CLAP-NET: Bandwidth adaptive optical crossbar architecture

While the number of processing cores placed on individual silicon dies climbs towards hundreds, and even thousands of cores, there is growing demand for efficient and scalable on-chip interconnects. Offering many advantages over metallic interconnects, nanophotonic interconnects enable new design possibilities, however, nanophotonic interconnects also require an off-chip laser source, which is often wasted to insertion losses and periods of low network activity. We present a new optical crossbar architecture that leverages capabilities of nanophotonics to provide high-performance inter-core communication while maximizing utilization of the laser power by means of dynamic bandwidth and laser power reconfiguration schemes. We compare our architecture with other proposed optical crossbar designs according to power consumption, throughput, and latency. We evaluate the network using synthetic patterns to show approximately a 13% improvement in throughput can be achieved compared to other optical crossbar designs, and a 92% improvement compared to a conventional electrical flattened butterfly architecture.