Harmonic saturated spectroscopy applied to molecular photoacoustic detection

Abstract

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