AEROSOL-LASER NONLINEAR INTERACTIONS - A REVIEW.

The properties and the magnitudes of optically induced forces on ultrafine aerosols in a high-power laser beam are reviewed to demonstrate the feasibility of self-induced optical waveguide in aerosol media. The aerosol-lens and aerosol mirror effects and the nature of optical beam deformation by aerosols are discussed as functions of the particle size, refractive index, laser output frequency and intensity, and atmospheric ambient pressure. Theoretical calculations on such interacting mechanisms as the photophoresis, radiation pressure, electrostrictive and gravitational forces, and their effects on the modulation of the aerosol concentration, and thus the refractive index inside the laser beam are discussed. Results obtained from these theoretical models show that under atmospheric pressure, thermophoretic force dominates and the 'thermal booming' (i. e. , self de-focusing) effect is important. At upper atmosphere, electrostrictive force takes over and self-focusing laser beams exist in aerosols.