Feasibility study of terahertz-frequency arbitrary electromagnetic waveform generation

2022 Fiscal Year Final Research Report

• Project/Area Number: 21K18730
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 21:Electrical and electronic engineering and related fields
• Research Institution: Kyushu University
• Principal Investigator: Kato Kazutoshi 九州大学, システム情報科学研究院, 教授 (10563827)
• Project Period (FY): 2021-07-09 – 2023-03-31
• Keywords: 光電変換デバイス / テラヘルツ波 / フォトミキシング / アレー集積

Outline of Final Research Achievements

A technology for generating arbitrary electromagnetic waveforms with THz-frequency components has been developed. Specifically, a chip that integrates an array of photoelectric conversion devices connected to antennas designed for different center-gain frequencies was devised. In the design, the shape of each antenna was optimized. For the prototype fabrication, a 2D-3D conversion structure was devised and realized for the connection between the microstrip line and coplanar line, which is essential for the connection to the antenna.A THz self-delay interferometer was designed and constructed to evaluate THz electromagnetic waveforms by splitting the THz wave to be measured, adding a delay to one of the THz waves, and then combining the two waves.
The developed device was used to generate THz-frequency repetitive electromagnetic pulse waves, and its applicability to 1 THz-class wireless communications was examined based on waveform evaluation.

Free Research Field

光エレクトロニクス

Academic Significance and Societal Importance of the Research Achievements

本研究の要素技術一つである光波形生成では、繰り返し300GHzの光パルス波生成および自己相関計による波形観測に成功している。もう一方の要素技術である光電変換では、アレー化した同じ特性を持つ複数のフォトダイオードにより100GHz～700GHzの電磁波生成と空間合波による強度増大を実現している。
本研究は、光波形生成と、アレー状フォトダイオードでの光電変換という、それぞれ独創的研究を、帯域補完型アレーという新奇コンセプトのもとで融合し任意電磁波形生成に挑戦するものである。またこの成果を用いて、未知領域であるサブピコ秒領域での物質やデバイスの電磁波応答という新分野開拓の可能性を秘めた探索研究である。