Design of Refractive Index Profile for Multimode Optical Fibers with Low Differential Mode Delay

Abstract

This work presents an alternative method for design of refractive index profile for silica GeO2-doped graded-index multimode optical fibers 50/125 with low differential mode delay (DMD), providing equalization between group velocities of selected guided modes. Here the objective function is represented as a sum of squares of deviations between points of current iteration group velocity map, which has been calculated over modes with particular orders, and certain reference group velocity value. During the objective function formation it is proposed to take into account only selected guided modes, that depend on the type of laser source and launch conditions. In the given article we represent some results of introduced method approbation with following simulation of fiber optic link based on proposed multimode fibers with low DMD under the core geometry variations.