200 W Quasi-continuous-wave Green Laser with a Dual-resonator Combined Cavity
200 W双谐振腔组合单向输出准连续绿光激光器

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%.