Mode control of intense terahertz wave source based on angular momentum carried by spoof plasmon

2023 Fiscal Year Final Research Report

• Project/Area Number: 22K14617
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 30020:Optical engineering and photon science-related
• Research Institution: Niigata University
• Principal Investigator: Annaka Yuta 新潟大学, 工学部, 教室系技術職員 (20835699)
• Project Period (FY): 2022-04-01 – 2024-03-31
• Keywords: テラヘルツ波発生 / 疑似表面プラズモン / 電子ビーム

Outline of Final Research Achievements

Analysis of spoof surface plasmon modes is conducted to realize efficient terahertz-wave generation based on a Cherenkov interaction between an electron beam and spoof surface plasmons. Firstly, I perform an experiment to excite spoof surface plasmons in a cylindrical corrugated waveguide by combining a plasmonic structure. Next, I perform experiment to generation of terahertz wave and examine the spoof plasmon modes excited by the electron beam. I successfully generate a kilowatt power terahertz wave in a frequency rage from 0.30 to 0.35 THz. I also devise a method to analysis the excited spoof plasmon modes by asymmetry of terahertz radiation pattern. These research achievements were published in five papers and one oral presentation.

Free Research Field

テラヘルツ波発生

Academic Significance and Societal Importance of the Research Achievements

テラヘルツ波は電波と光の中間の周波数の電磁波である。通信や医療応用、非破壊検査など様々な応用が期待されており、高効率なテラヘルツ波源の開発が重要である。本研究では疑似表面プラズモンと呼ばれる電磁波モードの励起により1kWの出力電力を持つ大電力テラヘルツ波発生に成功している。また異なる軌道角運動量を運ぶ複数の疑似表面プラズモンモードを同時に励起したときテラヘルツ波放射の非対称な強度分布が生じることが分かった。この放射の非対称性はテラヘルツ電磁波モードの解析の指標となるほか、指向性テラヘルツ波送電などの応用が考えられる。