Reschearch On LD High Repetition Frequency Tm:YAP Q-Switched Laser

As Tm solid-state laser whose output wavelength is near 2 microns and that is in the atmospheric window, the applications in laser detection, laser ranging, photoelectric detection and environmental are becoming more and more significant and extensive. Especially, Tm:YAP lasers is the ideal light source for 3 to 5 microns, 8 to 12 microns optical parametric oscillation(OPO). LD pumped high repetition frequency Tm:YAP Q-switched lasers was studied and explored from theory and experiment.In theoretical aspect, through the analysis of the laser energy level transition process and the continuous operation cases rate equation model, the rate equation model of the Tm:YAP Q-switched laser was established firstly. And then the relations about output energy, pulse width and repetition frequency of Tm:YAP Q-switched laser were discussed. Due to the Tm: YAP crystal thermal effect, we analyzed thermal effect of laser through Comsol software and designed the cavity of high repetition frequency Tm: YAP Q-switched lasers.In experimental aspect, first of all, we studied the output characteristic LD end pumped Tm:YAP continuous laser. The maximum output power was 6.87 W with the slope efficiency of 39.4% when the input power was 21.15 W. For the research of LD single-ended pumped high repetition frequency Tm:YAP Q-switched laser, we discussed the impact of the cavity length, output mirror curvature and frequency on the laser output characteristics. Both indigenous and imported Tm:YAP crystal were used in the experiment, and the output characteristics of the two kinds of crystals were in comparison. At the frequency of 1kHz, the laser central wavelength of the indigenous crystal was 1988.4 nm, with the largest single pulse energy of 3.12 mJ and laser output pulse width of 65.6 ns. In the experiment, we measured laser output parameter value at the frequency of 1 kHz, 2 kHz, 5kHz and 10 kHz, studied the effect on Tm:YAP Q-switched laser with the increasing of frequency, and compared with the theoretical results. The maximum output power was 4.3W at 10 kHz.