ON THE THEORY OF PS AND SUB-PS LASER-PULSE INTERACTION WITH METALS .1. SURFACE-TEMPERATURE

A model is proposed describing the interaction of short laser pulses w ith metals. It is shown that a generalized nonlocal heat flow in time leads to an equation of heat conduction with additional terms involvin g the time derivative of both the laser intensity and the coupling of the electrons to the phonons. The importance of the coefficient of hea t exchange for the temperature distribution in metals and the differen t influence of its main parts, the electron phonon coupling and the av eraged square phonon frequencies, is pointed out. For a laser pulse le ngth of 1 ps the electron and phonon surface temperatures for Al, Cu, Nh and Pb are evaluated using a double temperature model with a nonloc al heat flow. This is compared with the results of a local heat flow a pproach and with the conventional theory.