200 W双谐振腔组合单向输出准连续绿光激光器

研究了最大平均输出功率达206 W的高功率准连续绿光激光器.利用ABCD定律及高斯光束在腔内的自再现条件,分析了激光晶体热透镜效应及热致双折射效应对谐振腔稳定性和输出光束质量的影响.实验中将两个型号相同的LD侧面泵浦激光模块分别置于一个平-凹V型谐振腔和一个平-凹直腔内,形成两束稳定运转的1 064 nm基频光,经过声光Q开关和倍频晶体后,产生两束倍频光,均到达平面折叠镜,最终由平面折叠镜单向重叠输出.当激光模块的泵浦电流为50 A,声光调Q的重复频率为22.4 kHz时,最大平均输出功率为206 W,最大单脉冲能量为9.2 mJ,脉冲宽度为201 ns,峰值功率为45.8 kW的532 nm绿光输出,倍频效率达到60.2%.激光器2 h工作的功率不稳定度优于2.5%.

200 W Quasi-continuous-wave Green Laser with a Dual-resonator Combined Cavity

206 W High-power quasi-continuous wave green laser was demonstrated.The thermal lens effect and the birefringence effect of laser crystals were analyzed,which affected the cavity stability and output quality using the ABCD law and the self-reproduce condition in cavity of Gauss beam.The two modules were placed in a plane-concave V-type resonator and a plane-concave straight cavity,and two stable operation beam of the 1 064 nm fundamental frequency laser were formed.Through acousto-optic Q-switched and frequency doubling crystal,two double-frequency laser beams arrived at the folded flat mirror,which were unidirectional output by the folded flat mirror at the end.As the pumped current was 50 A,the 532 nm green laser maximum average output power of 206 W at a repetition of 22.4 kHz was achieved with a pulse width of 201 ns and the largest single pulse energy of 9.2 mJ,corresponding to a peak power of 45.8 kW and a double frequency efficiency of 60.2%.When laser has been working for more than 2 hours,the instability of output power is less than 2.50%.