Research and development of ultra-high speed and low-driving voltage spatial light modulators

• Project/Area Number: 24560427
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Electron device/Electronic equipment
• Research Institution: Chubu University
• Principal Investigator: WAKITA KOICHI 中部大学, 生命健康科学部, 教授 (20301640)
• Co-Investigator(Kenkyū-buntansha): TAKAHASHI Makoto 中部大学, 工学部, 教授 (10236317)
• Project Period (FY): 2012-04-01 – 2016-03-31
• Project Status: Completed (Fiscal Year 2015)
• Budget Amount: ¥5,460,000 (Direct Cost: ¥4,200,000、Indirect Cost: ¥1,260,000); Fiscal Year 2014: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2013: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000); Fiscal Year 2012: ¥2,340,000 (Direct Cost: ¥1,800,000、Indirect Cost: ¥540,000)
• Keywords: 高速 / 低電圧駆動 / 室温励起子吸収 / 高純度 / 厚い空乏層 / 電気吸収効果 / 電気光学効果 / 空間光変調器 / 低電圧 / 電界吸収変化 / 電界屈折率変化 / 光強度変調 / 低消費電力 / 高速動作 / 高消光比 / 屈折率制御 / 波面制御 / 並列処理 / 励起子吸収 / フランツ・ケルデッシュ効果 / 空間光変調

Outline of Final Research Achievements

For realizing the ultra-high speed and ultra-parallel optical processing, ultra-high purity GaAs epitaxial layers have been grown by liquid-phase epitaxy and clear exciton absorption and its large red-shift associated with applied voltage have been observed at room temperature. Large on-off ratio larger than 20dB by less than 10 V and subnano sec responce have been demonstrated and estimated. These data overcome reported data (1000V and a few msec response) and indicate the possibility of next generation spatial light modulator (SLM) in place of liquid crystal SLMs and magnetic resistance SLMs.
A large refractive index change (about 2 times larger than reported data) associated with observed large electroabsorption has been estimated based on the Kramers- Kroenig relation-ship.

