摘要
开展了HgCdTe晶体的多脉冲热损伤问题的实验研究。采用形貌学方法对脉宽为300 ns重复频率可调的CO2激光器对Hg0.826Cd0.174Te晶体的损伤阈值进行了实验测量,并建立了高重频脉冲CO2激光辐照Hg0.826Cd0.174Te晶体的三维热传导理论模型,分析了激光重复频率和辐照时间对晶体损伤特性的影响。研究表明:300 ns的CO2激光辐照时间大于10 s时,Hg0.826Cd0.174Te晶体的损伤阈值不随辐照时间的增加而改变,其损伤阈值为1.421 4×103W/cm2;激光重频对晶体的损伤阈值的影响较小,损伤阈值主要取决于辐照激光的平均功率密度。SEM损伤结果显示:晶体损伤为热熔损伤,表面未发现由热应力造成的裂缝。理论模型获得的损伤数据和温升规律支持实验结果。该研究可为高重频CO2激光应用、激光防护等提供参考。
In order to obtain HgCdTe crystal thermal damage threshold irradiated by high repetition frequency laser, firstly, irradiation effect experiment was conducted on the Hg0.826Cd0.174Te crystal by high repetition frequency CO2 laser with a pulse width of 300 ns. Then the theoretical model of Hg0.826Cd0.174Tecrystal irradiated by high repetition frequency CO2 laser was developed to calculate thermal damage process of Hg0.826Cd0.174Te crystal. Finally,the impact of irradiation time and repetition frequency on damage threshold was analyzed. The research results show that when the irradiation time is longer than 10 s, damage threshold of the crystal does not depend on the irradiation time, and the value is 1.421 4í103 W/cm2. Damage threshold mainly depends on average power density,and doesn’t depend on repetition frequency. Damage results of SEM show the crystal damage is thermal damage, and the obvious crack is not found on the surface. The model prediction agrees well with the experiment data, and the conclusions have a reference value for laser application and laser protection on high repetition frequency CO2 laser.
出处
《红外与激光工程》
EI
CSCD
北大核心
2013年第10期2663-2668,共6页
Infrared and Laser Engineering
基金
国家重点实验室自主基础研究课题(SKLLIM1004-01)
关键词
损伤阈值
高重频
HGCDTE晶体
damage threshold
high repetition frequency
HgCdTe crystal
