Influence of materials' property of laser crystal on thermal effects in high-power DPL

摘要

The physical property parameters of laser crystal in solid state lasers vary strongly with temperature, which will intensely affect the thermal effects of high power LD pumping solid state laser (DPL). In this study, by correcting the intensity distribution of the laser beam emitted from the pumping source of laser diodes, a heat transmission model for the laser crystal of a side-pumping geometry with a triangle uniform distribution was established. The temperature and stress distribution are calculated and compared using finite element method under two different conditions, which thermal conductivity, heat capacity and coefficient of thermal expansion of the laser crystal media vary with the temperature, and these physical property parameters are constant. The results show that temperature at the center of laser crystal media will further increase, and there will produce an additional stress except for thermal stress due to the temperature gradient at the radial direction in the laser crystal, which result in more serious thermal effects. This study provides a more visual and accurate reference model for the design and optimization of high power laser diode side pumped solid state lasers.