The combination of volumetric heating of the laser material by the absorbed pump radiation and surface cooling required for heat extraction leads to a no uniform temperature distribution in the rod. With the coactions of pump field and coolant, the temperature gradient is formed within laser working medium, and then the thermal effects including thermal lens, thermal stress birefringence, etc. They all seriously restrict the output characteristics of laser. The uniform temperature field distribution in laser working medium weakens the influences of thermal effects in laser. The thermal effect of Tm:YAG laser generated by laser-diode pumping the Tm:YAG crystal is analyzed. After considering the quasi three-level structure of the crystal and the distribution of transmission power in the cavity, a more actual temperature field in the crystal is obtained by revamping the heat conversion coefficient. The thermal effects mechanics were analyzed at first, and then the physical and mathematical thermal analysis models were established based on the theoretical knowledge of thermal effects in LD pumped Tm:YAG laser. The method can be applied to the laser thermal effect research of quasi three-level. The analysis and the result can be referred to the thermal effect research of the solid state laser end-pumped by the LD and the optimal design of resonant cavity.

Date Published: 18 November 2014
PDF: 6 pages
Proc. SPIE 9266, High-Power Lasers and Applications VII, 92660N (18 November 2014); doi: 10.1117/12.2065236

Published in SPIE Proceedings Vol. 9266:
High-Power Lasers and Applications VII
Ruxin Li; Upendra N. Singh; Robert F. Walter, Editor(s)