Group velocity dispersion of a multicore fibre with 5 × 5 coupled cores for in-phase and out-of-phase supermodes

Abstract

In-phase and out-of-phase supermodes were selectively excited (with modal content >90%) in the wavelength range near 1030 nm in a silica multicore fibre with 5 × 5 coupled cores using a spatial light modulator. Group velocity dispersion (GVD) parameters of 21 ps2 km−1 and 14 ps2 km−1 at 1030 nm were measured for in-phase and out-of-phase supermodes, respectively, using an interferometric scheme. The numerically simulated GVD values agree with the experimental results. The calculated zero-dispersion wavelengths (ZDWs) of 1360 nm and 1180 nm for in-phase and out-of-phase supermodes are red-shifted and blue-shifted, respectively, compared to the ZDW of silica glass. The anomalous dispersion for the out-of-phase supermode is predicted in the telecommunication O-band near 1300 nm. The theoretical explanation of the difference in the wavelength-dependence of GVD for in-phase and out-of-phase supermodes is given.