the sensing mechanism of Fresnel holography can be expressed as the vector-matrix multiplication
form:
f 
 f2 

g  f   1  2   1 (2)where the g is the interference pattern,  the sensing matrix, and f the section plane. In this case, thecoherence is the maximum corrleation between two sensing matrices 1 and  2 .

Fig. 1. System matrices for two section planes
Figure 1 shows the system matrices of Fresnel holography for two different section planes. Each matrix is themultiplication of the toeplitz matrices such as some propagation matrices and lens phase matrix. In this case,coherence is the similiarity between two matrices. We can adjust the numerical aperture of the optics system orincrease the distance between two section planes to get the low coherence. Therefore, the axial resolution of thesystem can be further with the same measurements(sensor pixel numbers).
Acknowledgment
This work was supported by 'The Cross-Ministry Giga KOREA Project' grant funded by the Korea
government(MSIT) GK17C0200, Development of Full-3D Mobile Display Terminal and its Contents)
References
1. David J. Brady, Kerkil Choi, Daniel L.Marks, Ryoichi Horisaki and Sehoon Lim, “Compressive
Holography”,Opt.Express,17, pp.13040-13049 (2009).
2. Tianlong Man, Yuhong Wan, Fan Wu, and Dayong Wang, “Self-interference compressive digitalholography with improved axial resolution and signal-to-noise ratio”, Appl.Opt. 56, pp.F91-F96, (2017).

DHIP 201749p20-35

J. KimDigital Holographic Tabletop display with vertical parallax by pupil tracking
Jaehan Kim, Hyongon Choo, Minsik Park and Jinwoong Kim
Digital Holography Research Section, ETRI, 218 Gajeong-ro, Daejeon, Korea
Tel.:82-42-860-1061, E-mail: kimjhan@etri.re.kr
OCIS codes: (090.2870) Holographic display; (090.5694) Real-time holography

We have implemented a holographic display capable of viewing 360 degrees in a horizontal direction byhorizontally concatenating many holograms with a narrow viewing angle using a spatio-temporal multiplexing
method[1][2]. In addition, vertical parallax was provided by using the pupil tracking method to find the 3D
position of the eye and streaming technique of the hologram data at the corresponding position.
In this paper, we describe the structure and method of providing vertical parallax in holographic display as
shown in Fig.1. According to the proposed method, a holographic display with vertical parallax using pupil
tracking information is implemented as shown in Fig.2. In order to verify the proper operation, we reconstructeddifferent holograms according to the six-step elevation angle of the pupil position, and finally confirmed therequired functions for the vertical parallax.

Fig. 1. Functional block diagram for providing vertical parallax on the holographic display

Fig. 2. Digital holographic table-top display system with vertical parallax.
Acknowledgment
This work was supported by ‘Giga KOREA Project’ granted from the Ministry of Science and ICT, KOREA.
(GK-17D0100 : Development of Telecommunications Terminal with Digital Holographic Tabletop Display)
References
1. J. Kim, K. Hong, Y. Lim, J-H Kim, and H-G Choo, IDW’16, 3D1-1 (2016).
2. J-H. Kim, K. Seol, E. Chang, K. Hong, H. Kim, M-S. Park, and J. Kim, IMID2017, P2-228 (2017).

DHIP 201750

p20-36

K. Kim

Optical design of table-top light field display
Kwangsoo Kim, Daerak Heo, and Joonku Hahn
School of Electronics Engineering, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu 41566,
South Korea
Tel.:82-53-950-5514, E-mail: jhahn@knu.ac.kr
OCIS codes: (100.6890) Three-dimensional image processing; (220.0220) Optical design and fabrication.
Table-top three-dimensional (3D) displays have a potential to change a flat table-top into 3D space. These
displays require large field of view in comparison of 3D display on the wall since the observer watches the display
at the end of the table. Various technologies have been applied to table-top style displays. S. Yoshida implemented
his display with plural small projectors to form multiple views[1] and Y. Lim et. al suggested a tabel-top
holographic display with a high speed spatial light modulator[2]. Light field method with microlens array has abenefit to make the system thin due to its scalability[3] and it may be possible to replace the top plate of the tablewith 3D display.

Fig. 1. Concept of table-top light field display.
Figure 1 shows a concept of Table-top light field display. This system is currently under construction and it
consists of plural small projectors in order to realize high resolution image on the screen and then light field isformed by micro-lens array. In this system, we designed the optical components including additional projectionlens attached to a conventional projector and micro-lens array for defining directions of views.
Acknowledgment
This work was supported by Civil-Military Technology Cooperation under Project Number 16-CM-DP-06.
References
1. S. Yoshida, “fVisiOn: interactive glasses-free tabletop 3D images floated by conical screen and modular
projector arrays,” SIGGRAPH Asia 2015 Emerging Technologies (SA '15), p. 12.
2. Y. Lim, K. Hong, H. Kim, H. Kim, E. Chang, S. Lee, T. Kim, J. Nam, H. Choo, J. Kim, and J. Hahn, “360degree tabletop electronic holographic display,” Opt. Express 24, 24999-25009 (2016).
3. Thomas L. Burnett, “Light-field Display Architecture and the Challenge of Synthetic Light-field Radiance
Image Rendering,” SID Symposium Digest of Technical Papers 48, 899–902 (2017).

DHIP 201751

p20-37

H. Do

Augmented Reality Near-eye Light-field 3D Display Using Retroreflector
Hyeongkyu Do, Young Min Kim, Hyunsik Sung, Ki-Hong Choi, Sungwon Choi and Sung-Wook Min
Dept. of Information Display, KyungHee University, Seoul, Korea
E-mail: mins@khu.ac.kr
OCIS codes: (120.2040) Displays; (120.2820) Heads-up displays; (120.4570) Optical design of instruments;(330.7338) Visually coupled optical systems; (110.6880) Three-dimensional image acquisition.

We propose an augmented reality near-eye light-field three-dimensional display system which leads theaccommodation cue. This system has simple optical components such as pinhole array, aperture, lens, and etc.,
which are compared with the complex optical components like the freeform lens or the holographic opticalelements.
By the retroreflector and the beam splitter, the conjugated images of the display, and aperture are formed insideof the human eye. Because the eye pupil restricts the light-field, the 2 mm aperture which is smaller than theminimum human eye pupil diameter can ignore the eye pupil size change. The pinhole array that has 1.104 mm
pitch and 0.184 mm size of the hole is used for imaging component in specific depth plane by integral imaging.
The image source is 5.46” full-color liquid crystal display (LCD) panel with 3840*2160 pixels. The lens used forthe improvement of the image sharpness has 75.4 mm focal length which is the distance from the display to theaperture. The distance from display to pinhole array is 42 mm.

Fig. 1. Experimental setup (left) and result (right)
The experimental setup and results are shown in fig. 1. The stripe object in fig. 1 is left to right reversal image
caused by the beam splitter, so left stripe is 0.3 m near object and right stripe is 1.5 m far object. The alphabet in
middle of the result is the integrated image that has accommodation in 0.3 m. When the camera focuses on nearstripe object, in fig. 1-(a), the alphabet image is focused. But the camera focus is on 1.5 m far object, the alphabet
image is defocused with near object, shown in fig. 1-(b).
Acknowledgment
This work was supported by the National Research Foundation of Korea(NRF) grant funded by the Korea
government(MSIT) (No.2011-0030079)
References
1. H. Hua and B. Javidi, Opt. Express 22, 13484-13491 (2014).
2. A. Maimone, D. Lanman, K. Rathinavel, K. Keller, D. Luebke, and H. Fuchs, in ACM SIGGRAPH Emerging
Technologies, 20 (2014)
3. A. Maimone, A. Georgiou, and J. S. Kollin, ACM Trans. Graph, 36, 4, Article 85 (2017)

DHIP 201752

p20-38

Y. Saita

Improvement in Phase Pattern Design for Holographic Shack-Hartmann
Wavefront Sensor with High Sensitivity
Yusuke Saita and Takanori Nomura
Faculty of Systems Engineering, Wakayama University, 930 Sakaedani, Wakayama, 640-8510, Japan
Tel.:+81-73-457-8184, E-mail: saita@sys.wakayama-u.ac.jp
OCIS codes: (090.2890) Holographic optical elements; (120.3940) Metrology; (120.5050) Phase measurement

A Shack-Hartmann wavefront sensor (SHWFS) which is composed of a microlens array and an image sensor is awell-known way to measure wavefront aberrations in an adaptive optics system widely used in astronomical andbio-medical fields1,2. An SHWFS has two important parameters to evaluate its capability. One is the dynamic
range which indicates the maximum measurable wavefront gradient and depends on the focal length of a
microlens array, the other is the sensitivity. The latter indicates the minimum detectable wavefront gradient andalso depends on the focal length of a microlens array. Although the longer focal length leads to higher sensitivity,
the dynamic range becomes smaller conversely. It is not easy that these parameters are compatible due to thistrade-off relationship. We have proposed the dynamic range expansion method without dependence on the focal
length, which is called the holographic Shack-Hartmann wavefront sensor (H-SHWFS)3. In this study, we try to
improve the sensitivity without decreasing the dynamic range by using the H-SHWFS.
The H-SHWFS has an arrangement of individually-designed computer-generated phase holograms(microhologram array) instead of a conventional microlens array. The discriminable patterns are obtained asreconstructed images from a microhologram array in an image sensor plane, and the expansion of the dynamic
range is achieved owing to the patterns. It is possible to improve the sensitivity without decreasing the dynamic
range by the H-SHWFS with longer focal length. However, the size of patterns becomes larger, and adjacentpatterns are subject to be overlap in the condition. To solve the problem, the design method of a microhologram
array is modified from the Fourier transform type to the lightwave propagation one based on the angular spectrum.
Figure 1 shows the reconstructed patterns from a microhologram array designed by the modified design method.
Although the size of dots constructing a pattern is larger as the focal length is longer, the whole size of patterns isalmost invariant.

