Five-port silicon optical router based on Mach-Zehnder optical switches for photonic networks-on-chip

With the continuous development of integrated circuits, the performance of the processor has been improved steadily. To integrate more cores in one processor is an effective way to improve the performance of the processor, while it is impossible to further improve the property of the processor by only increasing the clock frequency. For a processor with integrated multiple cores, its performance is determined not only by the number of cores, but also by communication efficiency between them. With more processor cores integrated on a chip, larger bandwidths are required to establish the communication among them. The traditional electrical interconnect has gradually become a bottleneck for improving the performance of multiple-core processors due to its limited bandwidth, high power consumption, and long latency. The optical interconnect is considered as a potential way to solve this issue. The optical router is the key device for realizing the optical interconnect. Its basic function is to achieve the data routing and switching between the local node and the multi-node. In this paper we present a five-port optical router for Mesh photonics network-on-chip. A five-port optical router composed of eight thermally tuned silicon Mach-Zehnder optical switches is demonstrated. The experimental spectral responses indicate that the optical signal-to-noise ratios of the optical router are over 13 dB in the wavelength range of 1525-1565 nm for all of its 20 optical links. Each optical link can manipulate 50 wavelength channels with the channel spacing of 100 GHz and the data rate of 32 Gbps for each wavelength channel in the same wavelength range. The lowest energy efficiency of the optical router is 43.4 fJ/bit.