Research On Passively Q-switched Microchip Laser

Recently years, the laser has short pulse width, high peak power, and high repetition rate has attracted more and more attention. This laser can be used in medicine, machining, and so on. While passively Q-switched microchip laser is the most important method to achieve this laser. The diode-pumped Nd:YAG/Cr⁴⁺:YAG passively Q-switched lasers at 1064nm and 532nm are studied theoretically and experimentally in this paper. We also studied the laser of OPO at 1534nm. The main content can be generalized as follows:1. The diode-pumped Nd:YAG/Cr⁴⁺:YAG passively Q-switched microchip laser at 1064nm was experimentally studied in this paper. By using composite crystal Nd:YAG/Cr⁴⁺:YAG and an optimal cavity. At the incident pump power of 11.8 W, the shortest pulse width of 2.0 ns was obtained, corresponding to average output power of 1.15W and repetition rate of 17.1 kHz. The single-pulse energy and peak power were estimated to be 67.3μJ and 32.8kW, respectively. In another experiment, the cavity mirrors were deposited directly onto the crystal. The shortest pulse width 1.5ns was obtained. A single diode-pumped passively Q-switched composite Nd:YAG/Cr⁴⁺:YAG laser ,which cavity mirrors were deposited directly onto the crystal, was demonstrated in this paper also. At the incident power of 2.75W, the maximum average output power of 365mW and the shortest pulse width of 1.7ns were obtained, corresponding the repetition rate of 14.6 kHz. The single-pulse energy and the peak power were estimated to be 25μJ and 14kW, respectively. The corresponding optical-optical conversion efficiency was 13.3%.2. The diode-pumped Nd:YAG/Cr⁴⁺:YAG passively Q-switched microchip laser at 532nm was experimentally studied in this paper. A compact diode-end-pumped passively Q-switched intra-cavity frequency doubled diffusion bonded Nd:YAG/Cr⁴⁺:YAG composite crystal laser was demonstrated. The minimum pulses width was about 3.4ns with repetition rate of 27.5 kHz and output power of 0.5W under the pump power of 14W, corresponding single-pulse energy of 18μJand peak power of 5 .3kW. By deposited the cavity mirror directly onto the composite Nd:YAG/Cr⁴⁺:YAG crystal, the passively Q-switched out-cavity frequency doubled laser was demonstrated. The minimum pulses width was about 1.3ns.3. By using a typeⅡnon-critical phase-matched KTA crystal, the KTA-IOPO was realized in a diode end-pumped composite Nd:YAG/Cr⁴⁺:YAG laser. The single average output power of 480mW was achieved under the incident power of 11.8 W. The corresponding pulse width was 1.2 ns.