「様式３」

プロジェクト番号	  P-2１

Development of Infrared sensor based on 3D photonic crystal[1] Organization
Leader：Prof. Junko Morikawa（Tokyo Institute of Technology）
Representative：Prof. Vygantas Mizeikis
Research Institute of Electronics, ShizuokaUniversity, Japan）	  Participants：
Prof. Kestutis Staliunas(Universitat Politecnica de Catalunya (UPC),Fisica i Enginyeria Nuclear, Barcelona, Spain)
Dr. Mangirdas Malinauskas (Vilnius
University, Department of Quantum Electronics)
Prof. Saulius Juodkazis (Centre of Microphotonics,Swinburne University of Technology, Melbourne,Australia)
Prof. Kamen Kanev (Research Institute ofElectronics, Shizuoka University, Japan)[2] Research progressThis project is aimed at development of micro-scale
infra-red (IR) sensor for detection and imaging
applications. Traditionally, IR sensors are implemented
using i)solid-state devices based on narrow-band gap
semiconductors, or ii) bolometric devices. While (i) has
high speed, but needs cryogenic conditions for highsensitivity operation, (ii) allows uncooled operation, but its
sensitivity is lower, and response speed is also low due tohigh thermal mass. Here we aim to develop asuper-compact uncooled IR bolometric detector ensuringboth high sensitivity at room temperature and fast
response time. Such a device may offer considerable
advantages in cost and operational convenience, e.g.,higher reliability, reduced power consumption, smaller
size and reduced weight, as well as multispectral response
capability, while sacrifice in performance is minimal. The
micro-scale IR sensing device is based on a recently
proposed new principle for micro-scale thermal imaging,which exploits temperature-dependent reflectance (atvisible wavelengths) of a 3D photonic crystal (PhC)

structure.
Realization of this goal requires coordinated efforts inseveral areas of research, namely nanophotonics,
micro-/nano-fabrication, thermal imaging, and polymer
science. As a first step during the first year ofimplementation of this project, a mini workshop wasorganized on January 23, 2014 at Research Institute ofElectronics, Shizuoka University. The workshop wasattended by participants of the project, experts in therelevant fields, and was open for students and researchersinterested in these fields.
The presentations and discussions during the workshop
were centered on the following topics:
1) Physical mechanism of IR sensitivity ofphotonic crystals and its proof-of-principle
experimental implementation (V. Mizeikis)
2) Enhancement of optical absorption in photonic
crystals with chirped lattice period (K. Staliunas)
3) Tailoring of optical micro-/nano-structures andphotonic crystals by direct laser write technique(M. Malinauskas)4) Femtosecond laser fabrication of micro- andnano-photonic devices (S. Juodkazis)
5) Thermal and optical properties of bulk andstructured photoresists (J. Morikawa)[3] Results(3-1) Research results

Photonic crystals (PhC) are dielectric materials withperiodic refractive index modulation along one two, or
three dimensions, and a forbidden photonic band gap(PBG) for electromagnetic optical waves. In the PBG
spectral region light cannot enter the PhC, and strong
spectral reflectivity peak is observed in the PBG
wavelength range, whose central wavelength iscomparable and directly proportional to the PhC lattice
period. External factors, for example pressure or heat,capable of modifying the PhC lattice period will lead toFig. 1. Bolometric sensing with photonic crystals:
proportional swelling of the PhC lattice due to IR
absorption and heating (bottom) leads to spectral shift of
PBG reflectance peak (top). By monitoring change in thevisible reflectivity spectrum, detection of IR radiation ispossible.

spectral shift of the PBG region.
We have developed a concept of PhC based IR sensor
illustrated in Fig. 1. This concept is based on IR
sensitivity of a natural PhC structure – blue wing ofMorpho butterfly – observed and reported previously inthe literature (Nature Photonics 6, 195 (2012)). The
proposed PhC structure should be built from a material
that has strong IR absorption, and a high coefficient ofthermal expansion (CTE). External IR radiation absorbedby the PhC, may induce thermal expansion of the PhC
lattice, and lead to the corresponding spectral shift of thePBG reflectance peak. Thus monitoring the change of
PhC reflectance sat visible wavelengths allows one todetect IR radiation.
The first step towards realization of this new principle isto fabricate a PhCs structure exhibiting structural colorand strong optical reflectance at visible wavelengths. Thiswas achieved using Direct Laser Write (DLW) method in
photoresist illustrated in Fig. 2(a). DLW allows rapid
prototyping of 3D PhC structures with various latticegeometries and parameters by exploiting two-photon
photopolymerization induced in the focal spot of tightly
focused femtosecond laser beam, and scanning of the focal
spot to draw complex 3D PhC structures. This method isFig. 2. Fabrication of 3D photonic crystals by DLW
technique in photoresist (a), realization of controllable
structural color in photonic crystals fabricated by DLW(b).

