THERMOMETRY OF AN OXY-ACETYLENE FLAME USING MULTIPLEX DEGENERATE 4-WAVE-MIXING OF C-2

Thermometry of an oxy-acetylene flame using multiplex Degenerate Four- Wave Mixing (DFWM) of C-2 is demonstrated. More than 100 rotational tr ansitions in the d(3) Pi(g) <-- a(3) Pi(u) (0, 0) Swan band of C-2 cou ld be recorded simultaneously by use of a pulsed, broad bandwidth ''mo deless'' laser. Temperatures were inferred by fitting temperature-depe ndent synthetic spectra of single- or multiple-shot averaged spectra. The strength and reliability of recorded signals together with the lar ge number of rotational lines observed suggest that multiplex DFWM is a promising technique for minor species detection and for temporally r esolved temperature measurements in luminous environments. Factors inf luencing the accuracy and precision of single-shot thermometry using t he technique are discussed.