Influence of melting-cristallization processes on shape of photoacoustic pulse during laser-irradiation of highly absorbing condensed media

The analysis of shape of the photoacoustic pulses during melting and subsequent crystallization under the action of the nanosecond laser pulses with $\lambda_\nu=1.06\,\mu m$ on the highly absorbing condensed media has been performed. The influence of the jump variations of the thermophysical and optical characteristics of the matter, the radiation intensity and the surface evaporation on shape of the photoacoustic pulses has been considered. It is found, that the qualitative changes of the pulse shape are connected mainly with the jumps of density, absorptivity and enthalpy.