采用射频磁控溅射技术与热退火处理制备了纳米锗镶嵌二氧化硅(nc-Ge／SiO2)复合薄膜。对薄膜的光吸收谱进行分析,得到了纳米Ge晶粒的光学带隙。单光束Z-扫描的实验结果表明薄膜具有较强的可饱和吸收特性。将薄膜作为可饱和吸收体插入LD端面抽运的Nd:YVO4激光器内,分别实现 1 342 nm和1 064 nm激光的被动调Q,得到脉宽分别为29 ns和22 ns的脉冲序列。理论分析认为,纳米Ge晶粒形成的界面态和缺陷态对1 342 nm激光产生的饱和吸收作用,是导致被动调Q的主要原因。

By ratio-frequency (RF) magnetron sputtering technique and thermal annealing, the nanometer Ge mosaic SiO2 (nc-Ge／SiO2) composite films have been prepared. The optical absorption of the films is analysed, obtained the optical band gap. Single beam Z-scan of the experimental results show that the the films have a feature of strong saturable absorption. As a saturable absorber into the LD end pumped Nd:YVO4 lasers, 1 342 nm and 1 064 nm laser passively Q-switched are achieved, got the pulse width are 29 ns and 22 ns pulse sequence, respectively. Theoretical analysis shows that the formation of interface states and defect states in nc-Ge／SiO2, which have a saturable absorption effect for 1 342 nm laser, are the main reason for passively Q-switched operation.