中国激光, 2017, 44 (4): 0406002, 网络出版: 2017-04-10
轨道角动量模式在柚子型微结构光纤中的传输 下载: 555次
Transmission of Orbital Angular Momentum Modes in Grapefruit-Type Microstructure Fiber
光纤光学 轨道角动量 有限元法 柚子型微结构光纤 有效折射率差 模式传输 fiber optics orbital angular momentum finite element method grapefruit-type microstructure fiber effective refractive index difference mode transmission
摘要
研究了轨道角动量(OAM)模式在柚子型微结构光纤(MOF)中的传输。光纤纤芯周围存在一层直径为3 μm的柚子型空气孔, 由于空气孔与光纤纤芯之间存在较大的折射率差, 传输的光被局限在纤芯中, 从而形成稳定的传输模式。通过有限元法对光纤中的矢量本征模式进行模拟, 得到了模式的有效折射率和模场分布。结果表明, MOF在630 nm波长附近可支持10个OAM模式传输, 各模式间的有效折射率差达到0.01以上,较大的有效折射率差可抑制光纤中各模式间的相互耦合, 从而提高OAM模式在光纤中的传输性能。实验中利用特殊设计的光学旋涡达曼光栅对在光纤中传输1 m的OAM1,1和OAM-1,1模式进行解调。
Abstract
The transmission of orbital angular momentum (OAM) modes in grapefruit-type microstructure fiber(MOF)is studied. The fiber core is surrounded by grapefruit-type air holes with diameter of 3 μm. The refractive index difference between fiber core and air hole is large, so that the transmission light can be concentrated into the core and stable modes can be formed. Based on the finite element method, vector eigenmodes in the fiber are analyzed. The effective refractive indexes and the mode filed distributions of these modes are obtained. The results show that the transmission of ten OAM modes can be supported around the wavelength of 630 nm. The effective refractive index differences among OAM modes are larger than 0.01. The large effective refractive index difference can suppress mutual coupling among different modes, and improve the transmission performance of OAM modes in fiber. In addition, we use the special designed optical vortex Dammann gratings in experiments to detect the OAM1,1 and OAM-1,1 modes after transmitting for 1 m in MOF.
乔文, 高社成, 雷霆, 吉虹, 阮银兰, 谢振威, 杨传武, 袁小聪. 轨道角动量模式在柚子型微结构光纤中的传输[J]. 中国激光, 2017, 44(4): 0406002. Qiao Wen, Gao Shecheng, Lei Ting, Ji Hong, Ruan Yinlan, Xie Zhenwei, Yang Chuanwu, Yuan Xiaocong. Transmission of Orbital Angular Momentum Modes in Grapefruit-Type Microstructure Fiber[J]. Chinese Journal of Lasers, 2017, 44(4): 0406002.