Article ID Journal Published Year Pages File Type
5431060 Journal of Quantitative Spectroscopy and Radiative Transfer 2006 10 Pages PDF
Abstract

Tunable near-infrared radiation has been generated in a rubidium titany1 phosphate (RTP) crystal by employing non-collinear difference-frequency mixing (DFM) technique. The input radiation sources are Nd:YAG laser radiation and its second harmonic pumped dye laser radiation. For the generation of 2.0 radiation, the maximum value of the conversion efficiency (quantum) obtained in the process is 49% from the dye (0.6945 μm) to the infrared (2.0 μm) radiation in the 7.9-mm-long crystal. The generated tunable mid-infrared radiation has been used to measure the number density, absorption cross-section and minimum detectable concentration of methane gas in its 2ν3 band in a multi-pass cell at 30.075 Torr pressure. The number density and column density of the methane molecules are found to be 1.068×1018 cm−3 and 3.02×1021 cm−2, respectively, whereas the minimum still-detectable concentration at 1.658 μm wavelength is estimated to be 4.523×1017/cm3.

Related Topics
Physical Sciences and Engineering Chemistry Spectroscopy
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