Automatic Impairment-Aware Optical Path Switching in Multicore Fiber Link Based on Multiring Structure

We developed a novel multicore fiber (MCF) link based on a multiring structure composed of field programmable gate array (FPGA)-based optical switching units for highly reliable networks. The switching algorithm implemented on the FPGA in the unit has five high-functioning processes capable of coping with multiple link failures in the network. To verify the operations of this MCF link, we experimentally demonstrated automatic impairment-aware optical path switching when a failure occurred in an MCF link based on a two-ring structure. We were able to perform path recovery by switching within a relatively short period of time, 7.6 ms, which is sufficiently less than that required by ITU-T. The restoration path that substitutes for the failed working path was also optimized for low-loss transmissions by selecting the path having the minimum number of units through which a signal passes. These results indicate that the link will be useful for optical network designs that simultaneously need to ensure high capacity and reliable transmissions in businesses such as data centers.