Integrated Optical Interconnect Systems (iOIS) for Silicon Photonics Applications in HPC

Abstract

Integrated Optical Interconnection System (iOIS) is proposed for the first time for computing and communication systems by leveraging the 3DFabric platform. We propose the use of the second-generation COUPE (iOIS_COUPE2.0) as the optical engine with CoWoS-based composite interposer (iOIS_CI) as the integration platform for HPC, and networking applications. In COUPE2.0, a vertical broad-band coupler is integrated with the embedded microlens with a loss of 0.3 dB and alignment tolerance of ±10 μm. While in CI, a highly integrated electrical and optical interconnection layer can provide an electrical interconnect with 37.2× electrical bandwidth density with 0.19× energy consumption between ASIC and OE (compared with the conventional MCM solution with the micro-bump-based OE). The integrated single mode optical routing layer can yield propagation loss of 0.21 dB/cm and a 90-degree bending loss of 0.009 dB/turn. The multi-layer waveguide system features a 0.015 dB transition loss between adjacent layers and a beachfront bandwidth density up to 44.9 Tbps/mm for 100 Gbps single channel data rate. A specially designed optical interface between COUPE2.0 and CI not only provides low coupling loss of 0.015 dB but also paves the way for future heterogeneous integration of various non-silicon optical functional blocks. The broad-band vertical coupler in COUPE2.0 and waveguide system in CI are seamlessly integrated to provide performance and flexibility in CPO optical system design. As 3DFabric™-based CPO solution, iOIS can meet the diversified technology demands and yield a cost-effective manufacturable solution in alignment with foundry's 2.5D/3D roadmap.