The Performance Analysis of Thermal Effect in Mesh-Based Optical Networks-on-Chips

Optical networks-on-chips (ONoCs) are the key technology for the sustainable development of multiprocessors system-on-chip (MPSoC) in the future. Micro-ring resonators (MRs) are widely used in ONoCs as key device to select and redirect optical signals. However, MRs have the inherent property of being sensitive to environmental temperature. With the fluctuation of environmental temperature, its resonance wavelength drifts, which can introduce more loss and crosstalk noise to ONoCs and make the network performance decline sharply. Therefore, it is very important to analyze the influence of thermal effect in ONoCs to solve this problem. In this paper, the theoretical models of loss and crosstalk noise changing with temperature are established from device level to network level, respectively. And a series of network performances of mesh-based ONoCs caused by thermal effect are systematically modeled and analyzed employing formal methods. Finally, we conduct case studies for mesh-based ONoCs using optimized crossbar optical router and crux optical router to evaluate the proposed method. The simulation results show that the performance of mesh-based ONoCs declines with the increase of temperature, such as the decrease of optical signal-to-noise ratio (OSNR) and the increase of bit error rate (BER), which severely limits the network scalability. The formal analytical models provide a criterion for the performance analysis of thermal effect in ONoCs. In addition, the formal methods have high portability and scalability, and can provide technical support for future research work.