Design and Implementation of Si-based Optical Discrete Fourier Transformer

• Project/Area Number: 16K06345
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Communication/Network engineering
• Research Institution: University of Yamanashi
• Principal Investigator: HANAWA Masanori 山梨大学, 大学院総合研究部, 教授 (90273036)
• Research Collaborator: KODAMA Takahiro
• Project Period (FY): 2016-04-01 – 2019-03-31
• Project Status: Completed (Fiscal Year 2018)
• Budget Amount: ¥4,810,000 (Direct Cost: ¥3,700,000、Indirect Cost: ¥1,110,000); Fiscal Year 2018: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2017: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2016: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000)
• Keywords: 光符号分割多重 / 光離散フーリエ変換器 / シリコン光チップ / フーリエ符号化 / シリコン基板 / 試作 / フォトニック結晶導波路型光遅延線 / マルチプロジェクトウェハー / シリコン細線導波路内光強度モニタ / シリコン細線導波路 / 光学的離散フーリエ変換 / フォトニック結晶導波路 / 光遅延線 / 光直交周波数多重 / 光信号処理 / シリコン光集積回路

Outline of Final Research Achievements

This research aimed to implement optical discrete Fourier transformers (ODFT) for optical code division multiplexing (OCDM). Four-chip ODFT's were designed and implemented on Si-substrates and characterized. The coupling loss of the Si-substrates were 20 dB and the extinction ratio of the ODFT was 5.8 dB in this trial. At the same time, numerical evaluations on downsizing optical delay lines based on photonic crystal waveguides (PCW) and compensation of amplitude slope due to loss of optical delay lines were performed. By incorporating a specially designed charp-rod structure the coupling loss between a Si-nano wire and a PCW was estimated around 1.0 dB comparing with 5.9 dB without the chirp structure. Also the digital compensation of the amplitude slope resulted in 0.3 dB improvement in power penalty.

Academic Significance and Societal Importance of the Research Achievements

OCDM 方式は，符号器・復号器に光ファイバ型回折格子や石英導波路などのこれまでの実装技術では，伝送速度の向上に限界がきている．研究代表者はこれまでに，フーリエ符号化の導入，多値変調方式の導入，ディジタルコヒーレント光受信技術の導入などで本方式のブラッシュアップを行ってきたが，この結果，特に多値変調信号の導入には，従来よりも格段に高精度な符号器・復号器が必要であることが明らかになっている．本課題で，Si 基板型符号器・復号器を実現することで高精度を図り，伝送速度の向上を目指した．

Research Products

• [Journal Article] Collective compensation of an inter-chip intensity discrepancy for a 4ch QPSK FE-SOCDM system with Si-based ODFT and electrical DFT (2018)
  • Author(s): Kodama Takahiro、Nukanobu Tomoki、Miyazaki Tatsuya、Hanawa Masanori
  • Journal Title: Optics Express Volume: 26 Issue: 20 Pages: 25909-25909
  • DOI: 10.1364/oe.26.025909
  • Peer Reviewed / Open Access
• [Presentation] フーリエ符号化同期光符号分割多重伝送に向けた離散フーリエ変換器のシリコン光チップによる実装 (2018)
  • Author(s): 塙 雅典，小玉崇宏，吉野陽紀，宮崎達也
  • Organizer: IEICEフォトニックネットワーク研究会
  • Invited
• [Presentation] Siフォトニック結晶導波路型光遅延線のパルス伝搬解析 (2017)
  • Author(s): 吉野陽紀,小玉崇宏,塙 雅典
  • Organizer: 2017年電子情報通信学会総合大会
  • Place of Presentation: 名城大学天白キャンパス（愛知県名古屋市天白区）
  • Year and Date: 2017-03-24
• [Presentation] Silicon-based Optical Discrete Fourier Transformer for Optical Code Division Multiplexing & Optical Labeling (2017)
  • Author(s): Masanori Hanawa
  • Organizer: 12th International Workshop on Optical Signal Processing and Optical Switching, Guilin, China
  • Int'l Joint Research / Invited
• [Remarks] 山梨大学研究者総覧
  • URL: http://erdb.yamanashi.ac.jp/