OFC 2026 Preview: 400G per Lane — The Next Major Inflection in Optical Interconnects

We have been steadfast supporters of Optics since a year and a half ago, publishing in-depth Optics reports almost every month. Regarding this OFC and future Optics technology trends, we have a lot to discuss — especially today, when there is so much debate and speculation.

We released the GTC Preview last week — you can read them together.

AI clusters have scaled from hundreds to hundreds of thousands of accelerators, making optical interconnects a defining infrastructure bottleneck for continued cluster scaling. In 2026, the industry stands in front of the inflection point of the 200G-to-400G per lane transition — a doubling of lane speed that will simultaneously reshape modulation schemes, material platforms, and manufacturing capacity. Short-reach IMDD remains dominant, but the 1–20 km segment is opening a new market for Coherent Lite — one that was largely absent in the 200G era. This report traces the path from AI interconnect demand through the 200G/lane status quo and 400G/lane technology divergence, evaluates the competitive positioning of InP, SiPh, and TFLN material platforms in the new cycle, and maps the findings to six key industry themes and the associated value chain participants.

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I.Optical Interconnects: The Core Bottleneck of AI Infrastructure