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

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/cm²~71.9 mJ/cm², 61.0 mJ/cm²~207.8 mJ/cm² and 352.6 mJ/cm², 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/cm², which was close to the experimental results and proved the correctness of the analysis of CCD damage mechanism.