Controller for all-optical low power/cost coherent receiver used in short-reach systems.

The ICT industry faces huge challenges in the following years in terms of the bit-rate scalability and energy-efficiency of current transceiver solutions for the next-gen intra-datacenter, 5G fronthaul and access networks, rapidly extending their deployment. A key bottleneck is the cost and power consumption of available optical interconnects. To tackle these issues, we investigate the advancement of previously proposed all-optical solutions to be implemented in all-optical transceivers, discarding most of the power-hungry and costly DSP currently utilized in coherent receivers. Examining the optical link requirements for the targeted access/DCI networks, we present the design steps for a novel controller for all-optical polarization demultiplexing with a low-power footprint. We develop algorithms for polarization tracking in optical signal transmission through the fiber-optic link. In addition, we also present alternative solutions for the crucial function of carrier recovery in coherent receivers based on optical phase-locked loops.