Study On The Thermal Effect In The Interaction Of The Laser Radiation With Matter

The thermal analysis of the interaction of the laser with the matter is one of the most important physics phenomena after the laser irradiates the targets. The laser-induced heating will lead to the temperature raise of the material, the heat diffusion, heat expansion and the thermal stress damage. If the laser energy is accumulated enough in the metal or the plastic material, some parts on the surface of the material will melt or evaporate. Thus we can take the advantage of the laser to drill the holes, cut, ablate the material and so on. Therefore the study of the thermal effect during the interaction of the laser radiation with matter forms the basis of the laser processing, the technology of laser heat treatment and the laser damage and so on. For some typical problems on laser heating, the thermal models have been built and the approximate analytical expressions to the heat diffusion equation have been obtained based on some certain assumptions and the boundary conditions. But the closed-form solutions are only applicable to the simpler situations and the results obtained are also approximate. The numerical simulation is more flexible and is able to deal with the more complicated problems. As long as the physical models describing the process of the ablation are reasonable, we can get the appropriate results. In this paper, the numerical calculations of the temperature raise in the photoelectric detectors illuminated by the long pulses laser and during ablation on metal under the ultrashort pulses laser are separately performed. Our central work and some conclusions are obtained as follows:1 , In consideration of the multilayered construction of the detectors and based on the thermal conduction equation, the temperature raise distribution of an InSb (PV) detector and a HgCdTe (PC) detector irradiated by continuous laser pulses are both numerically calculated using a 1-D model of heat conduction and by means of the implicit schemes difference expression. The relationship between the temperature raise and the laser power density or the irradiation time and the effects of heat conductivity and thickness of glue on heat recover time are discussed. Also the laser...