Research On Thermal And Mechanical Damage In Optical Glass Induced By Laser

Thermal conduction characteristics and temperature field characteristics of optical glass induced by gaussian beam were investigated, on the base of which, the transient distribution of temperature field and thermal stress field characteristics caused by pulse beam and the damage threshold were simulated and analyzed.Based on the thermal conduction equations, the mechanism of laser-induced thermal and stress damage of optical glass were studied by means of theoretical analysis and numerical calculations. The transient distribution of laser-induced temperature field and thermal stress field, the melting damage threshold intensity formula and the stress damage threshold intensity formula were obtained. Besides, the distribution of temperature field and thermal stress field in optical films were simulated by Matlab software. Simulation analysis showed that: If it was over the material melting temperature, the melting destruction occurred. And it started from the center. The center temperature rose faster than the edge. The compressive strength of the optical glass was far greater than the tensile strength. The material injury depended on the central control stress. The results indicated that temperature rose not only with the absorption of the material, but also with convective heat transfer coefficient. In the initial, thermal deformation of glass increased rapidly and it increased slowly later. At the same time, the heat distortion of the region nearer the beam was more obvious. The greater the laser power, the greater the variable-shaped.