[Citation] International Display Workshop 2023 (IDW'23): 3D Systems and Applications 2023 (3DSA2023), Niigata,
paper 3DSAp1-2, 1304-1306 (2023.12.7, IDW '23 Outstanding Poster Paper Award).

Denisyuk-type Wavefront Printer Developed for Printing LargeScale Display CGVH
Yuki Takemura1, Hirohito Nishi1, Kyoji Matsushima1
k493099@kansai-u.ac.jp (Y. Takemura)
1 Department of Electrical and Electronic Engineering, Kansai University

Yamate-cho 3-3-35, Suita, Osaka 564-8680, Japan.
Keywords: CGH, volume hologram, wavefront printer, Denisyuk-type optical system
ABSTRACTThe latest status of development is presented in a novel
type of wavefront printer called the Denisyuk-type
wavefront printer. The introduced 4K high-definition SLM
and improved optics facilitates fabrication of large-scale
full-parallax CGVHs with a wide viewing angle.
1

Introduction
Computer-generated hologram (CGH) is a hologram
created by generating interference fringe of virtual object
using a computer. The calculated fringe pattern is printed
with a very fine printing equipment, such as e-beam orlaser lithography systems. However, the holograms
obtained by the ordinary printing systems are so-called‘thin holograms’ because the ordinary printing systems
print two-dimensional fringe pattern. As a result, theprinted CGHs exhibit chromatic aberration whenilluminating with white light. On the other hand, the fringeof volume holograms, sometimes called ‘thick’ hologram,has a three-dimensional structure and thus gives
wavelength selectivity. Accordingly, volume holograms
can avoid the issues of thin holograms and reconstruct 3D
images with a white light illumination.
In a conventional manner, fabrication of computergenerated volume holograms (CGVH) requires two steps:
creation of a master hologram using lithography, andtransfer of the holographic image onto the recording
material such as photopolymer [1]. A Wavefront printer isthe equipment that makes it possible to perform theseprocesses in a single step [2-5]. In the conventional
wavefront printers, light emitted from a coherent lightsource is commonly split into two arms using a beam
splitter: beams for a write field recorded in the recording
material and reference field. The beam for the write field
is commonly split again in order to use an LCOS spatiallight modulator (SLM) for producing the write field, i.e.,wavefront. As a result, intensity of the write field
decreases to one-eighths of the output of the light source,in general. This reduction leads to longer exposure timeand increases vulnerability to vibrations.
A Denisyuk-type wavefront printer is proposed toovercome the problem of reduction of the write field [6,7]. This type of wavefront printer not only avoids
reduction of the write field but also reduce the number of
optical components used in the system. Therefore, theprinter features more simple, compact and resistant tovibrations during printing.
In this paper, we present the latest status of thedevelopment of the Denisyuk-type wavefront printer,
where a 4K SLM is introduced to increase the size andviewing angle of full-parallax high-definition (FPHD)CGVHs. In fact, we demonstrate an FPHD-CGVH whose
size is 12.3 cm × 9.0 cm. The viewing angle is 33° inboth horizontal and vertical directions. Not only apresentation on the wavefront printer but also actualFig. 1 Optical setup of the Denisyuk-type wavefront printer.

Table 1 Specifications of SLM.
ModelJD7714 (Jasper Display)

Number of pixels

4,094 × 2,400

Pixel pitches [µm]3.74 × 3.74

Display size [mm2]15.31 × 8.97

Table 2

Parameters of the printed CGVH.

Design wavelength [nm]532

Number of tiles
Total number of samples ofwrite field
Sampling interval of write
field [µm]32 × 400.935 × 0.935

Size [mm2]122.5 × 89.7

Viewing angle [deg]33.1 × 33.1

Settling time [s]3Exposure time [s]0.25

Photopolymer

Bayfol®HX200

printed CGVHs will be presented in the poster or exhibitionroom.
2Fig. 2 Printing by tiling.

