TEA-CO2激光辐照HgCdTe图像传感器的实验研究

利用TEA-CO₂激光对碲铬汞(HgCdTe)图像传感器的干扰和损伤现象进行了实验研究，分析了干扰和损伤机理。探测器上激光能量密度小于255 mJ/cm2时,饱和像素仅出现在光斑区域，激光能量密度为425.8 mJ/cm2时，像素被损伤，观察到了弥散斑和暗环等现象。建立了探测器的激光辐照模型，计算了探测器的温升，讨论了温升与载流子浓度、迁移率的关系。分析认为，弥散斑的出现是探测器升温产生的热激发载流子浓度扩散所致，暗环的出现是迁移率与载流子浓度扩散共同作用的结果，像素的损伤则是因为温升导致汞的析出。

Experimental Study of HgCdTe Imaging Sensor Irradiated by TEA-CO2 Laser

The disturbance and damages of TEA-CO2 laser to HgCdTe imaging sensor are researched experimentally and theoretically. The saturation of pixels of the HgCdTe detector just appears inside the facula when the energy density on it is less than 255 mJ/cm2. Pixels are damaged when the energy density is 425.8 mJ/cm2, and a dispersed spot and a dark ring are observed. By the simulation of the HgCdTe detector under CO2 laser irradiation, the temperature distribution of the detector is calculated. The relationship among temperature-rise, carrier density and mobility of the detector is discussed. The dispersed spot occurs because of free carriers excited by heat diffuse under carrier density grades. The dark ring appears because of both of the mobility changing and carrier density diffusing. Hg atoms separate out from the detector due to their high temperatures, resulting in the pixels damage.