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Numerical research on thermal effect of photodiode damaged by nanosecond pulsed laser

In order to better study the damage effect of nanosecond pulsed laser on PIN photodiodes, a two-dimensional axisymmetric model and heat source model of nanosecond irradiation photodiodes were established according to the theory of heat conduction, and the factors of thermal physical parameters changing with temperature were considered. The finite element COMSOL Multiphysics software was used to simulate the temperature field distribution of PIN photodiodes irradiated by nanosecond pulse lasers. The research results show that the temperature change trend of the target surface under different energy densities is consistent, and there is a phenomenon of energy ac-cumulation. From the center of the irradiation to the edge of the target, the temperature gradually weakens and dis-tributes in a gradient. and the temperature rise rate of the target is directly proportional to the increase in energy density. It is found that the melting damage of the photodiode is reached. The range of energy density is, 144.01mJ/cm2 ~ 175.58 mJ/cm2 , The research results provide a theoretical basis for the research field of laser damage to materials.