Supermodes in Coupled Multi-Core Waveguide Structures

Optical supermode dynamics are nowadays receiving an ever increasing attention in mode-division multiplexing applications. In this paper, we systematically analyze and characterize these modes in various structures based on coupled-mode theory. In particular, we investigate the structure of supermodes in honeycomb multi-ring arrangements of any size. In addition, we show that higher order supermodes in coupled few-mode multi-core waveguide arrays can be strongly affected by angle-dependent couplings, leading to different modal field profiles. Analytical solutions are provided for linear, rectangular, and ring arrays. Higher order supermodes are observed for the first time in a coupled few-mode three-core fiber system using the S2imaging method.