Fig. 1. Reconstructed patterns from modified microhologram arrayswith the focal length of (a) 7mm, (b) 14mm, and (c) 21mm.
The numerical simulation was demonstrated to confirm the high sensitivity by the H-SHWFS with longer focal
length. As a result, the focal length of 14mm was better than one of 7mm. However, the low quality of the patternwith 21mm degraded the sensitivity through the reduction of the measurement accuracy. In the longer focal length,
shapes of the patterns must be robust for the low image quality.
References
1. H. Takami, et al., Publ. Astron. Soc. Japan 56, 225 (2004).
2. D. X. Hammer, et al., Opt. Express 14, 3354 (2006).
3. Y. Saita, et al., Optica 2, 411 (2015).

DHIP 201753

p20-39

S. Igarashi

GPU acceleration of hologram calculation
using an orthographic ray-sampling plane
Shunsuke Igarashi1, Tomoya Nakamura1,2, Kyoji Matsushima3, and Masahiro Yamaguchi1
School of Engineering, Tokyo Institute of Technology, Yokohama, Kanagawa, 226-8503, Japan
Tel.:+81-45-924-5296, E-mail: igarashi.s.ab@m.titech.ac.jp
2
PRESTO, Japan Science and Technology Agency, Chiyoda, Tokyo 102-0075, Japan
3
Faculty of Engineering Science, Kansai University, Suita, Osaka, 564-8680, Japan

1

OCIS codes: (090.1760) Computer holography; (090.2870) Holographic display; (090.1995) Digital holography

Abstract
Calculation of large-scale (over 10 gigapixels) holographic displays in high-resolution and realistic
appearance is a difficult problem in terms of computational cost. We previously proposed analgorithm using an orthographic ray-sampling plane to calculate such holograms. In this paper, thecalculation is accelerated by efficiently utilizing a GPU. The proposed method enables us efficient
calculation on GPUs by the division of the input light-ray data of 3D objects. In the experiment, a
128K x 128K hologram was computed and the acceleration effect of the proposed method wasverified comparing computational time with the calculation only using a CPU. The generated fringe
pattern was fabricated as an amplitude mask. We confirmed a realistic and detailed 3D image isreconstructed through the generated hologram.
1. Introduction
Holographic 3D display satisfies all depth cues by reconstructing the wavefront from objects. In principle, it ispossible to display 3D objects in their actual size and distance even if the objects are large and at far away from thehologram. However, synthesis of such computer generated holograms (CGHs) is not realized because of thecomputational load. Especially in case of large-scale, realistic and detailed objects, a new method must be invented.
The difficulty of calculating the large-scale and realistic holographic display comes from the required sampling
number of the wavefront and the computational complexity of the simulation of its propagation. If we adequately
sample a 100mm × 100mm wavefront in ±30 degrees, it should be sampled in 0.5μm pitch when the color isgreen. This means the wavefront data is sampled as 40 × 109 points. Simulation of wave propagation in this scaletakes infeasible time. We previously proposed a calculation method to generate such holograms using an
orthographic ray-sampling (ORS) plane [1], however, it still takes 13 hours to compute 128K × 128K holograms.
In this paper, we utilized a GPU to accelerate the calculation of the ORS plane method. We confirmed the proposed
method takes 1 hour to compute the 128K × 128K hologram, which is 13 times faster than our previous method.
The generated fringe pattern was fabricated as a binary amplitude mask. We also confirmed that a realistic anddetailed 3D image is reconstructed through the hologram.
2. ORS plane method and its acceleration using GPUs
Schematic of the proposed method is shown in Fig. 1. In the CGH calculation using ORS plane, a plane is definednear the objects, and parallel light-rays emitted from the target object are sampled. The sampled light-rays
correspond to orthographic images. In other words, an orthographic image is a set of spatially distributed parallel
light-rays. In this method, orthographic images are captured from various angles in order to obtain the light-field
passing through the ORS plane. Each captured orthographic image physically corresponds to discontinuously
sampled wavefront propagating toward a certain angle, thus the Fourier transform of an orthographic image is asmall region of Fourier transformed whole wavefront at the ORS plane, which also means the angular spectrum ofobjects. After the ray sampling, fast Fourier transform (FFT), the spectrum is multiplied with the transfer function
for wave propagation. The transfer function derived from Fresnel propagation, shifted angular spectrum method, or
any other wave-propagation model can be adapted. Finally, the wavefront at the hologram is obtained by inverse
FFT after the multiplication of the transfer fuinction. In this paper, the hologram plane is divided into small number

DHIP 201754

p20-39

S. Igarashi
of pixel to efficiently utilize a GPU.

Fig. 1. Schematic of CGH calculation using an orthographic ray-sampling plane.
3. Experimental results
In the experiment, we calculated a 128K × 128K hologram. In the calculation using only a CPU, the hologramis divided into 8 × 8 blocks. The calculation time of fringe pattern except the rendering time was around 13 hours.
Note that we used an Intel Core i7 4790K CPU (4.0 GHz) and a 32GB RAM and around 6 hours for rendering timein both methods. In the calculation using a GPU additionally, the hologram was divided into 64 × 64 blocks thathave 2048 × 2048 pixels. Each hologram tile was computed by a GPU (GeForce GTX 980), and the calculation
time was around 1 hour, which was 13 times faster than the CPU case.
The generated CGH was fabricated as an amplitude mask by the laser-lithography technique of Kan-Dai Digital
Holo Studio [2]. The pixel pitch of the mask is 0.8μm, which achieves ±23.3 degrees of viewing angle for a red
light. A 3D image reconstructed from the hologram illuminated by the laser light was shown in Fig. 2. A realisticand detailed 100mm × 60mm × 50mm 3D image is reconstructed through the generated hologram. The 3D
object is 80mm away from the hologram plane and the resolution of the 3D object is still high even in the distance.

Fig. 2. Optical reconstruction of a 3D image from the hologram generated by the proposed method.
4. Conclusion
We proposed an efficient method of calculating large-scale CGHs that reconstruct realistic and detailed 3D objects
using GPUs. The efficiency of the proposed method is confirmed by comparing the computational time with theprevious method. The feasibility of reconstructing high-quality 3D images is also demonstrated by the experiment.
A part of this work was supported by the MEXT strategic research foundation at private universities (2013-2017)
and Kan-Dai Digital Holo-Studio in Kansai University.
References
1. S. Igarashi, T. Nakamura, and M. Yamaguchi, “Fast method of calculating a realistic hologram based onorthographic ray-wavefront conversion,” Opt. Lett. 41, 1396–1399 (2016).
2. Kansai University, “Kan-Dai Digital Holo Studio,” http://holography.ordist.kansai-u.ac.jp/digitalholostudio

DHIP 201755

p20-40

M. Askari

Angular spectrum convolution based occlusion processing in computer
generated hologramMehdi Askari and Jae-Hyeung Park*
Dept. of Information and communication Engineering, Inha University, 100 Inha-ro, Nam-gu,
Incheon, 22212, South Korea
Email: *jh.park@inha.ac.kr
OSIC codes: (090.1760) Computer holography

In this paper, we propose an occlusion processing technique based on the fully-analytic triangular meshbased computer generated holography (CGH) to tackle the problem called non-occluding effect as shownin Fig. 1. The proposed method performs the occlusion processing not in the spatial domain likeconventional methods but in the angular spectrum domain.
The proposed algorithm for occlusion handling using convolution technique [1] is explained by,

AS1:2 f x,y   AS1 f x,y  AS1, 2 f x,y   AS 2 f x,y ,

The global angular spectrum of the rear mesh AS1(fx,y) is convoluted with the global angular spectrumof the current mesh AS2(fx,y) to determine the angular spectrum part AS1,2(fx,y) that should be occluded by
the current mesh as shown in Fig. 1. The convolution operation is performed in the hologram plane, not in
the individual local mesh plane. Therefore, the numerical propagations between the silhouette mask planes
are not required, which reduces the computational cost of the proposed method. The global angular
spectrum convolution achieves the blocking of the rear wave field in the tilted local mesh plane, not in theplane parallel to the hologram as in Fig. 1(e). Therefore, the proposed method is exact, being free fromoblique angle artifacts of the previous silhouette methods [2].

Fig. 1. (a)-(e) shows angular spectrum and reconstruction in current mesh plane,(f) shows reconstruction without occlusion processing.
References
1. H.-J. Yeom and J.-H. Park, “Calculation of reflectance distribution using angular spectrum convolution
in mesh-based computer-generated hologram,” Opt. Express 24(17), 19801-19813 (2016).
2. K. Matsushima, M. Nakamura, and S. Nakahara, “Silhouette method for hidden surface removal incomputer holography and its acceleration using the switch-back technique,” Opt. Express 22(20),24450-24465 (2014).

