Microring DWDM has long been seen as the densest but hardest-to-control route. NVIDIA's ECOC 2026 paper takes "too hard to control" apart piece by piece: nine rings find nine lasers on a chip that can't see the spectrum, then re-shuffle live through an 80°C temperature drift, with even the forwarded-clock handover running at zero bit errors.

Five NVIDIA publications are not isolated research but one vertically integrated weapon, deliberately split into four layers. STT merges them into a single technology map: how far this optical interconnect stack is from volume production, and what shape it bends the supply chain into.

Meta, Broadcom and AMD jointly define the OCI 200G line interface spec, betting scale-up optical interconnect on micro-ring DWDM, bidirectional single fiber, external lasers and NRZ. It is a buyer-supplier alliance taking on NVIDIA's vertical integration, and its external laser clause draws a clear spec for CW DFB and ELSFP suppliers.

Scale-up bandwidth is nearly an order of magnitude larger than scale-out, and once copper hits its limit, optics goes from option to the only answer. A full breakdown of AMD's Matthew Streshinsky talk at NTU, including how the 16-wavelength micro-ring chiplet works and the live Q&A.