耦合光学系统是端面抽运固体激光器中不可缺少的部分, 其成像质量的优劣直接影响到激光器转换效率的高低。以激光二极管(LD)端面抽运Nd∶YVO4/LBO 457 nm蓝光激光器为例, 分别采用两种不同结构的准直聚焦透镜组合作为耦合光学系统, 分析其对抽运光的成像情况以及对端面抽运固体激光器光束质量和输出功率的影响, 在激光器的抽运功率和谐振腔的参数完全相同的情况下, 改进的四片式耦合光学系统使激光器输出的光束质量得到了明显改善, 同时极大地提高了倍频输出功率, 在30 W的抽运功率下, 得到了4.3 W的连续457 nm蓝光激光输出, 光-光转换效率达到13.7%。

Coupling systems are the key elements in end-pumped solid-state lasers, the aberrations of which greatly affect the efficiency of the lasers. A laser diode (LD) end-pumped Nd∶YVO4/LBO blue laser at 457 nm was taken as an example, the effects of aberrations of different coupling systems on the beam quality and the output power of the end-pumped solid-state laser were analyzed. At the same incident pump power and the same cavity parameter, the beam quality and the output power were greatly improved using the improved coupling system, at incident pump power of 30 W, continuous-wave output power of 4.3 W at 457 nm was achieved, the optical-to-optical conversion efficiency was 13.7%.