Abstract

Tunable diode lasers are an excellent source of narrow linewidth (< 0.001 cm^-1) infrared radiation which can be rapidly scanned to perform fast, high resolution absorption spectroscopy. With the advantages of high sensitivity and high resolution, tunable diode laser spectroscopy is a potentially powerful diagnostic technique for probing infrared active flame species whenever a line-of-sight method is suitable. In the late 1970's, Hanson and co-workers introduced infrared diode laser spectroscopy as a combustion diagnostic technique. Quantitative CO [1,2] and NO [2,3] concentrations were determined from the absorption measurements and temperatures [4] were determined from the relative intensity of two closely spaced ro-vibrational transitions originating from different vibrational levels.

© 1992 Optical Society of America