Aerosol clearing model for a high-energy laser beam propagating through vaporizing media

We describe the clearing phenomenon that occurs when a continuous wave (cw) high-energy laser beam, incident upon a cloud of hygroscopic droplets, vaporizes these droplets. We consider the case when the incident wavelength is greater than the average droplet radius. The model of F. A. Williams [Int. J. Heat Mass Transfer 8, 575 (1965)] is used to describe the vaporization of a single droplet. The propagation of the laser beam is described by the radiative transfer equation in one dimension. We establish the existence of an ‘‘inertial’’ characteristic time ti that it takes for evaporation to be established in an aerosol cloud. Agreement of our model with a set of experimental data on vaporizing fog is demonstrated.