Abstract

The application of infrared spectroscopies for combustion diagnostics offers an exciting new opportunity to measure a wide range of polyatomic molecular species. The ability to measure low concentrations of many species important in combustion chemistry has been limited to a great extent to molecules that that can be probed using laser-induced fluorescence in the visible and ultraviolet spectral regions. Over the past several years our group has been investigating the use of infrared spectroscopies in an effort to greatly expand the polyatomic molecules that can be probed using laser diagnostics. This effort has benefited from advances in laser technology as well as the development of new spectroscopic approaches. The work discussed in this paper makes use of a tunable single-mode optical parametric oscillator system to provide high resolution rovibrational spectra. Degenerate four-wave mixing (DFWM) and cavity ringdown laser absorption spectroscopy (CRLAS) are the two spectroscopic techniques investigated.

© 1996 Optical Society of America