An Efficient and Compact Difference-Frequency-Generation Spectrometer and Its Application to 12CH3D/12CH4 Isotope Ratio Measurements

Sensors

Kiyoshi Tsuji²  Hiroaki Teshima¹  Hiroyuki Sasada¹ 

[1] SENTAN, Japan Science and Technology Agency/Sanbancho 5, Chiyoda-ku, Tokyo 102-0075, Japan;Department of Environmental Science and Technology, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology/4259, Nagatsuta-cho, Midori-ku, Yokohama, 226-8502, Japan; E-Mail:

关键词: isotope ratio;    methane;    laser spectroscopy;    difference frequency generation;    waveguide PPLN;   

DOI  :  10.3390/s100706612

来源: mdpi

【 摘 要 】

We have developed an efficient and compact 3.4 μm difference-frequency-generation spectrometer using a 1.55 μm distributed feedback (DFB) laser diode, a 1.06 μm DFB laser diode, and a ridge-waveguide periodically poled lithium niobate. It is continuously tunable in the 30 cm⁻¹ span and is applied to ¹²CH₃D/¹²CH₄ isotope ratio measurements. The suitable pair of ¹²CH₃D ν₄ ^pP(7,6) and ¹²CH₄ ν ₂+ν₄ R(6) F₁⁽¹⁾ lines enabled us to determine their isotope ratio with a precision repeatability of 0.8‰ using a sample and a working standard of pure methane with an effective signal averaging time of 100 ms.

【 授权许可】

CC BY   
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