Hg_0.826Cd_0.174Te crystal damaged by high repetition frequency CO₂ laser

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 10s, damage threshold of the crystal does not depend on the irradiation time, and the value is 1.4214103W/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.