Numerical Thermal Model of Diode Double-End-Pumped Solid State Lasers

Abstract

In this work, a numerical analysis based on finite element method (FEM) has been used to predict both the temperature distribution and focal length in CW Nd:YAG laser rod. The double end-pumped utilizing two different pumping profiles, namely, Gaussian and super- Gaussian beam profiles are adopted in this simulation. In addition, four different super- Gaussian beam profiles (N = 4, 6, 10, 30) have been studied and compared with the Gaussian (N = 2) pump profile. At Gaussian pumping power of 40 W (20 W for each face), maximum center temperature is observed for each face of the two end-pumped faces were found, and start to decrease in the super-Gaussian case as the exponent factor N increases. The thermal lensing effect strongly depends on different factors, namely, power of the pump source, and distribution profile of the pump through the laser medium geometry. Therefore, the double-end-pumped method may be considered as important to reduce temperature gradiant in the laser rod while choosing the type of pumping profiles.