Nonsteady-state self-interaction in a medium with striction nonlinearity

An analytic and numerical investigation is made of the self-focusing of a w ave beam allowing for the inertia of the nonlinear response of the medium d escribed by an acoustic type of equation. Some characteristics of the dynam ics of self-interaction of the wave fields are analyzed in the paraxial opt ics approximation and the self-similar structures and space-time instabilit y of a plane wave are considered. The stages of instability buildup, struct ure formation, and the establishment of a steady state are studied numerica lly. (C) 2000 MAIK "Nauka/Interperiodica".