ZnS与SiO_2材料的短脉冲激光热损伤特性比较

对SiO2和ZnS这两种常用的红外光学材料在红外短脉冲激光辐照下的热损伤特性进行了研究,分析了相同激光辐照条件下两种材料的热效应,另外也针对同种材料不同辐照条件下的热效应进行比较。分析结果表明:红外激光作用下,SiO2材料的表面温升快于ZnS材料,而在材料内部,则后者快于前者。脉冲辐照结束时SiO2材料的表面峰值温度高于ZnS材料,但ZnS材料产生温升的深度大于SiO2材料。由于能量更为集中,材料在皮秒激光作用下温升高于纳秒激光作用下的温升。若材料的峰值温度达到熔点,则激光的单脉冲能量随脉冲宽度的减小呈非线性减小趋势,且变化率越来越大。

Comparative analysis on thermal damage characteristics of ZnS and SiO2 induced by short pulse laser

The thermal damages of the frequently-used infrared optical materials ZnS and SiO2 induced by infrared short pulse laser were studied. The thermal effect of ZnS and SiO2 irradiated by the same laser were analyzed. The thermal effects of ZnS and SiO2 irradiated by different laser were respectively analyzed. The following conclusions were drawn. The temperature on the surface of SiO2 rose faster than that of ZnS irradiated by the infrared laser. The temperature under the surface of SiO2 rose slower than that of ZnS. Peak temperature of SiO2 was higher than the latter. The depth of the region where its temperature was above normal in the SiO2 was shallower than that in the ZnS. Temperature of materials in the case of picosecond pulse laser rose faster and higher than that in the case of nanosecond pulse laser for the energy of picosecond pulse laser was more concentrated. As the pulse width diminished, the single pulse energy of laser nonlinear decreased and the rate of change grew, which made the peak temperature achieve melting point.