title: Microbend-induced mode coupling in a graded-index multimode fiber.
abstract: We present a theoretical analysis of the mode coupling effects at a microbend along a graded-index (GI) multimode fiber (MMF). By matching the incident and excited mode fields at the microbend, we obtain the coupling coefficients among the guided modes at different microbending conditions. The theoretical results compare well with the experimental results from near-field measurements on a GI MMF subject to microbending. The usefulness of our theory is demonstrated with two applications: (i) an explanation of the operation principle of a wavelength-switchable fiber laser that contains a fiber Bragg grating in a GI MMF and (ii) quantification of the function of a microbend-based mode scrambler.
authors.affiliation: Network Technology Research Centre, School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 637553. lei.su@pmail.ntu.edu.sg
authors.forename: Lei
authors.initials: L
authors.lastname: Su
authors.forename: Kin Seng
authors.initials: KS
authors.lastname: Chiang
authors.forename: Chao
authors.initials: C
authors.lastname: Lu