少模光纤弯曲特性分析

Analysis of bending characteristics of few-mode fiber

摘要:

能够实现模分复用的少模光纤已经成为提高光纤通信传输容量的研究热点，其弯曲特性的分析具有重要意义。本文通过有限元建模分析研究普通阶跃少模光纤、环芯少模光纤以及椭圆型环芯少模光纤的弯曲半径、纤芯半径对其弯曲特性的影响。通过对比分析有效折射率、弯曲损耗以及有效模场面积三个性能指标，得出结论：弯曲对于三种少模光纤各阶模式的有效折射率影响较小；随着弯曲半径的增大，少模光纤的弯曲损耗呈现下降趋势，有效模场面积呈现增加的趋势；环芯少模光纤由于其特殊的纤芯结构使其具有更高的折射率差，椭圆型环芯少模光纤各模式间的重叠最小。本文的研究对少模光纤的结构设计及优化提供了有益的参考，为进一步研究利用少模光纤实现高质量的信号传输提供了理论基础。

Abstract:

Few-mode fiber that can realize mode division multiplexing has become a research hotspot to improve the transmission capacity of optical fiber communication, and the analysis of its bending characteristics is of great significance. In this paper, the effects of bending radius and core radius on the bending characteristics of ordinary step few-mode fiber, ring-core few-mode fiber, and elliptical ring-core few-mode fiber are analyzed by finite element modeling. Through the comparative analysis of the three performance indexes of effective refractive index, bending loss and effective mode field area, it is concluded that: the bending has less influence on the effective refractive index of the three types of few-mode fibers in each order mode; with the increase of the bending radius, the bending loss of the few-mode fiber shows a decreasing trend, and the effective mode field area shows an increasing trend; the ring-core few-mode fiber has a higher refractive index difference due to the special core structure, and the overlap between modes of elliptical ring-core few-mode fiber is minimal. The research in this paper provides a useful reference for the structural design and optimization of few-mode fibers, and provides a theoretical basis for further research on the use of few-mode fibers to achieve high-quality signal transmission.