Diode-pumped solid state laser system based on cryogenic Yb:YAG active-mirror scheme are presented with recent energy output. With improved optical design, 6.05J/1Hz pulse energy is achieved and a conceptual design with 30J output energy is theoretical simulated. The doubling efficiency of YCa<sup>4</sup>O (BO<sup>3</sup>)(YCOB) crystal is also discussed in this paper.
Thermal effect is a serious problem in solid-state lasers. Because of superior thermal property which owed to high aspect ratio of laser crystal, solid-state lasers with thin slab configuration can be scaling to high output power with different laser crystal material and pump structure. In this paper, we present side-pumped passive Q-switched and acousto-optic Q-switched Nd: YAG lasers and end-pumped Tm: YAP lasers. We got a maximum 70W output power of passive Q-switched Nd: YAG laser with 220W pump power, which the pulse duration is around 10ns and the pulse repetition rate is higher than 10kHz. And 73W output power is got while pump power is 200W in acousto-optic Q-switched Nd: YAG lasers. Especially, we also applied the thin slab configuration to end pumped Tm: YAP laser and got a maximum 9.6W output power which the doping concentrations is 4% and cut by c-axis.