HEAT-TRANSPORT IN METALS IRRADIATED BY ULTRASHORT LASER-PULSES

Different regimes of heat propagation in metals irradiated by subpicos econd laser pulses are studied on the basis of a two-temperature diffu sion model. Analytical solutions for the heat conduction equation, cor responding to the different temperature dependences of the electron th ermal conductivity, are obtained. It is shown that in case of a strong electron-lattice nonequilibrium, the heat penetration depth grows lin early with time, and the heat propagation velocity decreases with incr easing laser fluence. Investigations of this ''counterintuitive'' regi me of heat propagation are performed.