[14a-B2-1~11] 3.9 Terahertz technologies

△ [14a-B2-3] Gas sensing by terahertz-evanescent wave spectroscopy using the LiNbO₃ optical waveguide

〇(M2)Yuki Kimura¹, Zun Tada¹, Koji Suizu¹, Isao Morohashi², Yoh Ogawa², Shinya Nakajima², Norihiko Sekine², Iwao Hosako² (1.Chiba Inst.Tech., 2.NICT.)

Keywords:terahertz-evanescent wave spectroscopy

In this study, we demonstrated the gas sensing by the terahertz-evanescent wave spectroscopy, using an optical waveguide structure to reduce requirement for the excitation light sources.The Dual-wavelength CW light sources for the terahertz-wave generation(100 mW of average power) was coupled to the optical waveguide.After wavelength division of dual-wavelength light using the CWDM, the intensity difference of dual-wavelength light was measured using balance detector.In this measurement, pure nitrogen gas was encapsulated to the container filled with 100% humidity.When pure nitrogen gas was encapsulated to the container in which the optical waveguide stored, the output of balance detector changed.The result indicates that the gas sensing can be performed using the terahertz-evanescent wave spectroscopy.