The CPO era has officially begun, with Cignal AI forecasting a $1.5B opportunity by 2030. Beyond the push from Nvidia and Broadcom, STT argues that CoS packaging for high-power lasers is the hidden barrier that will decide who wins ELSFP volume production.

A major step for CPO external laser sources: at OFC 2026, Furukawa Electric showed an 8-channel TOSA delivering up to +25 dBm per channel, using a long-cavity design to solve high-power thermal limits and pave the way for 1.6T switch deployments.

The external laser source has gone from "one part inside a module" to a formal product category with specs, interoperability requirements and multiple competitors. Of the seven spec fields laid out at ECOC, power is just one; the real ticket is spec completeness and packaging throughput.

At ECOC 2026, Coherent skipped the CPO sales pitch and brought a working machine: a 6.4T NPO with its own ELSFP at 4.7 pJ/bit — laser included. LightCounting puts the crossover at 2031. The CPO debate is over; what remains is a fight over the slope.

Edgecore admitted 1.6T LPO is "not yet successful," so the stopgap is gone and CPO can no longer wait a generation. Three MSAs at OFC 2026 push CPO toward swappable engines, while SONiC only now has the models it needs. Hardware decides who ships; software decides who deploys at scale.

The light-source race has switched tracks: it's no longer about whose laser is brighter, but who can make billions of them by 2030 without spending 5 minutes of active alignment on each. At ECOC 2026, two sessions and 11 speakers delivered eight technology paths and an 18 dB bill.

Elaser's 2Q26 EPS tripled QoQ, but the real signal is its revenue mix: AI optics jumped from 32.7% to 45.5% in seven months. COSA is the cash cow, AOC the second engine, and its biggest bet, ELSFP, is still not in volume production. STT flags the three numbers to watch next quarter.

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.

Optical interconnects are moving from the lab to the factory. NVIDIA and Lumentum have built the first production-ready DWDM laser array, with 7.2% wall-plug efficiency and per-channel power held within ±0.8 dB. More importantly, system-level simulation quantifies what actually drives optical link cost, as copper's ceiling makes the alternative an economic necessity.

Generative AI is driving explosive compute demand, and silicon photonics is the key to breaking transmission limits. This recap breaks down TSMC's COUPE, Elaser's ELSFP packaging, multicore fiber and automated testing to map the optical supply chain's path to volume production.