Nonlinear pulse propagation in the presence of evaporating aerosols

A set of coupled, nonlinear differential equations is developed describing the propagation of a pulsed, quasi-monochromatic beam of electromagnetic radiation in a medium containing vaporizing aerosols. Spatiotemporal distortions in the beam are produced as a result of radiation-induced changes in the absorption and scattering coefficients as well as in the angular spread of the phase function. The irradiance distribution function of the pulse is governed by a time-dependent transfer equation in the small-angle approximation. Numerical solutions to the equations are obtained for the case of pulse propagation through a cloud of vaporizing water droplets. It is found that significant spatiotemporal distortion of the pulse accompanies enhanced aerosol vaporization.