光阑对暗中空涡旋光束轨道角动量的影响  

Effects of aperture on the orbital angular momentum of hollow vortex beam

作　　者：吕宏[1] 柯熙政[1] 

机构地区：[1]西安理工大学自动化与信息工程学院西安710048

出　　处：《中国科学：物理学、力学、天文学》2011年第8期932-941,共10页Scientia Sinica Physica,Mechanica & Astronomica

基　　金：国家自然科学基金(批准号:60977054);国防重点实验室基金(编号:9140C3601010901);国家高技术发展计划(编号:2008AAJ159);陕西省教育厅产业化项目;西安市科技攻关项目;陕西省知识产权局基金项目;陕西省自然科学基金(编号:2007F12)资助项目

摘　　要：基于推广的复高斯函数展开法,分析了具有轨道角动量的拉盖尔-高斯(Laguerre-Gaussian,LG)光束通过含光阑光学系统传输的解析公式,理论推导了空心LG光束在柱坐标系下光子轨道角动量密度函数及其态矢.对1阶LG涡旋光束通过光阑后的光场分布情况进行了数值分析,在两种典型含光阑系统物理模型下分析了遮拦比对不同波长LG光束传输特性的影响,研究了LG光束通过光学系统后的相位分布及轨道角动量密度变化.结果表明,光阑系统遮拦比对LG涡旋光束通过光阑后的传输特性的影响因光束波长不同而异,遮拦比对光束轨道角动量密度影响较大,对光束束径及光轨道角动量影响不明显.研究结果可为在空间光通信中利用涡旋光束光子轨道角动量编码信息提供理论依据.Based on the expended method of complex Gaussion functions,the recurrence propagation formulae of Laguerre-Gaussian（LG） beams with orbital angular momentum（OAM） through optical system with aperture is studied.The photon orbital angular momentum density function and state vector of LG beam are derived in cylindrical coordinates.The light intensity distribution of the first order LG beam through optical system with aperture was numerically simulated.The effects of the obscuration ratio on the propagation characteristics of different wavelength LG beams based on two optical physical models with an aperture,and the phase distribution and changes in the orbital angular momentum density of LG beam propagating through optical system were studied.Results show that the effects of the obscuration ratio on the propagation characteristics of LG beams are closely related to the wavelength.The obscuration ratio has much effect on the orbital angular momentum density,and the waist radius of LG beams has no obvious effect on the orbital angular momentum.These results provide some theoretical bases for the vortex beam with orbital angular momentum used in encoding of free space optical communication.

关 键 词：光束传输 光学涡旋 轨道角动量 光阑 

分 类 号：O436[机械工程—光学工程]