Bandwidth is per-lane speed times lane count. Push speed and you hit the SerDes energy floor; push lane count and you hit fiber and connector cost. The new fact this year: the second wall arrived first.

Google reviews five TPU generations: an architecture set in 2017 survived the Transformer takeover and scaled 3600x. For optical readers, the key line: OCS, one of only two designs still unique to TPU, is what keeps a near-10K-chip machine alive, schedulable and deployable in stages. Power has now replaced cost as the new ceiling.

AI compute is growing 2.5X a year and electrical switching is hitting its limits. An OFC 2026 workshop showed how optical circuit switching (OCS), with its low latency and low power, is becoming a core technology for NVIDIA and the hyperscalers building next-generation AI supercomputers.

At OFC 2026, Lumentum announced a $2 billion strategic investment from NVIDIA and a multi-billion-dollar OCS deal. We break down how its 400G-per-lane EML tackles the copper bottleneck and how the new Greensboro fab supports its path to $2 billion in quarterly revenue.

Google's eighth-generation TPU splits into two architectures for the first time. STT breaks down how TPU 8t removes the training I/O bottleneck, and how TPU 8i uses large on-chip SRAM and OCS optical circuit switching to cut MoE inference network hops by 56%.

The OCP 2026 white paper, Lumentum's capacity lock-up race and Anthropic's 1-million-TPU deal mark the arrival of the optical direct-connect era. The full edition adds STT's golden-ratio formula, cube-position formula, a $22k OCS BOM, an 800G/1.6T BOM comparison and 13 stock view cards.

Lumentum nearly doubled revenue as EML and 1.6T products drove a 2,140 bps jump in operating margin. With demand far outstripping supply, how is Lumentum using NVIDIA's capital and new capacity to chase a $2B quarterly revenue target?

While the market waits for CPO, Google wrote its answer into 134,000 TPUs with Virgo Network. What holds this fabric up is not exotic packaging but an OCS optical switch six years in the making, and the winners are pluggable optical modules and their upstream suppliers.

Coherent hits its capacity-doubling target ahead of schedule. The 6-inch InP transition is now paying off, fueling 1.6T module and OCS revenue, while CPO developed in deep partnership with NVIDIA starts contributing revenue in late 2026.

Viavi's Q4 FY2026 beat the top of guidance on all three metrics, but the real signal is a new revenue engine: data center plus aerospace & defense drove nearly 70% NSE growth, and telecom capex is no longer the ceiling. Management pulled its $500M quarterly target forward a year as CPO test revenue began.

OCS has left the lab, but today it is less a market than a customer list with one name on it. Cignal AI's ECOC 2026 numbers: ~95% of OCS ports go into Google's TPU network, and whether GPU scale-up becomes the next killer app depends on CPO going multi-wavelength — an 8x port-count gap that will split the supply chain.

Optical circuit switching has stayed out of scale-up not because it fails to save power, but because it is two to three orders of magnitude slower than AI communication bursts. At OCP APAC, Linque showed a 64-channel silicon photonics OCS reconfiguring in 15 µs, clearing the “switch is too slow” hurdle. The other half—cutting transceiver lock time from milliseconds to nanoseconds—is the real battleground.

Coherent turned "AI scales on optics" into financial results: accelerating revenue, gross margin up in eight of nine quarters, and leverage down to 0.7x. The real variable is not demand but how fast 6-inch InP capacity ramps.

iPronics turns silicon photonics OCS architecture selection into a computable graph-theory benchmark. Verdict: Double Dilated Benes is today's practical 128×128 design, while Dilated Banyan performs best but hits the reticle limit. The question is no longer whether SiPh OCS can scale, but which architecture to pick.

Four industry heavyweights on one stage reached an unromantic consensus: demand isn't a bubble, technology isn't heading for a revolution, and the real battlefield is manufacturing. For Taiwan's supply chain, that means the winners will be decided by yield, process, and automation.

OCS has gone from Google's secret weapon to the OCP community's officially endorsed next-generation data center backbone. MEMS is shipping today, silicon photonics OCS is where the decisive battle will be fought, and GPU port-level reconfiguration is the next frontier.

Lumentum doubled revenue and broke 50% gross margin ahead of plan, turning "optics replacing copper" into reported numbers. The real signal is not one quarter: it hit its target a quarter early and is set to raise its entire financial model. Here are the three numbers STT will watch next quarter: OCS, gross margin and ultra-high-power lasers.

At JPM's 54th Global Technology Conference, Lumentum sent three key signals: optical cyclicality is dead, a three-stage growth engine (1.6T, scale-out, CPO) is lined up, and InP is the real bottleneck. NVIDIA has locked a huge share of capacity while other hyperscalers queue for prepaid contracts — the next capacity-lock battleground after HBM.

As AI traffic explodes, OCS (optical circuit switching) is displacing electrical switches at the spine layer. We break down the optical link challenges of the 1.6T era, the critical role of WDM and circulators, and why Coherent-Lite is poised to outclass IMDD.