Analysis of thermal effects in a pulsed laser diode end pumped single-ended composite Tm:YAG laser

By studying the theory of heat conduction, we established the transient heat conduction equation for a pulsed laser diode (LD) end pumped thulium doped laser. Combined with the actual working environment of a pulsed LD end pumped single-ended composite Tm:YAG rod, the expressions of transient temperature distribution and the time-varying thermal focal length were obtained by the integral transform method and the method of separation of variables. Under 240 mJ pump energy and repetition rates of 80, 90, and 100 Hz, thermal effects in the pulsed LD end pumped single-ended composite Tm:YAG rod were simulated, and the thermal lens focal length of the single-ended composite Tm:YAG rod was measured in experiments. The theoretical analysis was verified by the comparison between the theoretical results and the experimental results. (paper)