Distortions of the laser radiation phase in the case of pulsed bleaching of an artificial fog

An experimental investigation was made of phase distortions of probe beams during bleaching of a small-volume artificial fog with pulsed CO₂ laser radiation of microsecond duration. The phase was determined employing an amplitude-division two-beam interferometer. Confirmation was obtained of the theoretically predicted increase in the gas density as a result of explosive evaporation of particles resulting in focusing of radiation and the lifetime of this effect was determined. Experimental data were obtained on the kinetics of the refractive index during bleaching and it was found that the thermal losses due to explosive evaporation of drops under conditions of complete bleaching of a fog were considerably less than the heat of evaporation.