高效率LD端面抽运准连续355 nm激光器

报道了一台激光二极管（LD）端面抽运Nd：YVO₄晶体腔内倍频和腔外和频相结合的声光调Q准连续355 nm 紫外激光器。采用LD端面抽运双侧翼键合YVO₄基质的Nd：YVO₄晶体，在腔内置入Ⅰ类相位匹配的LiB₃O₅（LBO）晶体进行倍频实现1 064 nm和532 nm双波长准连续激光输出，通过消色差透镜将双波长激光聚焦耦合到Ⅱ类相位匹配的LBO 晶体中进行和频，并采用双向和频光路，获得了高效率、高光束质量、高重复频率的准连续355 nm 紫外激光输出。在抽运功率为28.6 W、重复频率为20 kHz时，355 nm激光最大输出功率4.2 W，脉宽为20.6 ns，光-光转换效率为14.7%，激光器光束质量因子M_x²和M_y²分别为1.29和1.23。

High Efficient LD End-pumped QCW 355 nm Laser

A laser diode (LD) end pumped acousto-optic Q-switched Nd:YVO₄ solid state 355 nm ultraviolet laser is reported by using intra-cavity double frequency and extra-cavity sum frequency technique. Nd:YVO₄ crystal bonded by YVO₄ in its both sides is end-pumped by LD, and typeⅠphase matched LiB₃O₅ (LBO) as the second harmonic generation crystal is placed in the cavity. 1 064 nm and 532 nm dual wavelength output from the cavity are coupled into the typeⅡ phase matched LBO crystal through an achromatic lens. High efficiency, good beam quality and high repetition rate 355 nm ultraviolet laser is obtained by sum frequency mixing back and forth. The 4.2 W 355 nm laser is obtained at the pump power of 28.6 W and the repetition frequency of 20 kHz, with the pulse width as short as 20.6 ns. The optical to optical conversion efficiency is about 14.7%. The beam quality factor M_x² and M_y² of 355 nm ultraviolet laser are 1.29 and 1.23, respectively.