Comparing analysis of guided modes excitation by fundamental mode injecting through the USF, DSF and NZDSF fibers coupled to conventional multimode fiber

摘要

Comparing analysis of guided mode excitation by fundamental mode injecting through the different types of singlemode fibers, coupled to conventional multimode fiber, is proposed. Multimode fiber excitation by singlemode laser source is represented in the form of splice of singlemode and multimode fibers. Mode power redistribution, depended on fiber type, fiber parameters and launch conditions, was researched. Following types of singlemode fibers were considered: usual step index fibers (USFs), dispersion shifted fibers (DSFs) and non-zero dispersion shifted fibers (NZDSFs). The overlap integrals method for calculating mode coupling coefficients at the splice of two optical fibers with mismatched parameters is applied. Modified Gaussian approximation for determination of waveguide parameters of spliced fibers with arbitrary index profile is used. Results of mode coupling parameters calculations at splice of mentioned types singlemode fibers and conventional multimode fibers are represented.