中文摘要：

报道了一台输出功率达50W量级的采用808nm高功率激光二极管双端抽运的Nd：YVO4复合晶体基模固体激光振荡器。双端抽运结构和复合晶体的采用有效地降低了激光晶体中的热效应，可在晶体中获得更加均匀的热分布和增益分布。使用非对称平平腔动态稳定腔结构，使激光器的两个稳定区分离，并使其运行在稳定区I中，这样不仅可以进行高功率抽运，而且可以获得很低的失调灵敏度。对谐振腔腔长进行优化后，在抽运功率约104W时获得了最高51．2W的基模连续激光输出，基模光光转换效率达49．2％；通过在腔内插入声光调Q器件，获得了重复频率在50～600kHz之间连续可调的脉冲激光输出。重复频率在100～600kHz之间时，平均输出功率可基本稳定在49W，脉冲宽度从18．2ns增加到85ns；重复频率50kHz时，平均输出功率43．2W，脉冲宽度13．5ns，峰值功率为64kW。

英文摘要：

A 50 W class, high power 808 nm laser diodes double-end-pumped Nd. YVO4 composite crystal laser oscillator is reported. The adoption of double-end-pumping configuration and composite crystal can effectively alleviate thermal effect and achieve more uniform thermal and gain distributions in the laser crystal. Asymmetrical plane-plane dynamically stable resonator is employed, which can make the two stable zones separated. Making the laser operated in stable zone I, we can pump the laser crystal with high pump power and get very small misalignment sensitivity, which are favorable for high power output and resonator＇s mechanical stability. After optimizing the length of the two cavity arms, we obtain 51.2 W continuous-wave （CW） TEM00 mode laser output with about 104 W pump power, corresponding to an optical-to-optical efficiency of 49. 2%. With an acousto-optic （AO） Q-switch inserted into the resonator, pulsed laser can be obtained within the pulse repetition rate range of 50 - 600 kHz. Within the pulse repetition rate range of 100-600 kHz, the average output power is stable at 49 W and the pulse width changes from 18.2 ns to 85 ns. At a pulse repetition rate of 50 kHz, the average output power reduces to 43.2 W with pulse width of 13.5 ns and peak power of 64 kW.