一种双模大模场面积多芯光纤的设计和特性分析

Design and Characteristic Analysis of a Dual-mode Large-mode-area Multi-core Fiber

提出了一种具有双模大模场面积的多芯光纤,建立了该多芯光纤的电磁场模型并采用有限元方法对其进行求解。基于该模型研究了光纤的模式特性和弯曲特性,系统分析了纤芯间距、纤芯半径和芯包折射率差对光纤模式特性和基模有效模场面积的影响。结果表明:通过引入空气孔并适当减少纤芯间距、纤芯半径和芯包折射率差,该光纤能实现严格的双模传输。保持双模传输时,通过增大纤芯间距,减小纤芯半径和芯包折射率差均有助于增大基模的模场面积。通过调整结构参数,在近似满足双模传输的条件下,光纤的基模模场面积在平直状态下可达到3 155μm2。

A dual-mode large-mode-area multi-core optical fiber is proposed in this paper,and the electromagnetic field model of the proposed fiber is constructed and solved by the finite element method.Both the mode and the bending characteristics of optical fiber are studied based on the model.The influence of the three parameters of core pitch,core radius and refractive index difference between core and cladding on the mode characteristics and effective mode field area of the fiber is analyzed systematically.The proposed multi-core fiber can realize strict dual-mode transmission by using air holes and reducing the core pitch,core radius and refractive index difference between core and cladding.When the optical fiber maintains dual mode transmission,the area of the mode field of the fundamental mode will increase with the increasing core pitch and decreasing fiber cores radius and the refractive index difference between core and cladding.If the dual-mode transmission is approximatively met,the mode field area of the fundamental modes of the straight fiber can reach 3 155μm2 by adjusting the structural parameters.