highly suitable for tailoring of 3D photonic crystals, and will
be used to realize the structures required for this study. Using
this approach we have prepared PhC samples with 3D
woodpile architecture. High reliability and resolution of thefabrication technique allowed us to realize structural color in
the fabricated structures as illustrated in Fig. 2(b). Woodpile
PhC structures had a lateral lattice period of 0.9µm, afootprint size of (40x40) µm2 and consisted of 30 layers.
Optical reflectance images shown in the figure illustrate
bright structural color, and its controllable variation from redto green when PhC lattice parameters are varied during thefabrication. Next steps of our study will involve search ofthermal and IR sensitivity of the structural color.

(3-2) Ripple effects and further developments
Exchange of scientific expertise between the participants
was very helpful for coordination of experimental andtheoretical work towards the goal of this project. Also, it
has contributed to strengthening of domestic andinternational collaboration at Research Institute ofElectronics (RIE) of Shizuoka University. In addition,
participants of the workshop (Prof. K. Staliunas, Prof. S.
Juodkazis, and Dr. M. Malinauskas) also attended the2014 International Workshop on Advanced Nanovision

Science organized by RIE on January 20-21, 2014, where
they contributed oral presentations.
Another important	  ripple effect of this collaboration wasdecision by all participants to collaborate in preparation of
joint application for a larger international project partiallyoverlapping with the topic of the present project.
Enhancement of optical absorption in photonic crystals is
a new way to boost sensitivity of IR detectors.
Consequently, the participants decided to work on grant
proposal tentatively entitled “Stopped light in photonic
crystals for substantial enhancement of the efficiency ofinfrared detectors” for funding by NATO Science for
Peace and Security Programme. Work on this proposal
is currently in progress, and will likely be also joined byadditional researchers from RIE and Shizuoka University.
In conclusion, the joint work of all participants and themini-workshop conducted within the present project has
broadened existing domestic and international researchcollaborations at RIE, and opened new venues for futurecollaborations.
[4] Achievements
Journal article:(1) V. Mizeikis et al., “Realization of Structural Color by
Direct Laser Write Technique in Photoresist”
JLMN-Journal of Laser Micro/Nanoengineering 9, 42-45(2014).

Conference presentation:(2) S. Juodkazis, “Femtosecond laser fabrication: fromcuriosity to industrial applications” Saulius Juodkazis,
2014 International Workshop on Advanced Nanovision
Science, Jan. 20-21, Hamamatsu Campus, Shizuoka
University (2014).
(3)
M.
Malinauskas,“Ultrafastlaser
3D
micro/nano-fabrication of polymers - applications in
microoptics and biomedicine”, 2014 International
Workshop on Advanced Nanovision Science, Jan. 20-21,
Hamamatsu Campus, Shizuoka University (2014).
(4) K. Staliunas “Beam focusing by flat mirrors” (Invitedtalk), 2014 International Workshop on Advanced
Nanovision Science, Jan. 20-21, Hamamatsu Campus,
Shizuoka University (2014).

Travelling report
Name:
Affiliation:
Period of time:
Destination:
Purpose:Name of receiver:Name:
Affiliation:
Period of time:
Destination:
Purpose:Name of receiver:Name:
Affiliation:
Period of time:
Destination:
Purpose:Name of receiver:Prof. Saulius Juodkazis
Centre of Microphotonics, Swinburne University of Technology, Melbourne, Australia
2014.01.20-01.30
Shizuoka University, JapanTo carry out a joint research, plan the future collaboration, participate and report previously
obtained results. To attend Cooperative Research Workshop “Development of Infrared Sensors Based on 3D Photonic crystals” and2014 International Workshop on Advanced Nanovision Science.
Prof. Vygantas Mizeikis
Dr. Mangirdas Malinauskas
Vilnius University, Department of Quantum Electronics
2014.01.19-01.25
Shizuoka University, JapanTo carry out a joint research, plan the future collaboration, participate and report previously
obtained results. To attend Cooperative Research Workshop“Development of Infrared Sensors Based on 3D Photonic crystals” and2014 International Workshop on Advanced Nanovision Science.
Prof. Vygantas Mizeikis

Prof. Junko Morikawa
Tokyo Institute of Technology
2014.01.23
Shizuoka University, JapanTo plan the future collaboration, participate and report previously obtained results. To attend 2014
To attend Cooperative Research Workshop “Development of Infrared Sensors Based on 3D
Photonic crystals”
Prof. Vygantas Mizeikis