DHIP 201756

p20-41

S. -B. Ko

Speckle reduction using angular spectrum interleaving for triangular meshbased computer generated hologram
Seok-Beom Ko and Jae-Hyeung Park*
Dept. of Information and communication Engineering, Inha University, 100 Inha-ro, Nam-gu, Incheon, 22212,
Korea
E-mail: *jh.park@inha.ac.kr
OCIS codes: (090.1760) Computer holography

In this paper, we propose a method that eliminates speckle artifacts in the reconstruction of triangular meshbased computer generated hologram. The proposed method generates a number of holograms with different sets of
the interleaved plane carrier waves. The generated holograms are displayed sequentially with time-multiplexing,
achieving speckle-free reconstruction without sacrificing the viewing angle or depth of focus. We show the resultsof the proposed method in comparison with the conventional temporal averaging mehod [1] as shown Fig. 1

Figure 1. Experimental result(a) conventional temporal averaging method (b) proposed method
For the quantitative speckle measurement, we used a planar scene with uniform amplitude as the target object.
Figure 2 shows the measured speckle contrast. As can be seen in Fig. 2, the proposed method shows lower speckle
contrast in all time-multiplexing cases and it reaches the minimum speckle contrast level at N=5, which means thenumber of time-multiplexing required in the proposed method can be as small as 5.

Figure 2. Measured speckle contrast
References
1. W.F. Hsu and C.F.Yet, “Speckle suppression in holographic projection displays using temporal integration of
speckle images from diffractive optical elements,” Appl. Opt. 50(34), H50-H55 (2011).

DHIP 201757

p20-42

S. -B. Kim

See-through Maxwellian display
using waveguide and multiplexing holographic optical element
Seong-Bok Kim, Jae-Hyeung Park*
Department of Information and Communication Engineering, Inha University, Korea
Tel.: +82-32-860-7432, E-mail: * jh.park@inha.ac.kr
OCIS codes: (110.6880) Three-dimensional image acquisition; (100.6890) Three-dimensional image processing;(090.1760) Computer holography

Commercially available augmented reality (AR) / virtual reality (VR) devices in the form of head-mounted
displays (HMDs) present two-dimensional (2D) images using flat panel displays and lenses, and offer sense of
depth by giving binocular parallax. However, these devices generate vergence accommodation conflict (VAC) andusers can feel eye fatigue. To solve this problem, there are solutions generating 3D images like light field andholographic displays or removing the focal cue(accommodation) like Maxwellian displays. At this time,
Maxwellian displays are more suitable for HMD than 3D displays because the displays have low computationalload and less degradation in resolution. In Maxwellian displays, the collimated beam modulated by a display
panel is focused at the center of the eye pupil by using a lens to write images onto the retina directly. Therefore
users can always see clear images regardless of changing focal length of the user’s eye. Currently available
commercial Maxwellian displays consist of a scanning mirror and a concave mirror. So users can not see seethrough views where the mirror is located. The device is complicated and bulky because mechanical equipment
such as a scanning mirror are used. Also, the principle of Maxwellian display accompanies disadvantages that theeyebox size is limited to the pupil size. To solve these disadvantages, we propose a transmissive Maxwellian
display using a multiplexed HOE and waveguide with a beveled surface

Fig. 1. (a) proposed system configuration, (b) HOE recording setup
Figure 1(a) shows the structure of the proposed system. The system is composed of a waveguide with a obliqueside and a HOE that acts as multiple concave mirrors, 4-f system, aperture, transparent sparital light modulator(SLM). The parallel beam passes through the SLM and its high order diffraction terms are removed using the 4-f
system and aperture. The collimated beam is incident perpendicular to the oblique surface of the waveguide anddelivered to the HOE by total internal reflections. The HOE focuses the incident beam onto three spots as shownin Fig. 1(b), giving extended eyebox to the user. The proposed system is optically-see-through and compact.
Moreover, the proposed system increases the eyebox which has been one of the practical problems of theMaxwellian displays.
References
1. H.-J. Yeom, H.-J. Kim, S.-B. Kim, H. Zhang, B. Li, Y.-M. Ji, S.-H. Kim, and J.-H. Park, "3D holographic head
mounted display using holographic optical elements with astigmatism aberration compensation," Opt. Express
23(25), 32025-32034 (2015).

DHIP 201758p20-43

Y. -G. Ju

Acceleration of fully analytic mesh based computer generated hologram using
foveated rendering techniqueYeon-Gyeong Ju and Jae-Hyeung Park*
Dept. of Information and communication Engineering, Inha University, 100 Inha-ro, Nam-gu, Incheon,
22212, South Korea
Email: *jh.park@inha.ac.kr
OCIS codes: (090.1760) Computer holography; (090.2870) Holographic display; (100.6890) Three-dimensional
image processing

In this paper, we propose the method to accelerate the calculation of mesh based computer generated
hologram(CGH) using foveated rendering technique. Mesh based CGH is one of the CGH techniques which use
polygon mesh based computer graphical information. Foveated rendering is a technique used in head-mounted
displays (HMDs) to reduce the computational load by reducing the image resolution in peripheral area. Humaneyes can detect high details not within entire field of view, but within only tiny area around the center of our fieldof view. Using this characteristic of human eyes, we can reduce the image quality outside of the eye fixation area,
while maintaining the perceived image quality. We applied this foveated rendering to mesh based CGH to reducethe computation time without perceived quality degradation.
Figure 1 shows the simulation result of the proposed method. Figure 1(a) and 1(d) are the hologram and its
reconstruction of the full resolution case, i.e. when the proposed method is not applied. Figure 1(b), 1(c), 1(e), and1(f) are the foveated rendered case, when we supposed the yellow circular area is the eye fixation area. Table 1
shows the computation time reduction when we implement the proposed method. The result is the case of Fig.
1(b), and 1(e). The computation time of the mesh based CGH is proportional to the number of meshes, and it canbe found that the computation time is reduced by about 46%.
We have presented the method to accelerate the calculation of mesh based CGH, in the case of HMD. We expect
the proposed technique would find its applications in the contents generation for holographic 3D HMDs.

(a)
(b)
(c)
(d)
(e)
(f)
Fig. 1. Comparison the hologram and their reconstruction between the full resolution and the foveated
rendered case. (a): Hologram of the full resolution case. (b),(c): Hologram of the foveated renderedcase. (d)-(f): Reconstruction of (a)-(c).
Full Resolution Case

Foveated Rendered Case

# of meshes outside the2722
544
focusing area
# of meshes in the whole area
4212
2034
Computation time
66.25s30.72sTab. 1. Comparison the computation time and the number of the meshes between fulll resolution andfoveated rendered case
References
1. M. Askari, S. B. Kim, K. S. Shin, S. B. Ko, S. H. Kim, D. Y. Park, Y. G. Ju, and J. H. Park, Occlusion handlingusing angular spectrum convolution in fully analytical mesh based computer generated hologram, Opt.
Express, vol. 25, no. 21, pp. 25867-25878 (2017).
2. J. S. Hong, Y. M. Kim, S. H. Hong, C. S. Shin, and H. J. Kang, Gaze contingent hologram synthesis forholographic head-mounted-display, SPIE, vol 9771, pp. 97710K 6 (2016).

DHIP 201759p20-44

K. S. ShinAn analysis of light field type head-up displays for vehicles
KwangSoo Shin, Jae-Hyeung Park*
Dept. of Information and communication Engineering, Inha University
Email: *jh.park@inha.ac.kr
OSIC codes: (110.6880) Three-dimensional image acquisition; (100.6890) Three-dimensional image
processing; (090.1760) Computer holography

Recently, head-up displays (HUDs) are attracting more attentions due to increase of interest in vehicle
infotainment system. There are, however, several problems in HUD system. Distance of the displayed
images to a driver is one of the major limitations. Current HUD systems usually present images at 2.5
meters from the driver. If the image distance becomes longer, the system volume of HUD unit also increases
to maintain similar magnification. So the maximum image distance is limited in current system. It is also a
problem that the image distance is not variable but fixed, which makes it difficult to match virtual image toreal objects. To solve these problems, recently application of 3D displays to HUD system has beenstudied.[1] In this paper, we analyze viewing parameters of the 3D displays and those of HUD.

Fig. 1. configuration of AR 3D HUD
According to the configuration shown in Fig. 1, FOV and Eyebox are estimated by

FOV ≈ min(w d

li
w
, l )
l o (li + l s + l e ) l s + l e

l +l +ll +lEyebox = w l i s e - w d s e
li
lo

(1)

where li is distance between lens and virtual image. wd, wl are size of display and mirrors respectively. With
3D imaging system, virtual image can be represented much farther than existing system as

1
1
1=
lo lv,near - ls - le f1
11=
ldepth + lo lv,far - ls - le f(2)

where f is focal length of lens. When 3D system provides virtual image in ldepth distance from panel, depthof virtual image changes as from lv,near to lv,far.
References
1. Y. Takaki, “Super multi-view windshield display for long-distance image information presentation,”Opt. Express 19(2), 704-716 (2011).

DHIP 201760

Key21a-1

M. Yamaguchi

Full-parallax light-field and holographic displays
Masahiro Yamaguchi
School of Engineering, Tokyo Institute of Technology, Yokohama, Japan
Tel.:81-45-924-5137, E-mail: yamaguchi.m.aa@m.titech.ac.jp
OCIS codes: (090.2870) Holographic display; (100.6890) Three-dimensional image processing; (090.1760)
Computer holography
A light-field display (LFD) reproduces the light-rays from a display screen so that virtual or real images are
generated, and an observer can perceive natural 3D image in the air without using 3D glasses or goggle. However,there are some limitations in LFD, such as the sampling of light-rays and the diffraction at the screen plane, and theresolution of image far from the screen plane becomes low. On the other hand, holography, which is wavefront
reconstruction technology, can also reconstruct light-field, while it is free from above limitations and highresolution image is obtained even in deep 3D scene. Thus, ray-based LFD is suitable for lower-resolution large
displays, esp the 3D image near the screen, whereas wavefront-based LFD is advantageous in higher-resolution
deep 3D scene [1]. We apply the concept of integrating ray-based and wavefront-based techniques to computational
holography [2-4] and interactive 3D touch display [5].
In the calculation of computer generated hologram (CGH), rendering is done by using off-the-shelf 3D CG
software, while the light propagation is calculated based on wavefront [Fig. 1]. Then, realistic images are generatedusing 3D CG software, and high-resolution 3D images are reconstructed in a deep 3D scene [Fig. 2].

