激光损伤非制冷微测辐射热计的实验研究

Experimental Study on Laser-induced Damage to an Uncooled Microbolometer

在市场需求驱动下,非制冷红外测辐射热计阵列在多个领域正逐步应用,对其激光干扰的研究也被提上了日程。本文以多晶硅探测器为例,结合非制冷微测辐射热计阵列的构造和工作原理,分析了激光辐照作用下的温度响应;通过10.6mm连续激光的辐照实验,得到了像元阵列进入不同损伤状态对应的激光功率范围,分析了激光损伤的热效应机制,指出干扰面积大于光斑面积是由于热量的“倒灌”;将战场上激光传输的影响简单等效为斩波调制,研究了调制频率和占空比对激光干扰效果的影响。经分析得出,在调制频率100~500 Hz、占空比0.1~0.5的范围内,连续激光对非制冷微测辐射热计在传输等效调制频率较低、占空比较大的条件下能得到更好的干扰效果。

Driven by market demand,uncooled infrared bolometer arrays are gradually becoming popular in several fields,and their laser interference has become a major research topic.In this study,based on the structure and working principles of an uncooled microbolometer array,temperature response under laser irradiation is analyzed.An experiment of 10.6mm continuous laser irradiation of an uncooled polysilicon detector shows that the pixel array enters different damage states.The laser power range and thermal effect mechanism of laser damage are also analyzed.Previous studies have shown that the interference area is larger than the spot area as a result of“heat inversion”and that the influence of laser transmission on the battlefield is equivalent to chopping modulation.T he effects of modulation frequency and duty cycle are also studied.Analytical results show that a continuous laser can achieve a better interference effect on an uncooled microbolometer with a low transmission modulation frequency and large duty ratio.