PC型HgCdTe光电探测器在双波段组合激光辐照下的温升计算

Temperature changes in PC-type HgCdTe detector irradiated by in-band and out-of-band laser beams

把传统漂移扩散模型和热传导方程相结合,模型中波段内正常探测信号激光作为背景光,波段外激光作为干扰和毁伤用激光,考虑波段内激光的本征载流子带间跃迁吸收和波段外激光的自由载流子带内跃迁吸收的光吸收机制,以及器件温升与载流子寿命、浓度、迁移率和光吸收系数等材料参数之间的相互影响,数值计算了PC型HgCdTe光电探测器在双波段组合激光辐照下的温度响应过程,得到了不同功率密度的波段内和波段外激光组合辐照对探测器温升的影响,以及使探测器达到破坏阈值温度的波段外激光辐照时间。结果证实了波段内背景激光辐照是增大波段外激光吸收系数,从而降低波段外激光破坏阈值的有效途径;较低功率密度的波段内背景激光辐照可极大缩短波段外激光的破坏时间,波段外激光毁伤存在最高效率点。

A model which combines drift-diffusion equation and heat transmission equation is established. Considering two laser absorption mechanics, including intrinsic carriers inter-band transition and free carriers inner-band transition, and the interaction of detector temperature and material properties, such as lifetime concentration mobility of carriers and absorption coefficient, the temperature responses in PC-type HgCdTe detector irradiated by in-band and out-of-band laser beams are calculated. The relationship between laser power density, irradiating time and the temperature rise is discussed. Results show that in-band laser irradiation can increase out-of-band laser absorption, and is an effective way to reduce damage thresholds.