Nd:GYSGG/YVO4双波长人眼安全波段内腔拉曼激光器

以Nd:GYSGG晶体为激光增益介质,a切割YVO4晶体为拉曼增益介质,利用Nd:GYSGG晶体的双波长激光运转特性实现声光调Q 1.5 m人眼安全波段双波长内腔拉曼激光器。为克服Nd:GYSGG晶体严重的热透镜效应对激光器功率的限制,实验确定其同带泵浦吸收峰位置及吸收系数,采用同带泵浦方式减轻热效应。吸收882.9 nm泵浦光功率17.1 W时,在20 kHz的脉冲重复频率下获得1.44 W的1.5 m双波长输出,转换效率8.4%,光束质量因子M2=2.4;棱镜分光测得其中1 497 nm和1 516 nm功率分别为0.55 W和0.89 W,二者脉冲宽度相近,均为15.3 ns左右。与808 nm传统泵浦相比,同带泵浦方式下激光器的输出功率及光束质量均得到明显提升。

Dual-wavelength eye-safe laser based on Nd:GYSGG/YVO4 intracavity stimulated Raman conversion

A compact AO Q-switched dual-wavelength laser operated in 1.5 m eye-safe region was demonstrated via stimulated Raman scatting of a-cut YVO4 crystal within an end-pumped dual-wavelength Nd:GYSGG laser cavity. The in-band pumping absorption peak and coefficient were measured to conduct efficient pumping, thus overcoming the drawback of short thermal focal length of Nd:GYSGG crystal and scaling up the eye-safe output. 1.44 W of simultaneous output at 1 497 and 1 516 nm was obtained under absorbed pump power of 17.1 W at the pulse repetition rate of 20 kHz, corresponding to a conversion efficiency of 8.4%. The 1 497 nm and 1 516 nm fractions are 0.55 and 0.89 W, respectively, measured after split by a prism. The beam quality factor M2 is 2.4 at the maximum output. Compared with 808-nm traditional pumping, both the laser output power and the beam quality are greatly improved.