The feasibility of the application of harmonic saturated spectroscopy to molecular detection in the infrared regime was investigated. Experimental measurements using SF6 as a model gas were performed with a CO2 laser photoacoustic molecular vapor detector operating in the 9–11-µm portion of the infrared regime. These experiments demonstrated the negligible loss of absolute sensitivity, the maintenance of a characteristic readily identifiable absorption profile, and the ability to scale with laser intensity in the proper conditions. Our work demonstrates the importance of a laser modulation waveform that is completely devoid of spatial asymmetries for the realization of the full potential of this method.
© 1985 Optical Society of America
Charles M. Klimcak and Jerry A. Gelbwachs, "Harmonic saturated spectroscopy applied to molecular photoacoustic detection," Appl. Opt. 24, 247-253 (1985)