结构参量对脉冲高斯光束布拉格衍射特性的影响  

Influences of Geometry Parameter on the Bragg Diffraction by Volume Gratings of a Pulsed Gaussian Beam

作　　者：闫爱民[1] 刘德安[1] 周煜[1] 栾竹[1] 刘立人[1] 

机构地区：[1]中国科学院上海光学精密机械研究所信息光学实验室,上海201800

出　　处：《中国激光》2006年第11期1517-1521,共5页Chinese Journal of Lasers

基　　金：国家自然科学基金(60177106);国家科学技术部(2002CCA03500)资助项目

摘　　要：利用二维耦合波理论,研究了体光栅对时间和空间都为高斯型分布的脉冲激光光束的衍射性质,得到了衍射和透射光振幅的解析表达式.讨论了体光栅的结构参量对衍射光束的空间和频谱强度分布以及衍射效率的影响.结果表明,体光栅的波长选择带宽和衍射光束带宽随着结构参量的增大而增大,衍射效率随着入射脉冲时间宽度的增大而增大,并趋于定值,结构参量值越小,达到饱和的速度越慢,饱和值越大.The diffraction properties of a volume grating for a pulsed laser beam with Gaussian-profile both in time and space domain are studied, using two-dimensional （2D） coupled-wave theory. Analytical expressions for the spatial and spectral profiles of the transmitted and diffracted beams are obtained. The influences of geometry parameter on the Bragg diffraction properties and the diffraction efficiency of the pulsed Gaussian beam are discussed. It is shown that the Bragg selectivity bandwidth and the diffraction bandwidth of volume gratings are broadened when geometry parameter g increases. The diffraction efficiency increases when pulse duration increases and trends to a saturated value, the smaller the geometry parameter g is, the slower the saturating velocity is, and the larger the saturation value is.

关 键 词：衍射与光栅 布拉格衍射 耦合波理论 脉冲高斯光束 体光栅 

分 类 号：O438.1[机械工程—光学工程]