Optical Circuit Switching

Overview

Optical Circuit Switching (OCS) establishes physical light paths between fiber ports without electro-optical-electronic (O-E-O) conversion, routing photons directly through the switching fabric. This eliminates the power consumption, latency, and protocol-dependency penalties of conventional electrical packet switches. OCS is gaining rapid traction in AI-scale networking as GPU cluster sizes outgrow single-rack and single-pod boundaries, where the power and cost of electrical switching at 400G/800G line rates become prohibitive.

The OCP OCS Working Group, co-led by Google and iPronics alongside Lumentum, is driving open standards and management interfaces for OCS deployment. Commercial silicon photonics OCS products began shipping in 2025, with the technology moving from research to production data center use. OCS is positioned as a critical element of the emerging Silicon Photonics interconnect ecosystem for Gigawatt-Scale Data Centers.