Dual–pump CARS for the simultaneous detection of N2, O2 and CO in CH4 flames

Abstract

AbstractThe application of a modified dual‐pump CARS set‐up for the simultaneous determination of temperature and N2, O2 and CO concentration is demonstrated. This technique offers numerous advantages, which are discussed in detail and presented for the investigation of a partially premixed flame. In comparison with a standard vibrational CARS set‐up, consisting of one Nd:YAG laser and one broadband dye laser together with a single spectrometer and camera, only one additional narrowband dye laser is needed. By shifting the spectral profile of the broadband dye laser providing the excitation profile, N2 and CO were excited simultaneously from a single narrowband–broadband laser combination as in an usual CARS set‐up with degenerate pump wavenumbers. Additionally, oxygen was excited using the same broadband laser but another narrowband laser in a dual‐pump CARS configuration. The technique presented is not limited to the three species investigated here. Copyright © 2002 John Wiley & Sons, Ltd.