中文摘要：

采用中心波长为940nm的激光二极管泵浦,实现了Yb：YAG薄片的Cr4＋：YAG被动调Q激光输出.Yb：YAG薄片掺杂Yb3＋离子浓度为10%,厚度为500μm.理论上计算了Yb：YAG薄片在直接水冷方式与不同厚度SiC冷却方式下的温度分布.实验中采用厚度800μm的SiC冷却方式,获得了最高功率2.8 W的1 030nm连续激光输出,输出功率相比直接水冷方式提高了40%.通过Degnan理论优化了被动调Q晶体Cr4＋：YAG的初始透过率和输出耦合镜,采用初始透过率为93%的Cr4＋：YAG晶体和透过率为10%的输出耦合镜,在800μm SiC冷却方式下,获得了平均输出功率1.95 W、单脉冲能量1.2mJ、脉冲宽度74ns、重复频率1.6kHz的稳定调Q脉冲输出,斜效率为18.1%.光束质量因子M2x=1.622,M2y=1.616.

英文摘要：

Using 940 nm diode laser as pumping source,apassively Q-switched Yb：YAG thin disk laser by Cr4＋：YAG was realized.The Yb：YAG disk with 500μm thickness was employed,the Yb3＋atom fraction is 10%.The distribution of temperature in Yb：YAG disk with direct water cooling and SiC cooling with different thickness was theoretically simulated,respectively.The maximum output power of2.8 Wat 1 030 nm was obtained with 800μm SiC cooling,the output power has increased by 40%than that obtained with direct water cooling.The initial transmission of Cr4＋：YAG crystal and the output coupling rate were optimized by Degnan′s theory.With the initial transmission of Cr4＋：YAG crystal of93% and the output coupling rate of 10%,a stable pulse train of 1.95 Waveraged output power with a pulse energy of 1.2mJ and pulse width of 74 ns were obtained with 800μm SiC cooling.The repetition rate is 1.6kHz,the slope efficiency is 18.1%,and the beam quality M2x=1.622,M2y=1.616.