LD Pumped Microchip Laser

LD pumped microchip laser have wide applications in laser ranging, laser weapon, laser radar, laser medical, fine material processing, and environmental monitoring for its extremly compact cavity, long operating life, all solid-state, and easy to mass production. Microchip laser become a new trend in the development of solid state lasers. To get short pulse width, high repetition rate and stable laser pulses for the seed sources of the fiber laser, this thesis studied many contents, include theory analysis, numerical analysis and experiment study. The main contents can be summarized as follows:1. We analyzed the rate equation of the passively Q-switched microchip laser with SESAM. From the Q-switched theory analysis, we derived the expression of the laser pulse width, laser peak power and laser pulse energy. We build the numerical analysis model of the passively Q-switched microchip laser, obtained the influence of the main parameters of SESAM (modulation depth, relaxation time, saturable fluence, non-saturable loss) to the laser output.2. We studied the thermal effect of the microchip laser from two aspects: contious microchip laser and passively Q-switched microchip laser. From the numerical computation, we concluded that for microchip laser cooling the back surface of the crystal is better than cooling the surrounding of the crystal.3. In the Nd:YVO4 microchip laser experiment, we measured the contious microchip laser output with different output couplers, different cavity length, different doping density and different crystal thickness. We chose two kinds of SESAM for the study of the passively Q-switched microchip laser, the laser pulse width, average output power, repetition rate have been obtained. By contrasting the experimental results and the numerical model, we found that the results were consistent, so, this numerical model can provide a theoretical basis for future experimental designs of the microchip lasers.4. We analyzed the properties of the Nd:Yo.8Luo.2V04 crystal, sudied the cintious wave laser output.The maximum CW output power obtained was 737mW with the 9% output coupler, the optical conversion efficiency was 31.8%.5. A passively Q-switched Nd:Y0.8Lu0.2V04microchip laser with SESAM as the saturable absorber was demonstrated. In the Q-switching experiments, we obtained the maximum laser output power of 191mW at 580.2kHz repetition rate for laserl, leading to 8.23% optical conversion efficiency, and the pulse duration was 2.192ns, it is currently the shortest Q-switching pulse obtained from Nd:Yo.8Luo.2V04 microchip lasers. For laser2, we obtained the maximum laser output of 285mW at 1054kHz repetition rate, the optical conversion efficiency was 12.3%, the pulse duration was 2.663ns.