Simulation of absorbed power and temperature distribution in LD side-pumped laser

Ray-tracing algorithm and finite difference method were used to simulate the absorbed power and temperature distributions in crystal rod for different side-pumping configurations. Simulation results show that there have importance influences on the absorbed power and the temperature distributions at different pumping configurations and parameters. With the increase of pumping sides, both the absorbed power and the temperature distributions with in the crystal are gradually becoming a symmetric distribution about the crystal axis. Some methods to increase the uniformity of the absorbed power distributions are introduced. The relation between the temperature in the cross-section of the laser rod and the heat transfer coefficient is investigated. The former nonlinearly decreases with the increase of the latter, and the coefficient has an optimal value. Therefore, an appropriate flow rate should be chosen according to different pumping power.