一种支持130个轨道角动量模式稳定传输的反谐振光纤  

An Anti-Resonance Fiber Supporting Stable Transmission of 130 Orbital Angular Momentum Modes

作　　者：王震[1] 汪静丽[1] Wang Zhen;Wang Jingli(College of Electronic and Optical Engineering&College of Flexible Electronics(Future Technology),Nanjing University of Posts and Telecommunications,Nanjing 210023,Jiangsu,China)

机构地区：[1]南京邮电大学电子与光学工程学院、柔性电子(未来技术)学院,江苏南京210023

出　　处：《光学学报》2023年第23期72-81,共10页Acta Optica Sinica

基　　金：国家自然科学基金(12174199,61571237);江苏省自然科学基金(BK20221330,BK20151509)。

摘　　要：随着光纤通信技术的不断发展,基于轨道角动量(OAM)模式传输的空分复用技术引起了人们的广泛关注。本文提出了一种反谐振光纤(ARF),其结构主要分为三部分:内层高折射率紫水晶玻璃管作为环芯,其有效增大了纤芯与包层的折射率差,有利于OAM模式的稳定传输;中间层二氧化硅(SiO_(2))玻璃管起到调节色散的作用;外层负曲率管处于反谐振状态,进一步增强了对环芯光子能量的限制。该光纤可在1.5~1.7μm波段内稳定传输130个OAM模式。基于矢量有限元法(FEM)对ARF进行建模仿真与分析,结果表明,最大有效折射率差为6.08×10^(-3),最小色散变化率仅为0.43 ps·nm^(-1)·km^(-1),限制损耗(CL)维持在10^(-14)~10^(-8 )dB/m量级之间且最高模式纯度达到99.26%,有效模场面积最大值为187.38μm^(2),非线性系数最小值为0.87 W^(-1)·km^(-1),数值孔径(NA)均大于0.064。此外,还分析了光纤制作误差对其性能的影响。本文所设计的支持OAM模式传输的ARF在长距离光纤通信、高速信息传输等领域具有广泛的应用前景。Objective With the development of fiber communication,traditional multiplexing techniques cannot meet the demands for capacity.The utilization of orbital angular momentum(OAM)modes to carry information is a way to implement space division multiplexing(SDM)technology.This approach can greatly increase the capacity and spectral efficiency of fiber communication and show broad application prospects due to its unique advantages.Currently,transmitting OAM modes based on photonic crystal fiber(PCF)structures face problems such as difficulty in preparation and high loss.As research deepens,scholars attempt to solve these problems by utilizing anti-resonance fiber(ARF)to transmit OAM modes.The Fresnel reflection of the negative curvature tube in ARF cladding can enhance the confinement of the fiber core to the beam,further reducing the confinement loss(CL).Additionally,the preparation method of ARF is simpler than that of PCF,and fewer structural parameters make ARF easier to optimize for enhancing fiber performance.However,there is still a low number of transmission OAM modes in the current ARF design.Based on this,we propose an ARF composed of two sets of negative curvature anti-resonance tubes with different sizes.By introducing high refractive index materials in the ring core,more OAM modes can be transmitted,thereby improving the capacity of the fiber communication system.Methods An ARF is designed by introducing high refractive index materials into the ring core to organically combine total internal reflection and anti-resonance guiding mechanisms.In this ARF,the OAM mode is limited by total internal reflection in the ring core and the Fresnel reflection from the negative curvature tube of the cladding,which realizes the stable transmission of OAM modes in the fiber.Its structure includes a central air hole,an inner layer of high refractive index amethyst glass tube,an intermediate layer silica(SiO_(2))glass tube,and an outer layer of negative curvature tube.As the OAM mode number determines the capacity of the fib

关 键 词：轨道角动量 反谐振光纤 限制损耗 色散 光纤通信 

分 类 号：O436[机械工程—光学工程]