Investigation of MDL accumulation in recirculating loop systems using coupled-core multicore fibres with a quasi mode scrambler

We propose a quasi mode scrambler to mitigate exaggerated MDL accumulation specific to recirculating loop systems. We measured accumulated MDL in a recirculating loop system using coupled-core multicore fibres and mode scrambler. Unlike PDL in uncoupled-core multicore fibres, accumulated MDL was not reduced by scrambling.