Abstract

The potential of resonant degenerate four-wave mixing (DFWM) as a sensitive, coherent diagnostic probe of combustion species has recently been demonstrated.¹,² Similar to coherent anti-Stokes Raman spectroscopy (CARS), DFWM generates a highly collimated, narrow bandwidth signal beam that allows remote detection, requires minimal optical access, and provides excellent immunity to background luminosity. However, since DFWM is typically performed with resonant radiation, it offers much greater sensitivity than CARS, permitting trace-species detection. While DFWM has been extensively studied in the context of phase conjugation,³ comparatively little has been reported on the development of DFWM for quantitative molecular spectroscopy.

© 1992 Optical Society of America