A new polarization modulation Zeeman method combined with high resolution Fourier transform spectroscopy is described. It selectively detects the paramagnetic species produced in a plasma under a constant magnetic field. The polarizing optics is convenient and easily covers wide spectral ranges. NO absorption and N2O, NO emission spectra are reported. With a magnetic field of the order of 560 G and a 40-cm long discharge tube, the P and R lines of the 1—0 band of NO around 5 µm are observed up to J = 28.5 whereas the much more intense N2O lines are not detected. Unexplained line shapes of the first Q2 lines of NO are reported. A comparison with a recent frequency modulation Zeeman method coupled with high resolution Fourier transform spectroscopy is given.
© 1989 Optical Society of America
Mohammed Elhanine, Robert Farrenq, and Guy Guelachvili, "Polarization modulation high resolution Fourier transform spectroscopy," Appl. Opt. 28, 4024-4029 (1989)