131,008 × 96,000

Denisyuk-type wavefront printer2.1 Principle
Denisyuk hologram is a hologram, where subjects are
illuminated by light transmitted through the recording
material. The hologram fringe is generated by opticalinterference between the object field reflected by thesubjects and the light entering the recording material. As aresult, the optical system is very simple because of nobeam splitting. Since the generated fringe has a 3D
structure, the recorded hologram is a volume hologram.
2.2 Optical setup
Figure 1 and Table 1 show the optical setup of theDenisyuk-type wavefront printer where a 4K SLM
introduced in this work. In the optical system, the output ofthe laser light source is converted into a collimated beamusing the spatial filter and collimator lens. The collimatedbeam is then shaped into a rectangular beam using avariable rectangular aperture. The rectangular beam
passes through a photopolymer sheet used for therecording material and illuminates 4K LCOS SLM after
transmitting the beam expander. The write field generated
by the 4K SLM irradiates the photopolymer almost
perpendicularly to the surface after passing through a 4-f
optical system with the bandpass filter. In this optical setup,since 𝑓1 = 400 mm and 𝑓2 = 100 mm, the effective
sampling interval of the write field is reduced to 0.935 µm.
2.3 Tiling small CGVHs
The space-bandwidth product of the write field producedby the SLM is very small. Therefore, the tiling technique iscommonly used in wavefront printers to increase the sizeof holograms. As shown in Fig. 2, a large-scale wavefieldof the write field is first calculated and then divided into
small sub-fields (tiles) that can be generated by the SLM.
The sub-fields are printed sequentially as moving thephotopolymer using an automatic stage. This allows us
to reconstruct the whole large-scale wavefield.
3

Printing large-scale CGVH
The 3D scene of the printed CGH is shown in Fig. 3.
A checkerboard wallpaper is placed behind the surface
model of the Venus statue. The full-parallax wavefield of
the 3D scene is calculated with the polygon-based
method and the silhouette method for occlusion
processing [8].

Fig. 3 The 3D scene of the printed CGVH.
The parameters of the printed CGVH are presented inTable 2. The total number of samplings of the write field
is more than 12.5 billion. The size of the printed CGVH
is approximately 123 mm × 90 mm. This is achieved by
combination of 32 × 40 tiles. The sampling interval of thewrite field is reduced to one-fourth of the SLM pixel
pitches by the 4-f setup in Fig. 1. To avoid vibration
caused by moving the photopolymer by the stage, asettling time between printing sub-tiles is set to 3
seconds. The total printing time of the CGVH wasapproximately 2.5 hours.
4

Optical reconstruction of printed CGVH
The photographs of optical reconstruction of theprinted FPHD-CGVH are shown in Fig. 4, where a pigtail
white LED is used for the illumination light source. We
can confirm apparent occlusion when moving theviewpoints because of the large size and wide viewing
angle of the printed CGVH.
5Conclusion
We reported the latest Denisyuk-type wavefront printer,
where 4K high-definition SLM is installed and the improved
optics achieves fabrication of 12.5 G-sampled large-scale
CGVHs with a viewing angle more than 30°.
This work was supported by Japan Society for thePromotion of Science (JSPS) KAKENHI 22H03712.
References[1] O. Kunieda and K. Matsushima, “High-quality fullparallax
full-color
three-dimensional
image
reconstructed by stacking large-scale computergenerated volume holograms,” Appl. Opt. Vol. 58, No.
34, G104-G111 (2019).
[2] W. Nishii and K. Matsushima, “A wavefront printerusing phase-only spatial light modulator for producing
computer-generated volume holograms,” SPIE Proc.
Vol. 9006, 90061F (2014).
[3] T. Yamaguchi, O. Miyamoto, and H. Yoshikawa,Fig. 4[4]

[5]

[6]

[7]
[8]

“Volume hologram printer to record the wavefrontof three-dimensional objects,” Opt. Eng. Vol. 51(7),075802 (2012).
R. Oi, P. Y. Chou, B. J. Jackin, K. Wakunami, Y.
Ichihashi, M. Okui, Y. P. Huang, and K. Yamamoto,“Three-dimensional reflection screens fabricated byholographic wavefront printer,” Opt. Eng. Vol. 57(6),061605 (2018).
Y. Kim, E. Stoykova, H. Kang, S. Hong, J. Park, J.
Park, and J. Hong, “Seamless full color holographic
printing method based on spatial partitioning ofSLM,” Opt. Express Vol. 23, No. 1, 172-182 (2017).
T. Saito and K. Matsushima, “Basic study of a
wavefront printer using Denisyuk-type opticalsystem,” 3D-Conference (2017), in Japanese.
K. Matsushima, Introduction to Computer
Holography, Sect. 15.4.4 (Springer, 2020).
K. Matsushima, S. Nakahara, “Extremely highdefinition
full-parallax
computer-generated
hologram created by the polygon-based method”,
Appl. Opt. Vol. 48, pp. 54–63 (2009).

Optical reconstruction of the printed FPHD-CGVH. The pictures are taken from different
viewpoints.