纳米硅镶嵌薄膜的光学性质及对1342nm激光的被动调Q  

Optical characteristic of nc-Si/SiNx film and its Q-Switching to 1342nm laser

作　　者：翟云[1] 王加贤[1] 王燕飞[1] 

机构地区：[1]华侨大学信息科学与工程学院,福建厦门361022

出　　处：《激光杂志》2011年第2期10-11,共2页Laser Journal

基　　金：福建省自然科学基金(2009J01291)

摘　　要：采用射频磁控溅射技术和热退火处理制备了石英衬底的纳米Si镶嵌SiNx(nc-Si/SiNx)薄膜。通过对薄膜的小角度X射线衍射和吸收光谱测试,确定了硅晶粒尺寸和光学带隙。采用Z-扫描技术研究了薄膜的三阶非线性光学特性,结果表明薄膜的非线性吸收属于双光子吸收。把nc-Si/SiNx薄膜作为可饱和吸收体插入LD抽运的Nd:YVO4激光器中,实现了1342nm激光的被动调Q,获得51 ns的激光脉冲。理论分析和实验结果表明,由于纳米Si的光学带隙大于1342nm光子能量,所以双光子饱和吸收导致了1342nm激光的被动调Q。The nanocrystalline silicon embedded in SiNx（nc-Si/SiNx） film is prepared by RFmagnetron sputtering technique and thermal annealing.The silicon grain size and optical band-gap of the film were detected according to low-angle X-ray diffraction（XRD） spectrum and absorption spectrum.The third-order nonlinear optical property of the film were probed by a Z-Scan Technique and experimental results show that the nonlinear absorption belonged to two-photon absorption.The passive Q-switching operation of 1342 nm laser was achieved and laser pulse with duration of 51 ns was obtained by inserting the nc-Si-SiNx film as saturable absorber into a LD pumped Nd：YVO4 laser.The the oretical analysis and experimental results indicated that because the optical band-gap of the nanocrystalline silicon is larger than photon energy of 1342 nm laser,therefore the two-photon saturable absorption caused passive Q-switching of 1342 nm laser.

关 键 词：激光技术 纳米硅薄膜 1342nm激光 被动调Q 双光子吸收 

分 类 号：TM248.1[一般工业技术—材料科学与工程]