基于光子晶体光纤的轨道角动量模式的产生  

Generation of orbital angular momentum mode based on photonic crystal fiber

作　　者：曹家帅 贾宏志[1] CAO Jiashuai;JIA Hongzhi(School of Optical-Electrical and Computer Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China)

机构地区：[1]上海理工大学光电信息与计算机工程学院,上海200093

出　　处：《光学仪器》2022年第4期73-80,共8页Optical Instruments

摘　　要：为了让光纤中产生轨道角动量(orbital angular momentum,OAM)模式更加集成化,提出了一种利用光子晶体光纤(photonic crystal fiber,PCF)产生轨道角动量模式的方法。通过设计特殊的PCF,使其本征模的奇偶模传输速度不同,在传输一段距离后形成π/2相位差,从而产生OAM模式。该PCF由中心空气孔、二氧化硅环形层和外包层构成,其中外包层由两层圆形空气孔组成,每层圆的数目为2n+2个,对应产生n阶OAM模式。采用有限元法对所设计光纤进行了三维数值仿真分析,成功产生了+2、+3、+4、+5阶OAM模式。该PCF产生OAM模式的方法,满足了未来光纤通信系统集成化、小型化的趋势,在全光纤模分复用系统中有着潜在的应用前景。In order to make the orbital angular momentum(OAM)mode generated in the optical fiber more integrated,a method to generate the orbital angular momentum mode using photonic crystal fiber(PCF)is proposed.By designing a special PCF,the transmission speeds of the eigenmodes of the odd and even modes are different,and thus aπ/2 phase difference is formed after transmission for a certain distance to produce an OAM mode.The PCF is composed of a central air hole,a silica ring layer and an outer cladding layer.The outer cladding layer is composed of two layers of circular air holes.The number of circles in each layer is 2n+2,corresponding to the norder OAM mode.The finite element method was used to carry out three-dimensional numerical simulation analysis of the designed optical fiber,and the+2,+3,+4,and+5 orders of OAM modes were successfully generated.The PCF method for generating OAM modes meets the trend of future integration and miniaturization for optical fiber communication systems,and has potential application prospects in all-fiber mode division multiplexing systems.

关 键 词：光子晶体光纤 轨道角动量 光纤通信 

分 类 号：TN252[电子电信—物理电子学]