LD-side-pumping schemes for a solid-state laser offer the advantages of both high pump efficiency and high output power. However, thermally-induced lens has been known to severely affect the performance of high-powered solid-state lasers. To solve the problem, a systematic simulation model was developed by combining two procedures of ray tracing and finite element method (FEM) together to explore the thermal lens characteristics of a high-powered Nd:YAG laser. The relationship between the spatial heat density distribution and thermally-induced refractive index distribution was investigated by taking an inhomogeneous pentagonal pumping into account. The influence of a pentagonal pumping on the characteristics of the thermal lens focal length of a laser rod was studied afterwards. According to the results, if the volume average heat density of a laser rod is kept as a constant, the focal lengths of a thermally-induced lens in the pentagonal pumped laser rods will be shorter than those of the homogeneously pumped laser rods with different rod diameters. It has also been demonstrated that the focal lengths of both pumping cases are not sensitive to the variation of the rod diameter. The study is thought to be helpful for the design of a high-powered solid-state laser.
In order to satisfy the requirements of laser irradiation and laser ranging over the long distance, and to realize the miniaturization, the modularization and the engineering application of 1J high-energy DPSSL circuit system, a laser driving circuit system is designed according to the laser work patterns of one oscillator stage and two amplification stages. The system includes many parts, such as the integrated power supply circuits, the corresponding LD drivers of three stages, the signal control circuits, the Q switched circuits, the receiving circuits and the temperature control circuits, etc. It possesses the characteristics of 28VDC input power source, working frequency 25Hz，driving laser output 1J, working stable and reliable, thermal management optimization and small size as well as light weight. The study promotes the comprehensive technical specifications of the platform load effectively and can also provide a valuable reference for the miniaturization of high energy DPSSL circuit system.
A 1J LD pumped Nd;YAG pulsed laser was designed. The laser uses an oscillation and two-staged amplification structure, and applies diode bar integrated array as side-pump. The TEC temperature control device combing liquid cooling system is organized to control the temperature of the laser system. This study also analyzed the theoretical threshold of working material, the effect of thermal lens and the basic principle of laser amplification. The results showed that the laser system can achieve 1J, 25Hz pulse laser output, and the laser pulse can be output at two width: 6-7ns and 10ns, respectively, and the original beam angle is 1.2mrad. The laser system is characterized by small size, light weight, as well as good stability, which make it being applied in varied fields such as photovoltaic radar platform and etc