Effect of pump-laser linewidth on noise in single-pulse coherent anti-Stokes Raman spectroscopy temperature measurements

When N(2) is used as the probe molecule in a stable premixed propane-air flame near 2100 K, the standard deviation in single-pulse coherent anti-Stokes Raman spectroscopy (CARS) temperature measurements is shown to decrease by 20% as the pump-laser linewidth increases from </=0.02 to about 0.7 cm(-1). This effect is shown to be independent of the signal level at the detector array over the range considered. An instrument function that is useful in CARS convolution calculations is also presented.