Fig. 1 Hologram computation
using R2W conversion

Fig. 2 Reconstructed image fromthe CGH.

Fig. 3 The 3D touch sensing display
using holographic LFD.

For the interactive 3D user interface, a hologram is used as an optical element for generating light-field, andimage data are projected by a high-resolution projector [Fig. 3]. Then, we can generate interactive light-field display
with floating 3D image, which is a real image. If a user touches the image, the top of fingertip is irradiated by thereconstructed real image. The color of scattered light is detected by a color camera, and it is used for user interface.
The integration of light-field and holography will provide great advantage. The examples are demonstrated in thecomputation of high-quality hologram and the interactive 3D touch interface, assisted by light-field technology.
Acknowledgment
This work is performed in collaboration with Prof. Kyoji Matsushima, Kansai Univ. and our Lab members, Ryo
Higashida, Shunsuke Igarashi, and Dr. Tomoya Nakamura.
References
1. M. Yamaguchi, "Full-Parallax Holographic Light-Field 3-D Displays and Interactive 3-D Touch," Proc. of theIEEE, 105, 5, 947-959 (2017).
2. K. Wakunami and M. Yamaguchi, "Calculation for computer generated hologram using ray-sampling plane," Opt.
Express 19, 10, 9086-9101 (2011)
3. S. Igarashi, T. Nakamura, and M. Yamaguchi, "Fast method of calculating a photorealistic hologram based onorthographic ray–wavefront conversion," Opt. Lett. 41, 7, 1396-1399 (2016).
4. S. Igarashi, T. Nakamura, M. Yamaguchi, K. Matsushima, "Efficient calculation method for realistic deep 3D
scene hologram using orthographic projection," Proc. SPIE, 9771, 97710O, (2016).
5. M. Yamaguchi, R. Higashida, "3D touchable holographic light-field display," Appl. Opt. 55, 3, A178-A183, (2016).

DHIP 2017
61

Inv21a-1

M. Park

Table-top Holographic Display with Full Parallax
Minsik Park, Yongjun Lim , Keehoon Hong, Eun-Young Chang, Hayan Kim, Jaehan Kim and Jinwoong Kim
Electronics and Telecommunications Research Institute (ETRI), 218 Gajeong-ro, Daejeon, 34129, South Korea
Tel.:82-42-860-1231, E-mail: pms@etri.re.kr
OCIS codes: (090.2870) Holographic display; (090.1760) Computer holography

Digital holographic display has been actively researched for the development of an ultimate three-dimensional
display because it can obviously solve the vergence-accommodation conflict problem of an existing threedimensional display [1]. Digital holographic display, however, can’t have a sufficient spatial bandwidth due to thelimited performance of a commercialized spatial light modulator (SLM), which results in limitations on both asize and a viewing angle of the image reconstructed from hologram. In order to remove such restrictions, we have
not only studied a flat-panel holographic display using spatial multiplexing [2] but also developed a table-top
holographic display using temporal multiplexing [3] to expand a spatial bandwidth. A high-speed DMD is applied
as a SLM to realize the temporal-multiplexing in table-top holographic display. Figure 1 shows the system
structure of the implemented table-top holographic display. It consists of combination optics including three
DMDs corresponding to each RGB light source for reconstructing a colour hologram, 4F optics not only forremoving spatial noise (DC and twin image) but also for optically magnifying the reconstructed hologram image,and rotation optics including the hollow motor synchronized with the RGB DMDs to display colour hologram
images in a 360-degree direction.

Fig.1. Table-top Holographic Display
In addition, we have tried to develop a vertical parallax in 20-degree for the verfication purpose of the feasibilty
to support a full parallax in table-top holographic display by integrating both an eye-tracking function of camera
system and a projection function of DMD. We will elaborately discuss the optical design to realize the floating
hologram image, the principle to apply the temperal-multiplexing and the method to implement the full parallax inthe table-top holographic display.
Acknowledgment
This research was supported by GigaKOREA project, (GK17D0100, Development of Telecommunications
Terminal with Digital Holographic Table-top Display).
References
1. J. Hong et al., “Three-dimensional display technologies of recent interest: principles, status, and issues, ” Appl.
Opt. vol. 50, pp. H87-H115, 2011.
2. M.S. Park et al., “Digital holographic display system with large screen based on viewing window movement for3D video service,” ETRI Journal, vol. 36, no. 2, pp. 232-241, 2014.
3. Y. Lim et al., “360-degree tabletop electronic holographic display”, Opt. Express,24(22), 24999-25009, 2016.

DHIP 2017

62

Inv21a-2

Y. Sando

Enlargement of viewing zone of holographic 3D display
using a parabolic mirror
Yusuke Sando3, Kazuo Satoh3, Takahiro Kitagawa3, Makoto Kawamura3, Daisuke Barada1,2 and Toyohiko Yatagai1
1Center for Optical Research & Education, Utsunomiya University, 7-1-2 Yoto, Utsunomiya, Tochigi 321-8585,
Japan
2

Graduate School of Engineering, Utsunomiya University, 7-1-2 Yoto, Utsunomiya, Tochigi 321-8585, Japan
Osaka Research Institute of Industrial Science and Technology, 2-7-1 Ayumino, Izumi, Osaka 594-1157, Japan
Tel.:81-725-51-2713, E-mail: sando@tri-osaka.jp

2

OCIS codes: (090.1760) Computer holography

Recently, holographic 3D display has been actively researched. To put the holographic 3D display into practicaluse, the problem of the narrow viewing zone must be solved. However, the view zone of the hologram is limited
in principle due to the shape. For example, in the planar hologram, no one can never observe reconstructed images
from the opposite or lateral sides of the hologram. To overcome this shape-based limitation, we propose one
appraoch of the introduction of a convex parabolic mirror between the hologam and viewers to realize theextremely wide viewing zone. Differetly from other techniques, it should be noted that the vertical viewing zone
can be also enlarged in addition to the horizontal viewing zone. The enlargement effect is the same as that of ahemispherical-shaped hologram.
The schematic of a holographic 3D display using a convex parabolic mirror is illustrated in Fig. 1. The wavefront
modulated by a hologram is Fourier-transformed by a lens. The non-diffracting wave and the conjugate wave areremoved by a single sideband filter placed at the back focal plane of the lens. Then, the wavefront enters theconvex parabolic mirror, and reflects radially. If the Fourier-transform type hologram is properly designed
considering the parabolic mirror reflection, a 3D image can be reconstructed as a virtual images near the focal
point of the parabolic mirror. Because the diverging angle of this reflected wavefront is quite large, extremely
wide viewing zone is realized. The extended viewing zone of the horizontal (azimuthal) and vertical (zenithal)directions are 180° and 90°, respectively. Some optically reconstructed images observed from various directions
are shown in Fig. 2. The 3D object used for this experiment is a dice. θ and φ indicates vertical and horizontal
angles. As can be seen from Fig. 2, the proper perspective images are reconstructed in accordance withobservation directions, and extremely large viewing zone has been demonstrated.

Fig. 1. Schematic of holographic 3D display using a convex
parabolic mirror. OL: objective lens, SF: spatial filter, f:
focal length of the lens.

Fig. 2. Optically reconstructed images.

Acknowledgment
This research was partially supported by JSPS KAKENHI Grant Number JP15K21699.

DHIP 2017

63Inv21a-3

S. -K. Kim

Formation of dynamic viewing zone in autostereoscopic 3D display
Sung-Kyu Kim*, Ky-Hyuk Yoon, and Min-Koo Kang
Imaging Media Research Center, KIST, Seoul, Korea*e-mail: kkk@kist.re.

Abstract: Conventional autostereoscopic multiview 3D displays suffer from the crosstalk and freedom ofviewing condition. Two type of dynamic viewing zone methods are developed to reduce the crosstalk andobservation freedom; they are based on the viewing z
one fusion (VZF) and dynamic maximal viewing zone (DMVZ). These methods are verified in the developed
parallax type multiview and HDMV 3D displays.
1. Introduction
Glasses-based 3D displays should wear uncomfortable special glasses. For this reason, popularization of 3D displays isdelayed. For that reason, the development of an autostereoscopic 3D display is important. However, in the case of the noneyeglass system, 3D resolution is degraded and the degree of freedom of observation is known to be a problem. VZF
proposed a solution to the problem of crosstalk and limitation of observation freedom. (1~3) And DMVZ presents its findings
in a way that can improve the 3D resolution in the case of HDMV or SMV and at the same time relax the limit of observer
position. (4)2. Concepts of VZF and DMVZ
The concept of VZF is at Fig.1 and the basic idea of DMVZ is at Fig. 2.

Fig. 1 Concept of VZF

DHIP 2017

64

Inv21a-3

S. -K. Kim

Fig. 2 Concept of DMVZ

3.

Conclusions

In this presentation, we discuss on the low crosstalk technique using eye-tracking system and wide 3DOF viewing position
based on face tracking system. Additionally both methods support full parallax when real time rendering activates.

