Silicon photonics for terabit/s communication in data centers and exascale computers

•Silicon Photonics Technology using sub micrometer SOI platform, is widespreading in the field of fiber optic interconnects.•Silicon Photonics mature platforms enable the development of high speed devices for datacenters.•Datacenter evolution and new applications (High Performance Computing) require Silicon Photonics to address new challenges.•This paper review these challenges, and the technologies being developed to address them: TSV integration, III-V/SOI integration for laser sources, high efficiency modulators and optical connector.•Co-packaging of Photonic Integrated Circuits with CMOS devices and development of Photonic Interposers for Optical Netowrk on Chips (ONoC) are the key concept for next generation datacenters and exascale computing systems. Silicon Photonics Technology using sub micrometer SOI platform, which commercially emerged at the beginning of the century, has now gained market shares in the field of fiber optic interconnects, from Inter-to Intra-Data Center communications. With growing demands in terms of aggregated bandwidth, scalability, transceiver form factor, and cost, Silicon Photonics is expected to play a growing role, especially with the foreseeable need to co-package photonic transceivers with next generation Ethernet switches. This new paradigm will be possible only with an evolution of existing Silicon Photonics manufacturing platforms, in order to solve the challenges of 3D packaging, laser integration, reflow-compatible optical connectors and high efficiency, low footprint modulators. Achieving these challenges may pave the way to Terabit scale communications in Data Centers and High Performance Computing Systems (HPC).