Experimental Investigation on All-fiber Few-mode Recirculating Loop System (AF-FMRLS)

We demonstrate experimentally an all-fiber few-mode recirculating loop system (AF-FMRLS), enabling investigating the long-haul (looped) transmission performance of the mode-division multiplexing (MDM) technology. We locate the slowly squeezed area in the multi-input and multi-output (MIMO)-equalization algorithm which is suitable for the compensation operation of the proposed AF-FMRLS, significantly reducing the complexity of the digital signal processing for the MDM system.