Gazettabyte is asking industry figures for their thoughts after attending OFC 2026 in Los Angeles. First contributions from Maxim Kuschnerov of Huawei, Broadcom’s Near Margalit, and Corespan’s William Koss.
Maxim Kuschnerov, Senior Director R&D at Huawei
OFC 2026 stood out as the most substantial and extraordinary OFC in recent times.
We saw a tectonic shift as topics that had been developed and discussed for years finally became reality. Optics for AI scale-up went from a possibility to a commitment with the Nvidia Feynman generation and will be standardised in a new multi-source agreement, the OCI MSA, that proposes 4x50G non-return-to-zero (NRZ) signalling using micro-ring resonators.
New form factors received significant momentum, with Nvidia firmly betting on co-packaged optics (CPO) for AI scale-up and scale-out architectures, while Arista spearheaded a next-order-of-magnitude increase in pluggable modules through its XPO MSA.
The XPO MSA features a 4x density increase and liquid cooling, potentially enabling operation beyond 400W per pluggable.
Lastly, 400G per lane optical PAM4 materialised with Broadcom’s Taurus DSP, with first-module vendors showing very good performance, supporting the assumption of KP4 forward-error correction (FEC).
The OFC technical sessions and exhibition showcased a wide variety of material options for optical modulators.
The firm Coherent demonstrated the first 400-gigabit transmission over a silicon photonics Mach-Zehnder modulator using a standard CMOS process, which on paper was supposed to signify a decisive potential win over the more niche thin-film lithium niobate and indium phosphide for high baud rates. However, the optoelectronic bandwidth was only 70GHz, and performance was worse than that of their electro-absorption modulated laser (EML).
Conversely, Nvidia’s 200G per lane DR8 module based on its micro-ring resonators demonstrated superior performance, with error floors down to 1e-14, surpassing the EML solution.
The most likely realisation of co-packaged optics for scale-up will be silicon photonics micro-ring resonators, but VCSELs will put up a good fight.
High-temperature tolerance 2D VCSEL arrays were demoed at the show, and the supply chain is broad enough to support a solid alternative to silicon photonics. The 1060nm single-mode devices over multi-core fibre could indeed be an interesting solution, enabling longer reach.
Technical papers at the show detailed highly interesting results on 400G per lane barium titanate (BTO), lithium tantalate, and even graphene, which made a comeback at lower rates. Although these alternatives pose no immediate threat to the supply chains for thin-film lithium niobate (TFLN) and indium phosphide, they represent significant achievements.
Coherent transceivers also stand to benefit from next-generation form factors like XPO, enabling half-band modules in which four pluggables cover the entire C+L band. Ciena’s multi-rail concept, with dense inline amplifiers and full C+L-band transponder cards, pushes this concept even further, enabling a seamless rollout of long-haul capacity, fibre by fibre, without the need for wavelength-selective switching in these high-capacity, AI-driven backbone networks.
Optical circuit switches are the final technology to emerge from decades of research and niche markets. Optical circuit switches are becoming a high-impact product with significant backlogs and deployed across various use cases, such as spine switching, scale-up pods, and potentially even long-haul fibre-based protection switching.
Near Margalit, President and General Manager of the Optical Systems Division at Broadcom
At OFC, what stood out to me was how much Nvidia has invested in the co-packaged optics supply chain.
Additionally, I learned that lithium niobate is ready for 400 gigabit per lane. However, no one had a really good OFC 400 gigabit link demo.
William Koss, CEO of Corespan Systems
What a difference comparing my last visit, at OFC 2024, to this year’s OFC. There was so much more energy around this time.
Co-packaged optics or the death of copper was a big topic. Copper is not going away anytime soon, but the trend towards all-photonic solutions is emerging.
There is still a long way to go with co-packaged optics. I visited several suppliers, and there wasn’t much new, as they are still trying to get what they have into high-volume production.
Co-packaged optics is hard. There is science and tradecraft in knowing how to use it.
OFC 2026 was also the year of the optical switch. I visited seven companies with optical switches at the show: Coherent, Lumentum, iPronics, Huber-Suhner (Polatis), Calient, Accelink and Salience Labs. I even met Ming Wu at the show, founder of nEye Systems, so that’s eight optical circuit switch vendors I know of. All the various technology options were present.
I thought Arista’s Andy Bechtolsheim’s announcement of a liquid-cooled pluggable (XPO) was the most surprising news. AI has become so power hungry that we are using liquid cooling for pluggable optics!
Nvidia has had such a large impact on the optical industry that vendors are now quoting “scale-across” alongside scale-up and scale-out.
I clearly see the benefits of hollow-core fibre (HCF). It becomes a very nice fibre plant for the data centre and can be used for PCI Express (PCIe) as SerDes speeds range from 32G to 64G to 128G.
Distance is better with the loss budget, and hollow-core eliminates the need for coherent systems inside the data centre.
That might be a surprising revelation to watch: hollow-core fibre versus coherent optics in the data centre.