4. References
1. Sung-Kyu Kim, Ki-Hyuk Yoon, Seon Kyu Yoon, and Heongkyu Ju, “Defragmented image based autostereoscopic 3D
displays with dynamic eye tracking,” Optics Communications, 357, pp.185-192, (2015)
2. Korea Patent, “10-1073512, 3-dimensional displaying apparatus and driving method thereof,”(2011).
3. Korea Patent, “10-2012-0072384, Apparatus for 3-dimensional displaying using dynamic viewing zone enlargement for
multiple observers and method thereof” (2012).
4 Korea Patent, “2017-0103605, Autostereoscopic 3D display using DMVZ,” (2017).

DHIP 2017

65

Inv21a-4

H. Yamamoto

Aerial Multi-Modal Information Display
Hirotsugu Yamamoto1,2, Tomoyuki Okamoto1, Shusei Ito1,and Ryosuke Kujime1,2
1
Dept. of Optical Engineering, Utsunomiya Univ., Utsunomiya City, Tochigi 321-0904, Japan
Tel.:81-28-689-7074, E-mail: hirotsugu@yamamotolab.science
2
ACCEL, JST, Utsunomiya City, Tochigi , JapanOCIS codes: (120.2040) Displays; (110.6820) Thermal imaging; (110.7170) UltrasoundAerial display enables us to handle visual information directly in the mid-air. Because there is no hardware at theaerial screen position, it is important to give appropriate feedback for a viewer. This paper proposes sometechniques to give multi-modal sensation for the viewer of an aerial display. We have developed an aerial display
technique, called aerial imaging by retro-reflection (AIRR)1, which features a wide viewing angle, scalability, andmass-productivity. In order to converge sound and ultrasonic wave, we have fabricated a crossed-mirror array(CMA), which is made of transparent acrylic plates with hollow apertures. Furthermore, we have formed an aerial
heater by converging far-infrared radiations with double-layered arrays of rectangular mirror (WARM)2.
This paper reports our developments on aerial multi-modal display in combination of AIRR, CMA, and WARM.
We have developed a visual, thermal and acoustic floating aerial display3. The composition of our system isshown in Fig. 1 (a). Aerial images are formed in the air, as shown in Fig. 1 (b). We have placed a electric heater towarm up an aerial image of fire. By placing a thermo-chromic screen, as shown in Fig. 1 (c), we have confirmedthat only a part of the aerial images is heated. Because a parametric speaker and a CMA are installed in the left
side of the aerial screen, sound pressure is locally increased in the mid-air. Thus, our visual, thermal, and acoustic
aerial display gives multi-modal sensations for users.
Another application of multi-modality is to guide a viewer to the viewing position of a secure aerial display4. We
have introduced an ultrasonic transducer array to give haptic sensation for a viewer5. As shown in Fig. 1 (e), byadjusting the phases of the transducers, Haptic sensation is given at an arbitrary position. This haptics is used topresent the limited viewing position of the aerial secure display.

(a)

(b)

(d)

(c)

(e)

Fig. 1. (a) Composition of our developed aerial multi-modal information display. (b) Observation of formed
aerial images on a screen. (c) Observation of the formed aerial thermal image on a thermo-chromic screen.
(d) Conversing sound in the mid-air. (e) Haptic sensation by use of an ultrasonic transducer array.

1.
2.
3.
4.
5.

References
H. Yamamoto, et al., Opt. Exp., 22(22), 26919 (2014).
T. Okamoto, et al., Proc. IDW/AD‘16, 3D6/3DSA7-4 (2016).
H. Yamamoto, et al., SIGGRAPH Posters 2017, 16 (2017).
K. Uchida, et al., Opt. Rev., 24 (1), 72 (2017).
S. Ito, et al., Proc. IDW’17, HAPp1-4 (2017).

DHIP 201766

Inv21a-5

B. LeeMetasurfaces for holograms
Byoungho Lee * and Gun-Yeal Lee
School of Electrical and Computer Engineering and Inter-University Semiconductor Research Center,Seoul National University, Gwanak-Gu Gwanak-ro 1, Seoul 08826, Korea*Tel.:82-2-880-7245, E-mail: byoungho@snu.ac.kr
OCIS codes: (110.6880) Three-dimensional image acquisition; (100.6890) Three-dimensional image processing;(090.1760) Computer holography

Holography, which is an optical technology that reconstructs the wavefront of electromagnetic waves to provide
vivid three-dimensional images, has been of great interest due to its potential for the next generation imaging
technology. In general, conventional digital holography has been based on various optoelectronic devices such asa spatial light modulator and a digital micromirror device. However, these kinds of devices have been sufferingfrom several issues due to their large pixel size compared to operating wavelengths, leading to low resolution,
narrow viewing angle, and severe noises generated from undesirable diffraction orders and twin images. More
importantly, conventional holographic technologies are usually based on either amplitude- or phase-only
modulation scheme with incomplete approximations of object images. It is notable that a subwavelength scale ofthe pixel is required for realizing enough viewing angles and high spatial resolutions of holographic images.
Metasurfaces, which are planar optical elements with composition of artificially fabricated subwavelengthstructures, have been extensively studied recently. It was found that wide ranges of light-mater interactions can beobtained by designing the morphologies of subwavelength nanoantennas in metasurfaces [1]. Recently,
metasurfaces are expected to pave the path for high quality spatial light modulators that can overcome thelimitations of conventional optical components. Various metasurfaces have been investigated as holographic
devices with control of phase and polarization of light, and show great performances including wide viewing
angles, high resolutions, and no diffraction orders in holographic images.
In this presentation, several metasurface platforms for holographic generation and manipulation ofelectromagnetic waves will be presented. First, we will briefly explain the physical mechanisms and concepts of
the holographic metasurfaces. Various types of meta-atoms providing phase modulations will be introduced in thispresentation, and their applications will also be discussed [2, 3]. Moreover, we would like to introduce the next
step of those kinds of metasurfaces, which provides not only phase-modulations but also amplitude-modulations,leading to complex-amplitude modulations. In particular, C-shpaed nanostructures for generating ultra-compact
Airy beams will be first introduced where the C-shpaed metasurface provides both full phase-modulations andbinary amplitude-modulations [4]. Then, X-shaped silicon metasurfaces, which provide complete control of both
amplitude and phase of visible light, will be introduced, and their physical mechanisms will be explained [5].
Based on the X-shaped metasurfaces, full complex-amplitude modulated holograms with subwavelength spatial
resolutions will be suggested as a promissing application of this metasurface platform. Finally, conclusions withthe future direction of the metasurface holography study will be breifly discussed.
Acknowledgment
This research was supported by Basic Science Research Program through the National Research Foundation of
Korea (NRF) funded by the Ministry of Science, ICT & Future Planning (2017R1A2B2006676).
References
1. N. Meinzer et al., Nat. Photon. 8, 889–898 (2014).
2. G. Zheng et al., Nat. Nanotech. 10, 308–312 (2015).
3. A. Arbabi et al., Nat. Nanotech., 10, 937–943 (2015).
4. E.-Y. Song et al., Adv. Opt. Mater. 5(10), 161028 (2017).
5. G.-Y. Lee et al., arXiv:1706.09632 (2017).

DHIP 201767

Inv21p-1

O. Matoba

Common-path incoherent digital holography
Osamu Matoba1, Xiangyu Quan1 and Yasuhiro Awatsuji2
Graudate School of System Informatics, Kobe University, Rokkodai 1-1, Nada, Kobe 657-8501, Japan

1

Tel.:81-78-803-6235, E-mail: matoba@kobe-u.ac.jp
Graduate School of Science and Technology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto
606-8585, Japan

2

OCIS codes: Digital holography; (110.6880) Three-dimensional image acquisition; (180.2520) Fluorescencemicroscopy; (090.1970) Diffractive optics
Incoherent digital holography is one of the hot topics in digital holography because it can be applied tobiological tissue in fluorescence imaging. There are two configurations. One is Michelson-type interferometer. It
can realize an off-axis holography, but two separated arms are required and then it is difficult to make the systemcompact. The other configuration is a common-path geometry using diffractive optical elements. FINCH is one ofthe pioneer works of the incoherent digital holography. In this system, two focusing lenses implemented by aphase-mode spatial light modulator can generate two diffracted waves from the fluorescence light, and then two
waves are interfered in the image sensor. Phase shifting method is applied to improve the reconstructed quality.
However, it prevents from the single shot measurement. Recently, we have proposed an off-axis incoherent digitalholography in a common-path configuration [1]. This configuration is suitable for the multi-modal imaging where
the phase and the fluorescence 3D distributions can be measured simultaneously [2, 3].
Figure 1 shows our concept of the common-path off-axis incoherent digital holography. In this setup, the two
focusing lenses with diffraction gratings are used to implement an off-axis configuration. In this setup, themodulated signals travels in different directions from the optical axis and then the unmodulated waves including
the surface reflection of the optical elements and spatial light modulator can be eliminated. This setup is very
stable and makes the system compact. These properties are suitable for optical microscope. Figure 2 shows thepreliminary experiment by using a quasi-point light source using a LED. From Fig. 2(a), the off-axis hologram
can be seen and the original point light source is reconstructed well by changing the reconstruction distance. In thepresentation, we will discuss the possibility of the fluorescence measurement and the biological samples.

Fig. 1. Concept of common-path off-axis
incoherent digital holography.

(a)(b)
Fig. 2. Experimental results using a point-like source
by LED. (a) hologram and (b) reconstructed image.
Acknowledgment

A part of this work was supported by JSPS KAKENHI Grant Number 15H03580 and JSPS KAKENHI Grant
Number 16J05689.
References
1. X. Quan, O. Matoba, and Y. Awatsuji, Opt. Lett., 42(3), 383 (2017).
2. X. Quan, K. Nitta, O. Matoba, P. Xia, and Y. Awatsuji, Opt. Rev., 22, 349 (2015).
3. O. Matoba, X. Quan, P. Xia, Y. Awatsuji, and T. Nomura, Proc. of the IEEE, 105(5), 906 (2017).

DHIP 2017

68Inv21p-2

M. Choi

Photonic meta-devices based on optical path control
Muhan Choi* , Inbo Kim, Jinhang Cho, Sang-Hyeok Mun
School of Electronics Engineering, Kyungpook National University, Daegu 41566, South Korea*Tel.:82-53-950-5520, E-mail: mhchoi@ee.knu.ac.kr
OCIS codes: (160.3918) Metamaterials, (140.3945) Microcavities,

1. Gradient index micro-cavity designed by transformation optics
The optical mode properties of dielectric cavities, such as quality factor and emission directionality, canbe tailored at will by using transformation optics [1-3]. The dielectric microcavity with the spatiallyvarying refractive index profile can be implemented by drilling subwavelength-scale air holes in adielectric slab. The proposed design scheme of microcavities based on the transformation optics can beapplied to new kinds of laser beyond the conventional microcavity laser diodes.
2. Active graphene meta-lens operating in terahertz regime
The variable focus meta-lens has been designed by using actively controllable metasurface blocks. The
meta-surface blocks are composed of metallic unitcells and a graphene layer in which opticalconductivity can be controlled individually by the gate voltage through the ion-gel gate. The metalens isvery thin and can be operated with very high modulation speed. It is expected that the active meta-lens
will be applied to various devices in terahertz and mid-infrared range.[4-7]Fig. 1. Gradient index microcavity designed by transformation optic and Terahertz Graphene Meta-lensReferencesJ. B. Pendry, D. Schuring, and D. R. Smith, Science, 312, 1780, (2006)
Leonhardt, U., Science, 312, 1777 (2006)
Yushin Lee, et al, , Nature Photonics, 10, 647 (2016)
Hoon Lee, et al., Nature, 470, 369 (2011)
Seung Hoon Lee, Muhan Choi, et al., Nature Materials, 11, 936 (2012)
Keun Soo Kim, Yue Zhao, et al., Nature, 457, 706 (2009)
7. Lei Zhang, Ghengtao Mei, Cheng-Wei Qiu, Adv. Optical Mater., 4, 818 (2016)
1.
2.
3.
4.
5.
6.

DHIP 2017

69

Inv21p-3

T. TaharaMultidimensional imaging with phase-shifting interferometry
Tatsuki Tahara1,2, Reo Otani3, Yasuhiko Arai1 and Yasuhiro Takaki4
1
Faculty of Engineering Science, Kansai University, 3-3-35 Yamate-cho, Suita, Osaka, 564-8680, Japan
Tel.:81-6-6368-1757, E-mail: tahara@kansai-u.ac.jp
2
PRESTO, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan
3
SIGMAKOKI CO. LTD., 17-2, Shimotakahagi-shinden, Hidaka-shi, Saitama 350-1297, Japan
4
Institute of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei,
Tokyo 184-8588, JapanOCIS codes: (090.0090) Holography; (090.1995) Digital holography; (090.1705) Color holography.

Digital holography is a technique to obtain 3-D information without a mechanical scan by recording a digitalhologram and reconstructing a 3-D image using a computer [1]. The technique has the ability for sensing
multidimensional information such as 3-D space, phase, and multiple wavelengths simultaneously. Phase-shifting
interferometry is a powerful technique that can utilize a full space-bandwidth product of an image sensor with ahigh signal-to-noise ratio [2]. As a method to record multidimensional information with phase-shifting, we havepresented phase-shifting interferometry selectively extracting wavelength information since 2013 [3-6].
Figure 1 illustrates the principle of the presented multiwavelength digital holographic technique [3-6]. A
monochrome image sensor records wavelength-multiplexed phase-shifted holograms sequentially. As a result,
wavelength information is superimposed on space and spatial frequency domains and is separated in the polar
coordinate plane. Based on phase-shifting interferometry, an object wave at the desired wavelength is selectively
extracted and complex amplitude images at multiple wavelengths are reconstructed. It is worth noting that 2N + 1
wavelength-multiplexed holograms are sufficient in the initially proposed scheme [3,4,6] where N is the numberof wavelengths measured and the number can be decreased to 2N [5]. In the talk we describe numerical andexperimental results and also introduce single-shot incoherent digital holography with phase-shifting [7].

Fig. 1. Principle of phase-shifting interferometry selectively extracting wavelength information.
Acknowledgments
This study was partially supported by Japan Science and Technology Agency (JST), PRESTO, Grant number:JPMJPR16P8, Konica Minolta
Science and Technology Foundation, the Japan Society for the Promotion of Science (JSPS), MEXT-Supported Program for the Strategic
Research Foundation at Private Universities, and Research Foundation for Opt-Science and Technology.

References
1. Y. Takaki, H. Kawai, and H. Ohzu, Appl. Opt. 38, 4990 (1999).
2. J. H. Bruning, et al., Appl. Opt. 13, 2693 (1974).
3. T. Tahara, S. Kikunaga, Y. Arai, and Y. Takaki, in Proceedings of Optics and Photonics Japan 2013 (OPJ),
13aE9, Nara, Japan, Nov. 13, 2013. (in Japanese)
4. T. Tahara, R. Mori, S. Kikunaga, Y. Arai, and Y. Takaki, Opt. Lett. 40, 2810 (2015).
5. T. Tahara, R. Mori, Y. Arai, and Y. Takaki, J. Opt. (IOP Publishing) 17(12), 125707 (2015).
6. T. Tahara, R. Otani, K. Omae, T. Gotohda, Y. Arai, Y. Takaki, Opt. Express 25, 11157 (2017).
7. T. Tahara, T. Kanno, Y. Arai, and T. Ozawa, J. Opt. (IOP Publishing) 19, 065705 (2017).

DHIP 201770

Inv21p-4

K. -H. Lee

Quantitative verification for whether LF display system can serve
accommodative function to the observer
Kwang-Hoon Lee1,*and Seon Kyu Yoon1
1
Spatial Optical Information Research Center, Korea Photonics Technology Institute, Gwangju, Korea
Tel.:82-62-605-9324, *E-mail: geniuspb@kopti.re.kr
OCIS codes: (110.6880) Three-dimensional image acquisition; (100.6890) Three-dimensional image processing
The purpose of this approach is that verifying whether the LF display provides accommodative function, andquantifying the focusable range at the reconstruction image space in which permitted by the focusable powerserved by the display. Our point of view is quite different compared to the existing reports. They had only dealt
with the subjective accommodation inducing by observer, in this work, but we had focused to the objective
accommodation providing by the LF display in contrast.
The proposed objective accommodation assessment system is consisted by several core parts such as the opticalsystem mimiced the model of pseudo human eye, the spatial filter dividing direction of rays which are passed thetwo-holes of Hartmann mask located in front of the cornea lens, the optical circumstance given deep depth of fieldover f/4, and the designed special pattern optimized to the display in which verifying either the formed image on
the detection plane was focused or not. The LF display used in the investigation is designed that it serves 72
multi-views with 7mm of the inter distance between adjacent center positions of each viewing zone. The entrance
pupil size (as the cornea lens) of the optical system in the equipment was designed that it can be acceptable threeadjacent viewing zone widths. The positions of three virtual objects (Near, Middle – on the display and Far) arerepresented the couple of the rays having each direction toward to the optical system, and the objects were
pattered to the superposed multi-view image within the special window area. Also the window area satisfied thefocusable range providing by the display.

Fig. 1. Experimental results by the designed optical system verifying objective accommodation served by LF display

Consequently, we verified that LF display (based on horizontal parallax only model) can serve the objective
accommodation function to the observer at the special condition. In the experimental result, non-focused object
image was split on the detector as double image form which is not affected blur effect induced by optical system,
and its form was contrasted to the focused case. Additionally, the result showed that the amount of split in the
double image represents proportionally to the relative object distances in the object space.
Acknowledgment
This work was supported by 'The Cross-Ministry Giga KOREA Project' grant funded by the Korea government (MSIT) (No.GK17C0200, Development offull-3D mobile display terminal and its contents )References
1. David A.Atchison, G. Smith, Optics of the Human Eye, Butterworth-Heinemann press, (2000)

DHIP 201771

Inv21p-5

K. Harada

How to control polarization color
Kenji Harada, Toshiki Matsuzaki and Huangyi Qin
Department of Computer Science, Kitami Institute of Technology,
165 Koen-cho, Kitami, Hokkaido 090-8507, Japan
Tel.:81-157-26-9323, E-mail: harakan@cs.kitami-it.ac.jp
OCIS codes: (100.0100) Image Processing; (100.4998) Pattern recognition, optical security and encryption;(330.5000) Vision - patterns and recognition

A birefringent cellophane tape or a polymer sheet exhibits polarization color (interference color) by polarizer. We
propose a novel technique for viewing images using polarization. The polarization color is controlled by changing
the total retardation of the birefringent materials. Various colors can be displayed without color filters, which canbe applied to color imaging device. There are various ways to control the polarization color. In this presentation,
we show how to control the polarization color.
Figure 1(a) shows the conventional optical arrangement. The angle between the transmission axis of a polarizer
and the retarder axis of a retarder film is 45°or 135°because the maximum transmittance is obtained at theseangles. Figure 1(b) shows the proposed optical arrangement. The angle between the transmission axis of apolarizer and the retarder axis of a retarder film can be varied, and up to four retarder films are stacked. Using this
proposed setup, we can display a high chroma image.
Figure 1(c) shows the composition the of polarization color display with stacking order dependence. Fourretarder films (films 1, 2, 3, and 4) are inserted between two crossed polarizers such that the retarder axes of theretarder films are 45˚, 0˚, 135˚, and 0˚, respectively. The retardation of films 1 and 3 are 140 nm. In thiscomposition, the displayed polarization color only depends on the retardation of film 2. By changing the positionof images 1 and 2, the displayed polarization color changes. Figure 1(d) shows the optical arrangement of astereoscopic imaging setup using polarization color. In general, stereoscopic imaging involves polarization, andpolarized glasses with orthogonal polarization (±45° linear polarization or circular polarization) are used. A
complementary color is observed with each eye when we apply this arrangement for viewing stereoscopic images
using polarization color. In our stereoscopic arrangement, the polarization axes of both eyes are fixed to θ =±22.5° (or θ = ∓67.5°) to separate the left-eye and right-eye images.

