Computing systems, from HPC and data center to automobile, aircraft, and cellphone, are integrating growing numbers of processors, accelerators, memories, and peripherals to meet the burgeoning performance requirements of new applications under tight cost, energy, thermal, space, and weight constraints. Recent advances in photonics technologies promise ultra-high bandwidth, low latency, and great energy efficiency to alleviate the inter/intra-rack, inter/intra-board, and inter/intra-chip communication bottlenecks in computing systems. Silicon photonics technologies piggyback onto developed silicon fabrication processes to provide viable and cost-effective solutions. Many companies and institutes have been actively developing silicon photonics technologies for more than a decade. A large number of silicon photonics devices and circuits have been demonstrated in CMOS-compatible fabrication processes. Silicon photonics technologies open up new opportunities for applications, architectures, design techniques, and design automation tools to fully explore new approaches and address the challenges of next-generation computing systems. PHOTONICS (Photonics-Optics Technology Oriented Networking, Information, and Computing Systems) workshop presents the latest progresses and provides insights into the challenges and future developments of this emerging area.