Design of 12 OAM-Graded index few mode fibers for next generation short haul interconnect transmission

Abstract

Abstract The exploitation of the spatial dimension in space division multiplexing (SDM) is a promising solution for increasing the transmission capacity and substantially improving the spectrum efficiency. Orbital angular momentum (OAM) is one of the most attractive approaches of SDM that observes increasing interest either in free space or in optical fiber communications. In this work, we design optimized graded index-few mode fibers (GI-FMFs) supporting 20 eigenmodes with high intermodal separation (≥1 × 10−4) between vector modes; hence limiting intermodal coupling and favoring the formation of 12 OAM modes. To the best of our knowledge, this is the highest OAM number reported in the well-known graded index fiber. We investigate numerically the effects of the shape parameter (α) on the supported vector modes and on the properties of OAM channels in the GI-FMFs. We evaluate their associated differential group delay (DGD) and purity. The selected designs are proposed as viable candidates for short haul connections.