(a) General optical composition(b) Proposed optical composition 1(c) Proposed optical composition 2(d) Proposed optical composition 3

Fig. 1. Optical composition for viewing polarization color image

DHIP 2017

72

Inv21p-6

H.-J. Choi

Researches on effects of physiological depth cueson the visual discomfort of augmented reality displays
Hee-Jin Choi*, Hanul Lee, Minyoung Park, and Jaehee Seo
1
Dept. of Physics, Sejong University, Seoul 05006, Korea
Tel.:82-2-3408-3208, *E-mail: hjchoi@sejong.ac.kr
OCIS codes: (110.3000) Image quality assessment; (100.6890) Three-dimensional image processing.
Recently, there are fast progresses in the field of augmented reality(AR) to overlap a virtual image including
additional information to the object of interest by realizing a see-through optical system. Since the AR device canemerge the digital information with the objects in the real world, it attracts increasing attention for various
applications. However, there are still some bottlenecks to be overcome for the AR devices to become popular.
Among them, the human factor issue is one of the most important research subjects to be analyzed carefully. In
this paper, we introduce our researches on the effects of physiological depth cues which can be the potiential
causes of the visual discomfort of current AR displays[1].

ObjectObject80km/hAR image

AR image

The range ofclear perception

80km/hThe range ofclear perception

ObserverObserver80km/h

80km/h

80km/h

80km/hLeft eye’s view

Right eye’s view

Left eye’s view

Right eye’s viewFig. 1. Effect of physiological depth cues in current AR devices
We made the observer watch two images to be composed of odd/even half rows of a single digit number at
different image planes (an AR image plane and an object image plane) and guess what the number is. Then, we
measured the propotion of correct and the recognition time which the observer had consumed before making ananswer. In order to evaluate the effect of the convergence and accommodation separately, we analyzed the
response of the binocular viewing condition and monocular viewing condition respectively.
With the binocular viewing condition, the distance bewteen the two image planes had a positive correlation withthe recognition time whereas the propotion of correct decreases had a negative correlation. In contrast, there wasno significant correlation between them in the monocular viewing condition. Therefore, it can be concluded thatthe cue of convergence has a larger affection to the visual discomfort than the accommodation and it isrecommended to develop an improved AR devices to display the adapted AR images where the real object locates.
References
1. H. Lee, M. Park, J. Seo, and H.-J. Choi, "Analysis on the range of clear perception of an augment reality
devices by measuring the recognition time of the observerm," The 17th International Meeting on Information
Display(IMID 2017), Busan, Korea, paper P1-119, August, 2017

DHIP 201773

Inv22a-1

Y. Hayasaki

Volumetric Bubble Display
Yoshio Hayasaki & Kota Kumagai
Center for Optical Research and Education (CORE), Utsunomiya University
7-1-2 Yoto, Utsunomiya 321-8585, Japan
Tel.:+81-28-689-7114, E-mail: hayasaki@cc.utsunomiya-u.ac.jp
OCIS codes: (110.0110) Imaging systems; (300.0300) Spectroscopy; (110.1758) Computational imaging
Much attention has been paid to the development of three-dimensional volumetric displays in fields of optics andcomputer graphics, and it is a dream of we display researchers. They can render 3D graphics in real 3D space, andtherefore, a volume image can be observed from any surrounding viewpoints without the user having to wear any
special devices or experience physiological discomfort [1]. These optically-accessed volumetric displays have awide viewing angle because they require no physical connection between the light source and the display volume.
Therefore, reconfigurable and parallel connections are easily achieved, resulting in good accessibility and highdrawing speed to the voxels. We developed three kind of volumetric displays with laser-excited florescencevoxels[2], laser-produced plasma voxels[3], and laser-produced micorbubble voxels[4]. In this presentataion, we
focus a volumetric display using light-scattering voxels formed of microbubbles induced by focused femtosecond
laser pulses in high-viscosity liquid. This display is called as a volumetric bubble display.
Volumetric bubble display consisted of an amplified femtosecond laser source (Micra and Legend Elite
Duo, Coherent), a 3D beam scanner composed of a 2D galvanometer mirror (GM-1010, Canon) and varifocal lens(EL-10-30- Ci, Optotune), a liquid-crystal on silicon SLM (LCOS-SLM; X10468-02, Hamamatsu Photonics) for
holographic laser drawing, and glycerin in a glass cell. The femtosecond laser had a center wavelength of 800 nm,
a repetition frequency of 1 kHz, and a pulse duration of <100 fs. The galvanometer scanner changed the focus
position in the horizontal direction. A varifocal lens controlled the focus position in the axial direction. The 3D
focal position was changed by these devices to render the 3D graphics. The LCOS-SLM displayed Fourier CGHs
at a frame rate of 10 Hz. The Fourier CGHs were optimized by the optimal rotating angle method to generateparallel beams. The screen was glycerin sealed in a glass cell with dimensions 10 mm × 10 mm × 100 mm.
Figure 1(a) shows 3D bubble graphics viewed from different observation directions. These graphics
were rendered by scanning 100 2D outlines of cross-sectional images from ear to foot, and were illuminated by
the halogen lamp. The irradiation energy was 4.3 μJ. The volumetric graphics was successfully rendered by using
femtosecond laser-induced microbubbles. Figure 1(b) shows the bubble graphics illuminated by light of different
colors. The illumination light was emitted by a high-power full-color LED capable of outputting light of different
colors. The center wavelengths were 624 nm (red), 525 nm (green), and 470 nm (blue). The irradiation pulse
energy was 5.4 μJ. Although these results are monochrome graphics with different colors, it will be easy to form
full-color bubble graphics by changing the color of the illumination light.

Fig. 1 (a) Volumetric graphics of “Stanford bunny” rendered by femtosecond laser-induced microbubbles. (b) 2D
bubble graphics of “Dolphin” with illumination light having different colors.
References[1] B. G. Blundell and A. J. Schwarz, IEEE Trans. Vis. Comput. Graph. 8, 66–75 (2002).
[2] K. Kumagai, D. Suzuki, S. Hasegawa and Y. Hayasaki, Opt. Lett., 40, 3356–3359 (2015).
[3] Y. Ochiai, K. Kumagai, T. Hoshi, J. Rekimoto, S. Hasegawa, Y. Hayasaki, ACM Trans. Graph. 35, 1–14 (2016).
[4] K. Kumagai, S. Hasegawa and Y. Hayasaki, Optica 40, 298–302 (2017).

DHIP 201774

Inv22a-2

J. -H. Park

Accommodative optical-see-through near-to-eye displays using waveguide andholographic optical elements
Jae-Hyeung Park*, Seong-Bok Kim, Seok-Beom Ko, Kwang-Soo Shin, Yeon-Gyeong Ju, Dae-Yeol Park, andAskari Mehdi
Dept. of Information and Communication Engineering, Inha University, Incheon, 22212, Korea
Tel.:82-32-860-7432, E-mail: jh.park@inha.ac.kr
OCIS codes: (110.6880) Three-dimensional image acquisition; (100.6890) Three-dimensional image processing;(090.1760) Computer holography

Optical see-through near-to-eye displays (NEDs) are highly demanding in augmented reality (AR) applications.
Currently available NEDs usually present stereocopic views of a 3D scene. Despite of depth perception by thebinocular disparity, the individual image presented to each eye is 2D image at the conjugate plane of the display
panel where the eye accommodates, and thus there is vergence-accommodation mismatch problem. We havedeveloped several systems, solving this vergence-accommodation mismatch. One developed system is a
waveguide-type holographic NED. This system delievers a holographic 3D image generated by a spatial light
modulator (SLM) to the individual eye through the glass waveguide equipped with two holographic opticalelements (HOEs) couplers. The aberration caused by the asymmetric diffraction of the HOEs is pre-compensatedin the computer generated hologram (CGH) loaded in the SLM, presenting clear 3D images with true focal cues toeach eye on top of the optical-see-through view of the real environment.[1](a)(b)
Fig. 1. Waveguide type accommodative NEDs (a) holographic NED (b) Mawellian NED
A waveguide type Maxwellian display system has also been developed. In this system, the HOE works as thetransparent multiplexed concave mirrors to give always-focused images to each eye. The multiple spots in the eyepupil plane generated by the single HOE contributes to the enlargement of the eyebox, solving small eyebox
problem of conventoinal Maxwellian displays. We have also developed a technique to present the always-focused
images and the true 3D images at the same time by using CGH as the display contents of the SLM in theMaxwellian displays.[2] We expect this technique can be applied to wide range of applications of AR.
Acknowledgment
This work was supported by the Basic Science Research Program, National Research Foundation of Korea(NRF) [NRF-2017R1A2B2011084].
References
1. H.-J. Yeom, H.-J. Kim, S.-B. Kim, H. Zhang, B. Li, Y.-M. Ji, S.-H. Kim, and J.-H. Park, Optics Express 23(25),32025 (2015).
2. J.-H. Park, OSA Frontiers in Optics 2017 (FiO 2017), Washington, DC, USA, paper FW5C.3, (2017).

