【作者】 王少华；

【导师】 祝远锋；

【作者基本信息】 江西师范大学 ， 信息与通信工程， 2023， 硕士

【摘要】 自高锟提出光纤以来,光纤极大地改变了人类社会。随着时代的进步,人们对光纤性能的要求越来越高。空芯反谐振光纤作为空芯光纤的一种,由于具有低损耗、宽传输带宽、单模传输等优良特性,成为目前空芯光纤领域的研究热点。近年来,研究人员提出了许多新型空芯反谐振光纤,其应用领域也变得越加广泛。本论文设计了一些新型反谐振空芯光纤结构,通过有限元分析方法研究其传输特性的变化并优化了结构参数,以获得性能良好的空芯光纤结构。主要内容如下:（1）设计了一种新型负曲率反谐振空芯光纤结构,其包层由半圆管和圆管混合组成,对不同的嵌套方式进行了研究,利用有限元分析方法对这些光纤结构的泄漏损耗及双折射进行了仿真计算,发现设计的结构能够实现低损耗及高双折射特性,通过对比选出了性能最佳的嵌套方式,进一步研究了结构参数对该光纤结构光学特性的影响。仿真结果表明,优化后的负曲率反谐振空芯光纤结构在1.55μm处的x和y偏振基模的泄漏损耗分别为4.25×10^-4d B/m和1.63×10^-3d B/m,对应的双折射系数为2.54×10^-5。（2）为了减少光纤结构缺陷引起的副作用,论文提出了将正、负曲率包层相结合来构建空芯光纤的思路,设计了一种部分负曲率反谐振空芯光纤结构,光纤具有多个反射层,且没有横向节点,论文利用正、负曲率包层中的包层模与纤芯高阶模相位匹配耦合来滤除高阶模,在多谐振层下实现了低损耗单模运转。仿真结果表明,此结构在1.07μm¹.524μm的宽带范围内,x和y偏振基模的泄漏损耗分别小于5.36×10^-3d B/m和1.0×10^-3d B/m,且x和y偏振基模的优值分别达到2547和22596。更多还原

【Abstract】 Since Gao Kun proposed optical fibers,they have greatly changed human society.With the progress of the times,people’s requirements for the performance of optical fibers are becoming higher and higher.As a kind of hollow-core fiber,hollow-core antiresonance fiber has become a research hotspot in the field of hollow-core fiber due to its excellent characteristics such as low loss,wide transmission bandwidth,and single-mode transmission.In recent years,many new hollow-core antiresonance fibers have been proposed,and their applications have become more and more extensive.In this paper,some new hollow-core antiresonance fiber structures are designed.By finite element analysis method,the transmission characteristics are studied and the structural parameters are optimized,so as to obtain the hollow-core fiber structures with good performance.The main contents are demonstrated as follows:（1）A new negative curvature antiresonance hollow-core fiber structure is designed,whose cladding is composed of semi-circular tube and circular tube.Different nesting modes are considered,and the leakage loss and birefringence of these fiber structures are simulated by the finite element analysis method.It is found that the designed structure can achieve low loss and high birefringence characteristics,and the best nesting method is selected by comparison.The influence of structural parameters on the optical characteristics of the fiber structure is further studied.The simulation results show that the limiting losses of the x and y polarization fundamental modes of the optimized negative curvature antiresonance hollow-core fiber structure at 1.55μm are4.25×10^-4d B/m and 1.63×10^-3d B/m,respectively.The corresponding birefringence coefficient is 2.54×10^-5.（2）In order to reduce the side effects caused by structural defects of fiber,this paper proposes the idea of combining positive and negative curvature cladding to construct hollow-core fiber,and designs a partially negative curvature antiresonant hollow-core fiber structure.The fiber has multiple reflective layers and no transverse nodes.In this paper,the cladding mode in the positive and negative curvature cladding is coupled with the high order mode of the core to filter out the high order mode.Low-loss single-mode operation is realized under multiple resonant layers.The simulation results show that the leakage losses of the x and y polarization fundamental modes are less than 5.36×10^-3d B/m and 1.0×10^-3d B/m,respectively,in the wide band range of1.07μm¹.524μm.The figure of merit of the x and y polarization fundamental modes reached 2547 and 22596,respectively.更多还原