Multilayer optical interconnects design: switching components and insertion loss reduction approach

The next generation of chip multi-processors point to the integration of thousands of processing cores, demanding high- performance interconnects, and growing the interest in optically interconnected networks. In this article we report on an interlayer silicon-based switch design that switches two channels simultaneously from an input waveguide into one of the two output ports. The introduced interlayer switch allows to design interconnects with previously unattainable functionality, higher performance and robustness, and smaller footprints with low insertion loss (< 1 dB), and high extinction ratio (> 18 dB). Interlayer switching combined with wavelength-routed and circuit-switched networks yield a low latency and low- loss interconnect architecture. Quantitative comparison between the proposed interconnect architecture and other reported structures in terms of loss, number of wavelengths and microring resonators reveals the proficiency of our design. For a 64-core interconnect implemented in 4 layers, the proposed architecture indicates an average loss reduction up to 42% and 43% with respect to single-layer lambda-router and GWOR.