Research Products

• [Journal Article] Excitonic refractive index change in high purity GaAs modulator at room temperature for optical fiber communication network (2015)
  • Author(s): Durga Prasad Sapkota, Madhu Sudan Kayastha, Koichi Wakita
  • Journal Title: International J. of Electrical, Computer, Electronics and Communication Engineering Volume: 9 Pages: 191-194
  • Peer Reviewed / Open Access
• [Journal Article] Electric field effects on exciton in the shape of transmission spectra in high-purity GaAs at room temperature (2014)
  • Author(s): Durga Prasad Sapkota, Madhu Sudan Kayastha, Koichi Wakita
  • Journal Title: Opticaｌ and Quantum Electronics Volume: 46 Issue: 2 Pages: 203-210
  • DOI: 10.1007/s11082-014-9901-7
  • Peer Reviewed / Open Access
• [Journal Article] Proposed model pf electric field effects in high-purity GaAs at room temperature (2014)
  • Author(s): Durga Prasad Sapkota, Madhu Sudan Kayastha, Makoto Takahashi, Koichi Wakita
  • Journal Title: Optics and Photonics Journal Volume: 4 Pages: 99-103
  • Peer Reviewed / Open Access
• [Journal Article] Synthesis of carbon fibers with branched nanographene sheets for electrochemical double layer capacitor application (2014)
  • Author(s): M. Matsushima, Kalita Golap, K. Kato, M. Noda, H. Uchida, K. Wakita, M. Umeno and M. Tanemura,K. Wakita, M. Umeno and M. Tanemura
  • Journal Title: Journal of Nanoscience and Nanotechnology Volume: 14 Pages: 2614-2619
  • Peer Reviewed
• [Journal Article] Low temperature synthesized graphene by surface wave plasma CVD as effective oxidation barrier (2014)
  • Author(s): Kalita Golap, M. E. Ayhan, D. Ghimire, S. Shinde, K. Wakita, M. Umeno and M. Tanemura K. Wakita, et al.,
  • Journal Title: Corrosion Scienece Volume: 78 Pages: 183-187
  • Peer Reviewed
• [Journal Article] Synthesis of hexagonal graphene on polycrystalline Cu foil from solid camphor by atomic chemical vapor deposition (2013)
  • Author(s): Subash Sharma, Golap Kalita, Muhammed Ermre Ayhan, K. Wakita, Masayoshi Umeno, Masaki Tanemura
  • Journal Title: Journal Material Science Volume: 48 Pages: 7036-7041
  • Peer Reviewed
• [Journal Article] Plastic forming of high-Tc YBa2Cu3O7-x bulk superconductors (2013)
  • Author(s): M. Takahashi, K. Sawada, H. Ishikawa, T. Omi, S. Ohkido, M. Tahashi, and K. Wakita
  • Journal Title: J. Am. Chem. Soc.., Volume: 96 Pages: 1713-1717
  • Peer Reviewed
• [Journal Article] Improved Photovoltaic Properties of Heterojunction Carbon Based Solar Cell (2013)
  • Author(s): Sudip Adhikari, M. S. Kayastha, D.C. Ghimire, H. R. Aryal, S. Adhikary, T. Takeuchi, K. Murakami, Y, Kawashimo, H. Uchida, K. Wakita, M. Umeno
  • Journal Title: Journal of Surface Engineered Materials and Advanced Technology Volume: 3 Pages: 178-183
  • Peer Reviewed
• [Journal Article] Effects of Temperature and Well Composition on Threshold Current Density for Compressive Strained-Layer AlxGayIn1-x-yAs Single Quantum Well Lasers (2013)
  • Author(s): Durga Prasad Sapkota, Madhu Sudan Kayastha, Koichi Wakita
  • Journal Title: 電気学会論文誌Ｃ Volume: 133 Pages: 1139-1144
  • Peer Reviewed
• [Journal Article] Effect of electric field on exciton in high-purity GaAs epilayer measured at room temperature (2013)
  • Author(s): M. S. Kayastha, K. Wakita, et al.,
  • Journal Title: Electronics Letters Volume: 49 Pages: 57-59
  • Peer Reviewed
• [Journal Article] Photoinduced charge transfer composite of graphene oxide and ferrocene (2013)
  • Author(s): Kalit Golap, K. Wakita, et al.,
  • Journal Title: Physical Chemistry Chemical Physics (RSC Journal), Volume: 15 Pages: 1271-1274
  • Peer Reviewed
• [Journal Article] Analysis of linewidth enhancement factor for compressively strained AlGaInAs and InGaAsP quantum well lasers (2013)
  • Author(s): D. P. Sapkota, K. Wakita, et al.,
  • Journal Title: Optical and Quantum Electronics Volume: 45 Pages: 35-43
  • Peer Reviewed
