Finite element analysis of thermal effect of photovoltaic detector irradiated by laser

A 3-D physical model of temperature rise for a photovoltaic detector irradiated by Gaussian CW laser is established. The 3-D temperature distribution of the detector is calculated with finite element analysis method. The effects of the irradiation time, the thickness and heat conductivity of glue layer on the melting damage threshold and heat recovery time are discussed. The research results show that the melting damage may occur in the InSb photovoltaic detector when it is radiated continuously by intense laser, and the damage takes place first in the light spot center of the radiated surface. The higher the laser power is, the shorter time the damage takes, and the greater the heat conductivity is, the bigger the damage threshold corresponding to the thinnest glue layer will be. However, only when the detector is radiated by the high power laser, will the effect of the thickness and heat conductivity of the glue layer on the melting damage threshold become clear. The results obtained from the research match well with the experiments. It is pointed out that the glue with high heat conductivity should be selected and the thickness of the glue layer should be made as thin as possible to improve the performance of the photovoltaic detector.