Multi-photon temperature profile modeling in solids during powerful pulse laser irradiation

This paper is a description of the analytical model developed to study the temperature distributions in solid materials heated by powerful laser pulses. The calculations are based on a three-dimensional model of heat diffusion in solids using the integral transform method. Our model takes into account the one-, two-, three- and four-photon absorption. Specific results are presented for an application of the model to a InSb sample heated with a pulsed CO2 laser. The results indicate that (i) the two-, three-photon absorption does produce detectable temperature variation but the four-photon absorption may produce detectable variation only at very high laser beam intensity; (ii) the surface absorption coefficient does play a very important role in temperature distribution; (iii) the field temperature depends on the duration of the pulse.