Investigation of the kinetics of electrostrictive and thermal changes in the refractive index of glasses exposed to laser radiation

Green's dynamic tensor is used to solve dynamic equations for an equilibrium of an isotropic solid exposed to the electrostrictive and thermal action of laser radiation. An analysis is made of the kinetics of electrostrictive and thermal changes in the refractive index Δn. It is found that steady-state values of Δn are established within the time t = 5r₀/v_l (r₀ is the beam radius, v_l is the longitudinal velocity of sound) and that, after the end of a pulse, tensile electrostrictive stresses develop on the beam axis. Radiation focusing conditions are determined for which the beam cross section can be considered to be constant in investigations of electrostrictive and thermal mechanisms of action of laser radiation on glass.