Dual wavelength 3.2-mu m source for isotope ratio measurements of (CH4)-C-13/(CH4)-C-12

作者：Abe Masashi^*; Kusanagi Satomi; Nishida Yoshiki; Tadanaga Osamu; Takenouchi Hirokazu; Sasada Hiroyuki

来源：Optics Express, 2015, 23(17): 21786-21797.

DOI：10.1364/OE.23.021786

Difference frequency generation using one 1.58-mu m and two 1.06-mu m distributed feedback Bragg-grating laser diodes and a ridge-type PPLN alternately provide two 3.2-mu m coaxial waves resonant with individual isotopic transitions separated by 13 cm(-1). The nu(3) band R(6) A(2) allowed transition of (CH4)-C-13 and the nu(3) band R(6) A(2) weakly allowed transition of (CH4)-C-12 are an ideal pair for isotope ratio measurements. The (CH4)-C-13/(CH4)-C-12 isotope ratio is determined for three sample gases with a relative uncertainty of 0.7 parts per thousand, and it is confirmed that the temperature dependence is smaller than the uncertainty.

• 出版日期2015-8-24