High-resolution absorption measurements of CO2 were made in a heated static cell and in the combustion region above a flat-flame burner for the development of an in situ CO2 combustion diagnostic based on a distributed-feedback diode laser operating near 2.0 µm. Calculated absorption spectra of high-temperature H2O and CO2 were used to find candidate transitions for CO2 detection, and the R(50) transition at 1.997 µm (the ν1 + 2ν2 + ν3 band) was selected on the basis of its line strength and its isolation from interfering high-temperature water absorption. Measurements of spectroscopic parameters such as the line strength, the self-broadening coefficient, and the line position were made for the R(50) transition, and an improved value for the line strength is reported. The combustion-product populations of CO2 in the combustion region above a flat-flame burner were determined in situ to verify the measured spectroscopic parameters and to demonstrate the feasibility of the diode-laser sensor.
© 2001 Optical Society of America
Original Manuscript: May 23, 2000
Revised Manuscript: August 28, 2000
Published: February 20, 2001
Michael E. Webber, Suhong Kim, Scott T. Sanders, Douglas S. Baer, Ronald K. Hanson, and Yuji Ikeda, "In situ combustion measurements of CO2 by use of a distributed-feedback diode-laser sensor near 2.0 µm," Appl. Opt. 40, 821-828 (2001)