CARS (Coherent Anti-Stokes Raman Spectroscopy) Measurements of Combustion. 1. Precision of Thermometry

摘要

Nitrogen coherent anti-Stokes Raman spectroscopy (CARS) spectra obtained from the post flame gases in a flat flame burner were analyzed and the accuracy of the resulting temperatures is discussed. It is shown that referencing on the time-averaged signals gives accurate spectra comparable to theoretical ones by eliminating the effects of low frequency modulation of the broadband dye laser. Referencing on single pulse measurements gives correct average temperatures but cannot eliminate the influence of high frequency dye laser noise. Both full and quick fitting methods are applied to the determination of temperatures and the results are compared and evaluated.