A Generic Optical Router Design for Photonic Network-on-Chips

Photonic network-on-chip (NoC) architectures are emerging as a new paradigm to interconnect a large number of processing cores at chip level, meeting the pressing demand for extremely high bandwidth and low power consumption. Optical routers, which are typically composed of silicon waveguides and optical switches, play a key role in an on-chip photonic interconnection network. In this paper, we propose a micro-ring-resonator (MRR)-based, scalable, and non-blocking passive optical router design, namely the generic wavelength-routed optical router (GWOR). We first introduce the four 4 × 4 GWOR router structures and then show how to construct GWORs of larger sizes by using the proposed 4 × 4 GWORs as the primitive building blocks. The number of MRRs used in the proposed GWOR is the least among the existing passive router designs for the same network size. In addition, we show that the power loss experienced on GWORs is lower than other comparative designs. Furthermore, to improve the bandwidth and fault tolerance capability of the GWORs, the redundant GWOR (RGWOR) structure is presented. RGWOR can provide multiple routing paths between each pair of input-output ports by cascading different types of GWORs.