Variation-aware adaptive tuning for nanophotonic interconnects

Short-reach nanophotonic interconnects are promising to solve the communication bottleneck in data centers and chip-level scenarios. However, the nanophotonic interconnects are sensitive to process and thermal variations, especially for the microring structures, resulting in significant variation of an optical link's bit error rate (BER). In this paper, we propose a power-efficient adaptive tuning approach for nanophotonic interconnects to address the variation issues. During the adaptive tuning process, each nanophotonic interconnect is adaptively allocated just enough power to meet the BER requirement. The proposed adaptive tuning approach could reduce the photonic receiver power by 8% - 34% than the worst-case based fixed design while achieving the same BER. Our evaluation results show that the adaptive tuning approach scales well with the process variation, the thermal variation and the number of communication nodes, and can accommodate different types of NoC architectures and lasers.