Numerical Simulation And Experimental Study Of Dazzling Effects On Area Array CCD Induced By Laser

When the charge coupled device(CCD)is irradiated by intense laser,the image quality may decrease and reversible dazzling effects or irreversible destruction occur.There are research hot-spots in the field of laser-material interaction that analysis of laser interference mechanism and measuring of saturation threshold on CCD.Based on the work processes of CCD and charge-coupled principle,the soft damage characteristics of laser-irradiated CCD are studied,and the physical model is established.In the vertical direction of the channel,a one-dimensional model of the buried channel CCD storage signal charge cell is given.In the horizontal direction of the channel,a transfer model of the carrier is established based on the carrier continuity equation,the current density equation and the Poisson equation.The physical model embodies the limitation with the amount of signal charge that the CCD can store and handle.Numerical simulation was performed using the finite element analysis software.A two-dimensional numerical model of the N-buried channel CCD is established.The model can simulate the instantaneous state of parameters such as potential well voltage,charge amount,and electron concentration,thereby calculating the potential well capacity and deriving the saturation threshold.Combined with the setting of the CCD's working clock,it is possible to simulate the characteristics of the device when crosstalk occurs.The experimental system of low power laser irradiation CCD was designed and built,and the laser dazzling effects were completed.The laser conditions include CW laser and pulsed laser of different repetition frequency at 1064 nm.The laser saturation threshold of the Sony-ICX405AL interline transfer area array CCD is 1.46 mW/cm~2.The first and second crosstalk phenomena based on the overflow of the collector well and the vertical channel are observed in the experiment,then found the third crosstalk of the area array CCD based on the overflow of the horizontal channel.The formation mechanism of the three types of crosstalk is summarized.The special interference phenomena caused by the dynamic electronic shutter technology of CCD,such as background disappearance,horizontal fringes,and main light spot oscillation under low-frequency pulse irradiation,were found and analyzed.