Near-Zero Modal-Dispersion (NEMO) Coupled-Core Multi-Core Fibers

Abstract

We propose a design for coupled-core multi-core fibers that allows to achieve extremely low levels of modal dispersion. These fibers, which we dub NEar-zero MOdal-dispersion (NEMO) fibers, have an even number of cores regularly distributed on a circle, and the optimal design parameters follow from a simple condition independent of the number of cores. The modal-dispersion reduction trades off some of the fiber modemixing effectiveness, yet without compromising its beneficial property of mitigating nonlinear signal distortions. The semianalytical tool developed for this study allows to effectively characterize the effect of various types of perturbations to the ideal fiber structure.

Maximizing the Capacity of Graded-Index Multimode Fibers in the Linear Regime

“…pace-division multiplexing (SDM) has emerged as a solution to overcome the capacity limit of single-mode fibers (SMFs) [1]. Among the possible SDM approaches, multimode fibers (MMFs) [2][3][4][5] offer the highest spatial information density followed by coupled-core multi-core fibers (MCFs) [6][7][8][9]. Spatial density plays a critical role in maximizing opportunities for opto-electronic integration gains, and transceiver-specific integration is key to the overall value proposition of SDM.…”

“…For short-reach systems at 850 nm, new types of multimode fiber increasing bandwidth several-fold have been demonstrated: a multicore multimode fiber formed from a large number of single mode cores [3] or a larger core graded-index multimode fibers [21]. For highcapacity SDM systems at ~1.55 m, there has been significant progress on coupled-core MCFs with near-zero modal dispersion [8,9,22] up to 19 cores and on rescaled standard graded-index-core MMFs [23,24] up to 55 spatial modes. Here, we extend the latter approach to a much larger number of modes (up to 1000 spatial modestwice as many polarization modes) by scaling the core-cladding contrast and the core radius within a 125 m cladding.…”