Degenerate four-wave mixing spectroscopy and spectral simulation of C-2 in an atmospheric pressure oxy-acetylene flame

The d (3) Pi(g)<->a (3) Pi(u) Swan bands of C-2 have been recorded with high resolution using DFWM in the nearly Doppler free, phase conjugate geometry. C-2 was probed in a standard oxy-acetylene welding flame with excellent signal-to-noise ratio and spectral resolution, Theoretical spectra were simulated and fitted directly to the complex overlapping spectra. The good agreement obtained shows that DFWM holds promise to become a robust and reliable tool for flame thermometry. Current theories of DFWM are reviewed in context of the present work and advantages and disadvantages of the technique are discussed. (C) 1997 American Institute of Physics.