[19a-PA2-1~26] 3.9 Terahertz technologies

[19a-PA2-22] Gas sensing by terahertz evanescent wave spectroscopy using proton exchange waveguide

〇Hiroki Komori¹, Naoki Ejima¹, Ryoichi Takada¹, Koji Suizu¹, Isao Morohashi², Yoh Ogawa², Shinya Nakajima², Norihiro Sekine², Iwao Hosako² (1.Chiba Institute of Tech., 2.NICT.)

Keywords:Terahertz wave, difference frequency generation, spectroscopy

In this study, we demonstrated gas sensing by terahertz evanescent wave spectroscopy.A proton exchange LiNbO₃ waveguide was used to reduce the noise due to polarization fluctuations.Absorption line at around 1.92THz of water vapor was used for the measurement sample.The intensity difference of dual wavelength light was measured using balance detector.Light intensity change by water vapor absorption around 1.92THz could be measured.The absorption spectrum of water vapor was successfully measured.