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

作者：Tsuji Kiyoshi^*; Teshima Hiroaki; Sasada Hiroyuki; Yoshida Naohiro

来源：Sensors, 2010, 10(7): 6612-6622.

DOI：10.3390/s100706612

• isotope ratio
• methane
• laser spectroscopy
• difference frequency generation
• waveguide PPLN

We have developed an efficient and compact 3.4 mu m difference-frequency-generation spectrometer using a 1.55 mu m distributed feedback (DFB) laser diode, a 1.06 mu m 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 (CH3D)-C-12/(CH4)-C-12 isotope ratio measurements. The suitable pair of (CH3D)-C-12 nu(4) P-p(7,6) and (CH4)-C-12 nu(2)+nu(4) R(6) F-1((1)) lines enabled us to determine their isotope ratio with a precision repeatability of 0.8 parts per thousand using a sample and a working standard of pure methane with an effective signal averaging time of 100 ms.

• 出版日期2010-7