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

The alpha-cut Tm:YLF and c-cut Tm: YAP laser performance for 1.94 mu m 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 M(2) 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. (C) 2011 Optical Society of America