The change of thermal properties under the exposure to fs-laser pulses

Abstract

We start with a short introduction of some newer thermodynamical approaches to the description of nonequilibrium processes related to the interaction of short laser pulses with matter. Then we shall use the example of electronic thermal conductivity to show why the equations usually derived in standard solid state theory have to be reconsidered. This is mandated by the loss of local thermal equilibrium, the nonstationarity, and the enhanced contribution from electronelectron scattering. Based on Boltzmann's equation we derive an expression for the thermal conductivity with new qualitative and quantitative properties. These results are supported by comparison with experiments.

Fs-laser pulse damage of semiconductors

“…In this model, three coupled differential equations are solved numerically for the space and time-dependent density and temperatures. The question of validity and applicability of the temperature concept on short time scales is briefly discussed in a second paper given of this conference 24 . Basically, the model deals with coupled Boltzmann's equations in the relaxation time approximation to describe the development of the electron density and the electron and phonon temperature generated by short laser pulses.…”