Detection of methane with mid-infrared polarization spectroscopy
We report on the application of polarization spectroscopy in the midinfrared spectral region for the detection of methane by probing its asymmetric ro-vibrational transitions. Tunable infrared laser radiation, near 3.4 mum, was obtained from difference-frequency generation in a LiNbO3 crystal. Infrared polarization spectroscopy (IRPS) spectra of the P, Q and R branches of the nu(3) band, recorded
