摘要
为解决一般涡旋光纤支持传输的轨道角动量模式数量少、阶数低和传输质量差的问题,设计了一种新型结构涡旋光纤。该光纤在制作紫晶掺杂管环和石英管环的基础上,利用管环嵌套的方式提高了空气填充率。利用基于有限元法的COMSOL Multiphysics软件对该结构光纤进行建模,并分析计算了其传输特性参数。结果表明,该光纤在不同的入射光波段以跳跃式稳定支持特定阶数的轨道角动量模式,在1500~1600 nm波长范围内可支持44个高阶轨道角动量模式稳定传输,包括较高阶数第31阶。对44个高阶模式进行详细分析发现,有效折射率差保持在10-3量级,色散平坦且色散变化均小于4.2 ps∙km^(-1)∙nm^(-1),模式纯度均大于94.5%,有效模面积最小值为122.78μm^(2),非线性系数最大值为0.89 km^(-1)·W^(-1),限制损耗维持在10^(-1)3~10-8 dB∙m^(-1)量级之间。当弯曲半径大于8 mm时,弯曲对该光纤能够支持的轨道角动量模式数没有影响,而当弯曲半径小于8 mm时,支持的模式数随着弯曲半径的减小而减少。
A vortex fiber with a new structure is designed to solve the problems of small numbers,low orders,and poor transmission quality of the orbital angular momentum modes supported by the general vortex fiber.On the basis of the fabrication of the amethystdoped tube ring and quartz tube ring,the fiber improves the air filling rate through the nested structure of tube rings.The designed vortex fiber is modeled by the software COMSOL Multiphysics based on the finite element method,and the transmission characteristic parameters are analyzed and calculated.The results reveal that the vortex fiber stably supports certain orders of orbital angular momentum modes in different incident light bands in a"jumping"manner.In the wavelength range of 1500–1600 nm,it can support 44 higherorder orbital angular momentum modes for stable transmission,including the 31storder mode.Moreover,the detailed analysis of the 44 higherorder modes demonstrates that the effective refractive index difference remains in the order of magnitude of 10−3,the dispersion is relatively flat,the dispersion variation is less than 4.2 ps∙km^(−1)nm^(−1),the mode purity is greater than 94.5%,the minimum effective mode field area is 122.78μm^(2),the maximum nonlinear coefficient is 0.89 km^(−1)·W^·(−1),and the confinement loss is maintained in the order of magnitude between 10−13 dB∙m^(−1) and 10−8 dB∙m^(−1).When the bending radius is greater than 8 mm,the bending has no effect on the number of orbital angular momentum modes that the fiber can support.When the bending radius is less than 8 mm,the number of supported modes decreases as the bending radius decreases.
作者
赵丽娟
姜焕秋
徐志钮
Zhao Lijuan;Jiang Huanqiu;Xu Zhiniu(School of Electrical and Electronic Engineering,North China Electric Power University,Baoding 071003,Hebei,China;Hebei Key Laboratory of Power Internet of Things Technology,North China Electric Power University,Baoding 071003,Hebei,China;Baoding Key Laboratory of Optical Fiber Sensing and Optical Communication Technology,North China Electric Power University,Baoding 071003,Hebei,China)
出处
《光学学报》
EI
CAS
CSCD
北大核心
2022年第22期13-23,共11页
Acta Optica Sinica
基金
国家自然科学基金(62171185,61775057)
河北省自然科学基金(E2019502177,E2020502010)
河北省省级科技计划(SZX2020034)
中央高校基本科研业务费专项资金项目(2021MS072)。
关键词
光纤光学
轨道角动量
涡旋光
涡旋光纤
空分复用
fiber optics
orbital angular momentum
vortex beam
vortex fiber
space division multiplexing
