A Case Study of Signal-to-Noise Ratio in Ring-Based Optical Networks-on-Chip

Microresonators have been utilized to construct optical interconnection networks. One of the drawbacks of these microresonators is that they suffer from intrinsic crosstalk noise and power loss, resulting in Signal-to-Noise Ratio (SNR) reduction and system performance degradation at the network level. The novel contribution of this paper is to systematically study the worst-case crosstalk noise and SNR in a ring-based ONoC, the Corona. In the paper, Corona´s data channel and broadcast bus are investigated, with formal general analytical models presented at the device and network levels. Leveraging our detailed analytical models, we present quantitative simulations of the worst-case power loss, crosstalk noise, and SNR in Corona. Moreover, we compare the worst-case results in Corona with those in mesh-based and folded-torus-based ONoCs, all of which consist of the same number of cores as Corona. The quantitative results demonstrate the damaging impact of crosstalk noise and power loss in Corona: the worst-case SNR is roughly 14.0 dB in the network, while the worst-case power loss is substantially high at -69.3 dB in the data channel.