2021年第82回応用物理学会秋季学術講演会

講演情報

一般セッション(口頭講演)

4 JSAP-OSA Joint Symposia 2021 » 4.6 Terahertz Photonics

[11p-N404-1~9] 4.6 Terahertz Photonics

2021年9月11日(土) 13:00 〜 16:00 N404 (口頭)

紀和 利彦(岡山大)、中嶋 誠(阪大)

13:30 〜 14:00

[11p-N404-2] Terahertz wave generation and detection in GaAs crystals enhanced by using tapered parallel plate waveguides as focusing optics

Masahiko Tani1、Ramon delos Santos2、Takashi Furuya1、Hideaki Kitahara1、Elmer Estacio3、Joselito Muldera1、Mary Clare Escano1、Miezel Talara1、Michael Bakunov4 (1.Univ. of Fukui、2.Ateneo Univ.、3.Univ. of the Philippines、4.Univ. of Nizhny Novgorod)

キーワード:terahertz wave, GaAs, tapered parallel plate waveguide

GaAs has excellent potential as a nonlinear optical material for the generation and detection of terahertz (THz) waves with the excitation at the optical communication wavelengths, where cost-effective, compact, and stable femtosecond lasers are available as a pump source. Cherenkov phase-matching angle in GaAs is around 12°, which is substantially smaller than in other representative nonlinear optical crystals. Due to the small Cherenkov angle, a long interaction length of the optical and THz beams is possible in GaAs and no coupling optics is required to couple the generated THz waves to free-space radiation. In this paper, the authors report the results of their research and development of THz emitters and detectors using GaAs as a nonlinear optical medium and tapered parallel plate waveguides (TPPWGs) as a focusing device for THz waves. We present a fully GaAs-based THz-TDS scheme that offers broadband (~3 THz) THz generation and detection and the dynamic range as high as 106. In this scheme, the noncolinear Cherenkov phase-matching is implemented in ~6-10-mm long GaAs crystals. Using TPPWG allows for improving the scheme performance by a factor of ~2-3.