中文摘要：

采用射频磁控溅射技术和热退火处理方法制备纳米锗镶嵌二氧化硅（Ge-SiO2）薄膜.利用光吸收谱和X射线衍射谱对薄膜材料进行表征,得到薄膜的光学带隙为1.12 eV,纳米Ge晶粒的平均尺寸约为16.4 nm.将纳米Ge-SiO2薄膜作为可饱和吸收体插入激光二极管泵浦的平-凹腔Nd∶YVO4激光器内,实现1 342 nm激光的被动调Q运转,获得脉冲宽度约为40 ns,重复频率为33.3 kHz的调Q脉冲序列输出.根据实验现象并结合薄膜结构,认为纳米Ge-SiO2薄膜的界面态和缺陷态是产生调Q的主要原因.

英文摘要：

NC-Ge/SiO2 films are prepared by radio-frequency（RF） magnetron sputtering technique and thermal annealing.The films have been characterized by optical absorption spectra and X-ray diffraction.The optical band gap of samples is 1.12 eV,the average size of nanocrystalline germanium in the films is about 16.4 nm.The passive Q-switched operation of a laser diode pumped Nd∶YVO4 1 342 nm laser was achieved by inserting the nc-Ge/SiO2 films as the saturable absorber into the plane-concave resonator.The pulse train with average pulse duration of 40 ns、repetition rate of 33.3 kHz was obtained.With the experimental phenomenon and the structure of the films,the mechanism of samples as saturable absorber was analyzed,that the nc-Ge/SiO2 films defects and interface states are the main reason for generating the passively Q-switched operation.