飞秒激光直写Nd:YVO4晶体包层波导激光

Cladding waveguide lasers in femtosecond laser written Nd:YVO_4 crystals waveguides

采用飞秒激光(500 kHz重复频率)直写技术,在Nd:YVO4晶体中制备了埋藏晶体表面以下的包层光波导.具体研究了脉冲能量、深度、扫描速度和飞秒激光偏振等写入条件对光波导性能的影响.1.06μm波长的激光在光波导中传播时,光波导的插入损耗低至2.4 dB.利用808 nm波长的激光泵浦,在室温下实现了1064 nm波长发射的连续波导激光器.对不同直径的光波导,均实现了多模光波导和波导激光.直径为60μm的波导产生的最大输出功率为143 mW,斜率效率为21.3%.利用微拉曼光谱对光波导进行了表征,激光直写轨迹处晶格被破坏,伴随折射率降低.

We have reported the formation of buried cladding waveguides in Nd:YVO_4 crystals by femtosecond laser writing at a repetition rate of 500 kHz.The effects of the writing conditions such as pulse energy,depth,scanning speed and femtosecond laser polarization on the optical waveguide performance were specifically studied.The insertion loss of the waveguide at 1.06μm was as low as 2.4 dB.A continuous waveguide laser emitted at 1064 nm was achieved at room temperature by using a laser pump at 808 nm.Multimode guiding and lasing were realized in the waveguides with different diameters.The waveguide with a diameter of 60μm generates a maximum output power of 143 mW and a slope efficiency of 21.3%.The optical waveguide is also characterized by using micro Raman spectroscopy,showing that the lattice structure of the laser-induced region is destroyed resulting in refractive index decreases.