Generation of acoustic oscillations by short laser pulses in metals

摘要

Nonlinear plasma effects important for femtosecond-scale heating dynamics are considered. It is shown that heating of electrons due to the inverse bremsstrahlung absorption of high-power short-pulse laser radiation results in parametric generation of ion-acoustic waves. The range of wave numbers where the amplitude of the ion-acoustic oscillations increases by more than an order of magnitude is determined. A self-similar description of electron and phonon kinetics in metals with a sharp gradient of the electron temperature is developed. It is shown that the Cherenkov generation of nonequilibrium phonons results in suppression of the electron heat flux and rapid disintegration of the metal lattice.