Supercomputers capable of delivering Exaflops performance are envisioned to become a reality by the end of this decade. In order to provide the enormous communication bandwidth that is necessary, millions of optical interconnects will have to be deployed to connect together racks, modules and chips. Such massive level of parallelism will require monolithic integration of deeply scaled silicon nanophotonics devices in close proximity with transistors by utilizing the latest CMOS technology. This talk will discuss the physics and practical application of silicon nanophotonic devices, challenges in integration, and the frontiers of optical physics enabled by nanoscale engineering.