• [Journal Article] Low temoerature growth of graphene film by microwave assisted surface wave plasma CVD for transparent electrode application (2012)
  • Author(s): Kalit Golap, K. Wakita, et al.,
  • Journal Title: RSC Advance (paper) Volume: 2 Pages: 1825-2820
  • Peer Reviewed
• [Journal Article] Formation of graphene-containing porous carbon film for electrical double-layer capacitor by pulsed plasma chemical vapor deposition (2012)
  • Author(s): M. Matsushima, K. Wakita, et al.,
  • Journal Title: Japanese Journal of Applied Physics Volume: 51
  • NAID: 210000140440
  • Peer Reviewed
• [Journal Article] Synthesis of graphene by surface wave plasma chemical vapor deposition from camphor (2012)
  • Author(s): Kalit Golap, K. Wakita, et al.,
  • Journal Title: Physica Status Solidi A, Vol.1-4, pp. Volume: 1-4 Pages: 2510-2513
  • Peer Reviewed
• [Presentation] 高純度GaAsエピ膜を用いた大きな電界屈折率変化 (2015)
  • Author(s): 脇田紘一、サプコタ D.P.、吉田拓矢、高橋 誠
  • Organizer: 応用物理学会秋季学術学講演会
  • Place of Presentation: 名古屋国際会議場
  • Year and Date: 2015-09-24
• [Presentation] The preparation and characterization of metal chalcogenide thin film by the electrodeposition (2015)
  • Author(s): M. Takahashi,T. Nagaya, T. Suzuki, S. Ohkido, M. Tanashi, K. Wakita
  • Organizer: ISPlasma 2015/IC-PLANTS 2015
  • Place of Presentation: Nagoya Univ.(Aichi, Nagoya)
  • Year and Date: 2015-03-27 – 2015-03-31
• [Presentation] Excitonic refractive index change in high purity GaAs modulator at room temperature for optical fiber communication network (2015)
  • Author(s): Durga Prasad Sapkota, Madhu Sudan Kayastha, Koichi Wakita
  • Organizer: World Academy of Science, Engineering and Technology(WASET)
  • Place of Presentation: Dubai, UAE
  • Year and Date: 2015-02-26 – 2015-02-27
• [Presentation] Growth of Graphene Films by Thermal CVD from Adamantane (2014)
  • Author(s): T. Yoshida, M. Noda, S. Yamaguchi, H. Uchida, M. Umeno, and K. Wakita
  • Organizer: E-MRS/MRS-J
  • Place of Presentation: IDEC Yokohama (Kanagawa, Yokohama)
  • Year and Date: 2014-12-10 – 2014-12-12
• [Presentation] Graphene-amorphous carbon composite films for photovoltaic solar cell (2013)
  • Author(s): Sudip Adhikari, H. Uchida, K. Wakita, M. Yasubayashi, Umeno
  • Organizer: PVSEC-23
  • Place of Presentation: Taipei
• [Presentation] Synthesis of continuous graphene on metal foil for flexible transparent electrode application (2013)
  • Author(s): Kalit Golap, K. Wakita, et al.,
  • Organizer: Proceeding of IEEE 5th International Nanoelectronics Conference (INEC), pp. 281-284
  • Place of Presentation: Singapore
• [Presentation] Room temperature excitonic electro-absorption effect for high-speed and low-driving voltage spatial light modulators (2012)
  • Author(s): M. S. Kayastha, K. Wakita, et al.,
  • Organizer: 2012 International Conference on Solid State Devices and Materials(SSDM), PS-7-12
  • Place of Presentation: Kyoto
• [Presentation] Large-area CVD graphene as transparent electrode for efficient organic solar cells (2012)
  • Author(s): Kalit Golap, K. Wakita, et al.,
  • Organizer: Proceeding of 38th IEEE photovoltaic specialists conference, pp. 003137 – 003141
  • Place of Presentation: Austin
• [Presentation] Chemical vapor deposition of large area graphene for electronics device application (2012)
  • Author(s): Kalit Golap, K. Wakita, et al.,
  • Organizer: IUMRS-ICA 2012
  • Place of Presentation: Busan
• [Presentation] Experimental and theoretical study of excitonic electroabsorption in high-purity GaAs at rooom temperature (2012)
  • Author(s): D. P. Sapkota, K. Wakita, et al.,
  • Organizer: IEEE Photonics Global Conference
  • Place of Presentation: Singapore
• [Presentation] Large-area CVD graphene as transparent electrode for efficient organic solar cells (2012)
  • Author(s): Kalit Golap, K. Wakita, et al.,
  • Organizer: Proceeding of 38th IEEE photovoltaic specialists conference
  • Place of Presentation: Austin
• [Remarks] 次世代光伝送用光素子の研究 「中部大学研究者紹介２０１５」
  • URL: http://www3.chubu.ac.jp/collaboration/.