光导型HgCdTe光电探测器对双波段组合激光辐照动态响应的数值模拟

Numerical Simulation of Dynamic Response of PC-Type HgCdTe Detector Irradiated by in-Band and Out-of-Band Laser Beams

采用数值方法,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,以及器件温升对载流子寿命、浓度、迁移率和光吸收系数等材料参数的影响,通过求解粒子数平衡方程和热传导方程的联立方程组,研究了PC型HgCdTe光电探测器在波段内和波段外双光束组合激光辐照下的动态响应过程。计算结果证实了探测器对波段内和波段外激光的电压响应方向相反;结果显示探测器对波段外激光的反向电压响应随波段外激光功率升高迅速增大,线性区间的波段内背景光辐照使波段外光响应迅速增大,随波段内激光使探测器趋于饱和,波段外光响应逐渐减小。

By means of numerical methods, solving equations of current continuity and energy transport, the dynamic response of PC-type HgCdTe detector irradiated by in-band and out-of-band laser beams is studied in which two absorption mechanisms, including intrinsic carriers inter-band transition and free carriers inner-band transition, and dependence of material parameters, lifetime, concentration, transport rate and photoabsorption coefficient of carriers, on detector temperature are considered. It is proved that voltage response of the detector to the irradiation of out-of-band laser is opposite to that of in-band laser. The inverse voltage response to out-of-band laser increases rapidly with laser power. The voltage response to the out-of-band laser increases in the linear region for background-light illumination and decreases while in-band laser power reaches to the saturation threshold.