ROTATIONAL AND VIBRATIONAL TEMPERATURE DETERMINATION BY DFWM SPECTROSCOPY

Using the DFWM technique we determined rotational and vibrational temp eratures of NaH molecules in a dynamical system consisting of NaH, Na, H and H-2 for several heat-pipe oven temperatures. We applied a new w ay to determine the dependence of the DFWM signal I-c(int) on the powe r of the transition dipole moment mu without previous knowledge of the temperature. The revealed dependence is I(c)(int)proportional to mu(4 ). In this case the laser intensities were found to be of the same ord er as the saturation intensity in accordance with simple DFWM theory. A usual Boltzmann plot was employed for the determination of the relev ant rotational temperatures, which displayed higher values than the ov en temperature.