I report the first detection, to my knowledge, of molecular absorption over a wide spectral range by Zeemanmodulated high-resolution Fourier-transform spectrometry. The theoretical line shape is derived and compared with the actual results obtained for the 1−0 band of NO near 1900 cm−1. The experimental conditions are simple. Classical absorption of a usual white light source, no polarizing optics, and a small magnetic field characterize the recording system. Only the paramagnetic NO molecules are detected. This clearly shows that the method should facilitate the detection of unstable paramagnetic species in plasma sources. Magnetic modulation is not the only type of modulation that could have been used. For instance, the Stark effect, instead of the Zeeman effect, could have been utilized.
© 1986 Optical Society of America
G. Guelachvili, "Selective detection of paramagnetic species by high-information Fourier-transform spectrometry," J. Opt. Soc. Am. B 3, 1718-1721 (1986)