高效率连续波运转的激光二极管端面抽运914 nm Nd:YVO4激光器

利用激光二极管(LD)抽运Nd∶YVO4晶体产生914 nm谱线振荡,再通过腔内倍频技术获得457 nm激光输出,是获得大功率蓝光激光器的一条重要的技术路线,因而实现高效率运转的914 nm激光输出则是方案的关键。报道了激光二极管端面抽运Nd∶YVO4晶体、连续波运转的大功率914 nm准三能级激光器,方案中采用掺杂原子数分数为0.1%的低掺杂Nd∶YVO4晶体,有效地降低了热效应的影响,并通过准三能级理论模型的模拟计算选择了最佳晶体长度;通过对腔镜介质膜参数的适当控制,有效地抑制了波长为1064 nm和1342 nm的高增益谱线。实验中,914 nm激光器的阈值抽运功率仅为8.5 W,在31 W的抽运功率下914 nm激光输出功率高达7.2 W,激光器的斜率效率为32%,光-光转换效率为23.2%。

High Efficiency Continuous-Wave Laser-Diode-End-Pumped Vanadate Laser Operating on 914 nm

Means of intra-cavity frequency doubling 914 nm transition of Nd:YVO4 pumped by laser diode (LD) is an important technical scheme to get high power blue laser output, thus achieving high efficiency 914 nm laser is the key point. A high power continuous-wave (CW) end-pumped Nd:YVO4 laser operating at 914 nm by utilizing a quasi-three-level transition was demonstrated. A 0.1% Nd-doped bulk Nd:YVO4 was applied to reduce the thermal effect in the laser crystal. In order to avoid re-absorption losses further, a suitable length of the crystal was chosen based on a careful calculation. Two wavelengths of 1064 nm and 1342 nm with high gain were restrained effectively by suitable control of the parameters of the medium film on cavity mirrors. Finally, the laser was operated at a very low threshold at the pumping power of 8.5 W, and a 914 nm laser with power of 7.2 W was gotten at the pumping power of 31 W. The slope efficiency of the laser was 32%, and the optical-to-optical efficiency was 23.2%.