Multi-Core Optical Fiber with Stepped Single-Mode Cores. Part 1. Insulation with Solid Clads

Abstract

An optical fiber with several unrelated cores inside a common clad (multi-core fiber) is used to increase the capacity of linear paths of communication systems. The number of cores in one fiber is limited by mutual influences between them, to reduce which various design solutions are used. The aim of the work is to compare various multicore fibers and identify structures that allow placing the largest number of cores in a common shell with a standard diameter of 125 microns. In the first part of this paper, modeling of single-mode fibers with cores isolated by additional solid shells is carried out. As a result of modeling, the characteristics of the fundamental modes of the cores of each fiber are calculated – the distribution of the electric field strength, chromatic dispersion and the diameter of the field of the fundamental mode, a technique is proposed and an assessment of mutual influences is carried out, the maximum possible number of cores is determined. It is shown that the insulating clad reduces mutual influences and allows increasing the number of cores by reducing the distance between them.