400G optics
An earlier generation of optical modules running at 400 gigabits per second.
Ranks minor (33/100) — set apart by strategic relevance (40) and cross-layer reach (50).
Why it matters
It anchors the lower end of the optics roadmap.
Why now
AI fabrics are moving past 400G, illustrating the upgrade cadence.
If 400G optics runs short
Over-reliance on an aging grade limits fabric bandwidth.
In depth · editorial + model
Optical modules are the transceivers that turn a chip's electrical signals into pulses of light so data can move across a cluster at speed; 400G is an earlier generation of those modules, running at four hundred gigabits per second. It matters because it anchors the lower end of the optics roadmap — the baseline grade a great deal of installed networking was built around. Right now it is most useful as a marker of cadence: AI fabrics are already moving past it, which shows how quickly each optics generation is superseded.
The structural risk is over-reliance. Leaning on an aging grade caps how much bandwidth a fabric can carry, so a network stuck on 400G becomes a bottleneck even when the compute behind it keeps growing. The module makers most tied to this generation — Nokia and Celestica among them — sit on the part of the roadmap that newer builds are actively designing away from.
Who makes 400G optics
The companies exposed to 400G optics
How to think about it
- Optics generations turn over fast
What to watch
- 400G-to-800G transition pace
Frequently asked
What is 400G optics?
An earlier generation of optical modules running at 400 gigabits per second.
Why does 400G optics matter for AI?
It anchors the lower end of the optics roadmap.
Who makes 400G optics?
The companies the model tags as producers or suppliers of 400G optics: Nokia Corporation, Celestica Inc..
Which companies are most exposed to 400G optics?
Nokia Corporation, Celestica Inc. — 2 companies in total are mapped to 400G optics.
What happens if 400G optics runs short?
Over-reliance on an aging grade limits fabric bandwidth.
Where does 400G optics sit in the AI value chain?
400G optics sits in the Infrastructure layer of the AI value chain.
Go deeper on 400G optics
- The materials, geographies and policies it depends on — heat-mapped
- Substitutes, relief valves and the domino chains if it tightens
- The live tension score, momentum and news drivers
- Four levels of analysis — from plain-English to strategic
model v0.7.0 · research, not advice
Model scores are illustrative reads from our model of the AI value chain — not investment advice.