Publication Date:
2015-11-24
Description:
We present a mid-infrared pulsed cavity ring-down spectroscopy (CRDS) setup based on difference frequency mixing of a tunable dye laser pumped by a Nd:YAG laser and the residual 1064 nm pulse in a temperature-stabilized lithium niobate (LiNbO 3 ) crystal. The performances of such a spectrometer have been investigated by studying the absorption spectrum of methane around 3 µm at room temperature. Our results show a minimum detectable absorption coefficient of 5 × 10 −8 cm −1 . Our approach combines the excellent sensitivity of CRDS with the wide tunable range of difference frequency generation (DFG) with a dye laser. However, the relatively low resolution of this spectrometer prevents the quantification of methane in a wide pressure range. To our knowledge, we report here the first realization and application of a pulsed DFG-based CRDS experiment used for sensitive trace gas detection.
Print ISSN:
0946-2171
Electronic ISSN:
1432-0649
Topics:
Physics
