Abstract

Spatial averaging is a potential problem in the application of coherent anti-Stokes Raman spectroscopy (CARS) to combustion diagnostics when varying temperatures and composition are present at spatial scales smaller than the typical 1–2-mm spatial resolution of CARS. The observed CARS spectrum is then a mixture of the hot and cold components. We show that simulated, spatially averaged spectra, generated by the incoherent addition of intensities, can be significantly different from those obtained by the coherent addition of the electric field amplitudes of the component spectra. The analyses of these simulated, spatially averaged CARS spectra demonstrate that the use of theoretical CARS spectra, generated by the addition of intensities of the hot and cold components of a binary gas mixture, can lead to errors in the estimated flame temperatures.

© 1996 Optical Society of America

Evaluation of two different gas temperatures and their volumetric fraction from broadband N₂ coherent anti-Stokes Raman spectroscopy spectra

A. Thumann, T. Seeger, and A. Leipertz
Appl. Opt. 34(18) 3313-3317 (1995)

Noise in single-shot broadband coherent anti-Stokes Raman spectroscopy that employs a modeless dye laser

D. R. Snelling, R. A. Sawchuk, and T. Parameswaran
Appl. Opt. 33(36) 8295-8301 (1994)

Experimental comparison of single-shot broadband vibrational and dual-broadband pure rotational coherent anti-Stokes Raman scattering in hot air

Thomas Seeger and Alfred Leipertz
Appl. Opt. 35(15) 2665-2671 (1996)

Simultaneous vibrational and pure rotational coherent anti-Stokes Raman spectroscopy for temperature and multispecies concentration measurements demonstrated in sooting flames

Christian Brackmann, Joakim Bood, Per-Erik Bengtsson, Thomas Seeger, Martin Schenk, and Alfred Leipertz
Appl. Opt. 41(3) 564-572 (2002)

Comparison of gas temperatures measured by coherent anti-Stokes Raman spectroscopy (CARS) of O₂ and N₂

Thomas A. Reichardt, Paul E. Schrader, and Roger L. Farrow
Appl. Opt. 40(6) 741-747 (2001)