Comparison of Tm:YLF and Tm:YAP in thermal analysis and laser performance

Abstract

The a-cut Tm:YLF and c-cut Tm:YAP laser performance for 1.94 μm in dual-end pump configuration are compared in this paper. Higher slope efficiency and better beam quality are obtained for Tm:YLF lasers than Tm:YAP lasers in our present experiment. Theoretically, the temperature distribution and thermal focal length of Tm:YLF and Tm:YAP with a dual-end pump structure are analyzed. The thermal focal length, which is deduced from the backward calculation with the measured M2 factor, is much longer for Tm:YLF than Tm:YAP, indicating a weaker thermal lens effect for the Tm:YLF laser, which is in agreement with the theoretical value deduced from the temperature distribution in the rod. In addition, a rate equation model is used to simulate the laser performance and is found to have reasonable agreement with the experimental acquired data.