Despite the slowdown of Moore's Law, applications from machine learning and edge computing to scientific computing and mobile computing continuously demand more performance under tighter cost, energy, and size constraints. Silicon-based photonic technologies advanced rapidly in the last two decades and have become promising solutions to complement electronic technologies. OPTICS (optical/photonic interconnects for computing systems) forum aims at discussing the latest advances in optics/photonics for computing systems, covering topics from fabrications, photonic devices, photonic circuits, architectures, system integrations, and design automation and optimization. The forum targets researchers and engineers working on optics/photonics, electronics, architectures, systems, applications and design automations. Topics to be discussed include but are not limited to: