Coiling Size Dependence of Group Delay Spread in Coupled Multicore Fibers Without Intentional Twisting

Abstract

Coiling size dependence of group delay spread (GDS) in coupled multicore fibers (MCFs) without intentional twisting is investigated by using a coupled-wave theory. It is shown that the GDS does not simply decrease with increasing bending radius and the optimum coiling size to decrease GDS depends on a core-to-core distance of MCFs. It is also found that a coupled MCF with a trench-assisted profile is suitable for realizing lower GDS with higher spatial density compared with a coupled MCF with a step-index profile.