416nm 纳秒脉冲激光对CCD损伤机理研究

Research on damage mechanism of 416 nm nanosecond pulsed laser to CCD

开展了416 nm纳秒脉冲激光对CCD的损伤实验,观察到了CCD从点损伤到线损伤,再到面损伤的过程,并计算出了点损伤、线损伤和面损伤所对应的损伤能量密度阈值分别为16.7 mJ/cm^(2)~71.9 mJ/cm^(2)、61.0 mJ/cm^(2)~207.8 mJ/cm^(2)和352.6 mJ/cm^(2);通过对不同损伤状态CCD的损伤点表面显微图像的分析,以及不同损伤状态对应的CCD各电极之间电阻值的测量,得出不同损伤状态主要由二氧化硅绝缘层材料相变引起电阻值改变所产生;COMSOL软件仿真显示CCD各层最先产生熔融的是二氧化硅绝缘层,能量密度为420 mJ/cm^(2),与实验结果相接近。实验结果证明了CCD损伤机理分析方法的正确性。

The damage experiment of 416 nm nanosecond pulsed laser to charge-coupled device(CCD)was carried out.The process from point damage to line damage and then to surface damage was observed.The damage energy density thresholds corresponding to point damage,line damage and surface damage were calculated to be 16.7 mJ/cm^(2)~71.9 mJ/cm^(2),61.0 mJ/cm^(2)~207.8 mJ/cm^(2) and 352.6 mJ/cm^(2),respectively.Through analyzing the microscopic images of the damage point surface of CCD in different damage states and measuring the resistance values between CCD electrodes corresponding to different damage states,it was concluded that the different damage states were mainly caused by the different changes of resistance values caused by the phase change of silicon dioxide insulating layer material.Through simulation of COMSOL software,it was concluded that the silicon dioxide insulating layer was the first layer to melt in each layer of CCD,and the energy density was 420 mJ/cm^(2),which was close to the experimental results and proved the correctness of the analysis of CCD damage mechanism.