DHIP 201775

Unlimited depth of focus imaging is available by incoherent Fourier digital holography using a rotational
shearing interferometer. However, the image quality obtained by this method is not so high. To improve
Inv22a-3
the image quality, it is important to make the imaging property clear. In this paper, eﬀect of eachT. optical
Nomuraelement used in the interferometer on the image quality is investigated by numerical simulation, andappropriate parameters will be determined.
1 Introduction Incoherent holography without depth of fieldA technique to obtain an image of an object is required for observation of biological cells and inspection of industrial
products. In conventional optical imaging with a single
lens, the depth of field (DOF) is limitted by a point spread
Takanori Nomura1 and Takuya Matsuda2function 1(PSF) of the lens, and the image is blurred outside the DOF. This blur reduces its spatial resolution andFaculty of Systems Engineering, Wakayama University, Wakayama, Wakayama, Japan
prevents observation with highspatial resolution. E-mail:This is anom@sys.wakayama-u.ac.jp
problem in practical applications. Therefore, a techniqueTel.:81-73-457-8174,
2 enables us to obtain an image focusing on every object in deﬀerent axial positions is required. Unlimited DOF
which
Graduate School of Systems Engineering, Wakayama University, Wakayama, Wakayama, Japan
is available by incoherent Fourier digital holography using a rotational shearing interferometer 1) . However, the image
quality obtained by this method is not so high. To improve the image quality, it is important to make the imaging
propertyclear.
OCIS
codes:(090.1995) Digital holography; (110.1758) Computational imaging; (100.3195) InterferometricIn
thispaper, the eﬀect of each optical element used in the interferometer on the image quality is investigated byimaging
numerical simulation, and appropriate parameters such as the size of the optical element will be determined.
2

Principle

It iscommon to observe objects which exist at different depths by a microscope. However, it is impossible to
A rotational shearing interferometer 2, 3) is shown in Fig. 1. The right angle prisms 1 and 2 are slightly rotated atobserve all in-focus objects. To obtain all in-focus images, a number of methods have been proposed. In thisangles of θ/2 and -θ/2, respectively. The incoherent lightwave from an object passes through a band pass filter to be
paper, alternative method to obtain all in-focues image is introduced.
set temporally coherent. The lightwave is separated by a beam splitter. One of the lightwaves is rotated θ by the right
For pattern matching of incoherent objects, the use of the cosine transformation of an object have been
angle prism 1, and the other is rotated −θ by the right angle prism 2. Therefore, the angle of a total rotational shear
proposed1). The cosine transformation of an object is obtained by a rotational shearing interferometer. If theis 2θ. A lens is aligned in front of an image sensor to focus on the roofs of the right angle prisms. When the opticalpower distribution of a spatially incoherent object with a wavenumber k is given by P(x,y), the obtained intensity
path lengths of the two arms of the interferometer are equal, the intensity distribution of interference fringe (hologram)
distribution, incoherent hologram I(µ,n) obtained at a detector plane whose distance from an object is z, is given
I(µ, ν) is discribed asbyI(µ, ν) =

1
2

!! ∞
−∞

P(x, y)dxdy +

1
2

#
"
2 sin θ(−xν + yµ) dxdy,
P(x, y) cos k
z
−∞

!! ∞

(1)

(1)

where P(x, y) denotes the intensity distribution of an incoherent object. The magnification of the reconstructed image
is givenbywhere,
q denotes
the rotational shearing angle given by the interferometer. The distance z affects only themagnification of the Fourier transformation. Therefore, all focused images can be obtained by the inverse
2 sin θFourier transformation of an incoherent hologramM given
by , Eq. (1). The images shown in Fig. 1 are(2)the=kpreliminary experimental results of this method. In thez experiments, the object was a Chinese character
angleobject
prism 1 wasconsisting
displayedon a ofliquid
crystaldisplay
where kfour
and zsquares
denote thewavenumber
the object
wave
and thewhose
opticalbacklight was green LEDs.RightTheplaceddifferent
distances(210
andsensor
240 mmfromthe imageInsensor). The sizes of reconstructed images
pathatlength
betweenthe object
andmm
image
planes,respectively.
θ/2
are thedifferent.
However,they arefactcomponent
suggests theright handside of Eq.(1),the focused.
first term isThis
the biasand imaging without depth of focus based on aBand pass filter
hologramobtaineda rotational
shearing
interferometer.
the second
term isbythe
Fourier cosine
transformof P(x, y). By using theinverse Fourier transform, the image of the object is reconstructed from
Eq.(1). From Eqs.(1) and (2), the position of the object does not aﬀect
the DOF of the object but its magnification. Therefore, there is no limitof the DOF in the method.
It is thought that the image quality is aﬀected by the optical elements consisting of the interferometer. Namely, they are the numericalaperture (NA) of the lens in front of an image sensor, the optical transfer
function (OTF) of the lens, the spectral width of the band pass filter, andBeam splitter

Object(x,y)θ/2
Right angle prism 2

Lens
Image sensor(µ,ν)

Fig. 1 A rotational shearing interferometer.

(a)(b)
Fig. 1. Reconstructed images of incoherent holograms obtained by a rotational sharing interferometer.
The objects were placed at a distance of (a) 210 mm and (b) 240 mm.
More detailed discusssion of the reconstructed images including magnification and image quality will be given.
References
1. T. Nomura, K. Itoh, and Y. Ichinoka, Appl. Opt., 28(23), 4987 (1989).
2. K. Watanabe and T. Nomura, Appl. Opt., 54(1), A18 (2015).
3. T. Matsuda and T. Nomura, ISOM`17 Tu-J-10 (2017).

DHIP 201776

Inv22a-4

S. -W. Min

Recent researches for two type 3D screens:
Reflection-type and Transmission-typeSung-Wook Min* and Hyunsik Sung
Dept. of Inform. Display, Kyung Hee University, Dongdaemun-gu, Seoul 02447, Korea*E-mail: mins@khu.ac.kr
OCIS codes: (110.6880) Three-dimensional image acquisition; (100.6890) Three-dimensional image processing;(090.1760) Computer holography
The projection-type display system has been used in the display industry because the displaying region is enlarged
easily. However, in the projection-type display system, the projection image has low diverging angle due to thelimitation of exit pupil. Therefore, when we use the projection system, we need the diffuser as the screen forobserving image presented by the projector. The projection-type display system is often used in three-dimensional(3D) dispaly system due to its adavantages. However, the projection-type 3D dispaly system also has sameproblem for the limited field of view. So we cannot obseve 3D image without any screen. To resolve this probelm,
we use the diffuser in the projection-type 3D display system. But, this solution is not effective beacuse the diffuser
can help improve the visibiltity of image located on the screen, and other images is blurred. Therefore, we need
the new screen for the projection-type 3D display system, which is called 3D screen.
In previous research, the optical depth converter (ODC), consisted of two lens arrays, was proposed as
the screen in the projection-type integral imaging system [1]. The ODC can be used to resolve the pseudoscopic
problem in integral imaging system because the ODC arranges the 3D integrated images in the reverse order.
Besides, the ODC can retain the depth information in the space. Thanks to its characteristic, the ODC can be usedas the 3D screen of the projection-type 3D display system.
The 3D screen is divided into two types: reflection-type and transmission-type. The reflection-type 3Dscreen generally uses a lens array and a reflecting device as the equivalent system for the ODC. The reflectiontype 3D screen using the simple mirror has the problem that the image flipping occurs the reflected image by the
mirror after passing through the adjacent elemental lens. To resolve the problem, we use the retroreflector film,
which reflects the reflected light in the direction of the incident, in the reflection-type 3D screen. To optimize thereflection-type 3D screen using the retroreflector film, we analyze the distance between the retroreflector film andthe lens array [2]. The transmission-type 3D screen can be instrumented using ODC or adding other opticaldevices in the ODC. The ODC has same problem of the image flipping. To resolve this problem, we adapt the
micro hole-mirror array (MHA) in the transmission-type 3D screen. However, because it is difficult to fabricate
the MHA, and so we propose the new structure fabricated easily and name it the roof mirror array [3].
In this paper, to optimize the transmission-type 3D screen, we confirm the image simulation of the MHA
using Light Tools 8.3 and compare the imaging simulation results shown in Fig. 1 according to the incident angle.
In addition, we fabricate the proto-type the MHA to compare with the simulation results.

(a) 24 degree(b) 30 degree(c) 36 degree(d) 42 degree

Fig. 1. Image simulation results
Acknowledgment
This work was supported by the National Research Foundation of Korea(NRF) grant funded by the Korea government(MSIT) (No.2011-0030079)

References
1. S-W. Min et al, “Analysis of an optical depth converter used in a three dimensional integral imaging system,” Appl. Opt. 43(23), 4539-4549 (2004).
2. Y. M. Kim et al, “Projection-type integral imaging system using a three-dimensional screen composed of a lens array and a retroreflector film,” Appl. Opt.
56(13), F105-F111 (2017)
3. S-W. Min et al, “Recent research about 3D screen,” in the Sixth Japan-Korea workshop on Digital Holography and Information Photonics. (OpticalSociety of Japan & Optical Society of Korea, Sapporo, 2016)

DHIP 201777