皮秒光纤-固体混合放大紫外激光器

Ultra-violet picosecond fiber-solid hybrid amplification laser

脉冲宽度为皮秒级的紫外激光,拥有极窄的脉冲宽度,可在短时间内破坏物质的分子键,缩短了与物质相互作用的时间,同时具有较强的时间分辨率。为了获得皮秒级脉冲宽度的短波紫外激光,本文设计了一种皮秒光纤-固体混合放大213 nm激光器。采用重复频率为5 MHz、脉冲宽度为52 ps、平均功率为2.5 W的1064 nm光纤激光器作为种子源,经过两级端面泵浦的Nd∶YVO4晶体组成的放大器对种子光进行放大,得到了平均功率为10.5 W的1064 nm基频光输出。再将混合放大后得到的基频光及其四倍频后获得的266 nm激光在BBO晶体内进行和频,最终输出213 nm紫外激光。混合放大后获得的基频光经过多级非线性转换,最终输出脉冲宽度为690 ps、平均功率为61 mW的213 nm紫外激光,非线性转换效率达到0.58%。

Ultraviolet lasers with picosecond pulse widths can quickly break the molecular bonds of materials,reducing interaction time.At the same time,they have high temporal resolution.In order to obtain an ultraviolet laser with a picosecond pulse width,a solid fiber,hybrid-amplified 213 nm laser was designed.First,a 1064 nm fiber laser with a repetition rate of 5 MHz,pulse width of 52 ps,and average power of 2.5 W was used as a seed source.After two stages of end pumped Nd∶YVO4 crystal amplification,a 1064 nm laser with an average power of 10.5 W was obtained.This 1064 nm laser and a 266 nm laser were then combined in a BBO crystal to produce a 213 nm UV laser.The final output is a 213 nm UV laser with a pulse width of 690 ps and an average power of 61 mW.The nonlinear conversion efficiency is 0.58%.