PsiQuantum is showing customers a prototype optical circuit switch designed to route signals between GPUs in AI data centres without converting light into electricity and back. The idea is to ease a networking bottleneck as data centres link ever-larger clusters of processors, though the prototype’s performance claims are not independently established in the report.
Watch Desk analysis
What happened
PsiQuantum has spent a decade developing photonic quantum computers and optical chips. Now, Semafor reports, the company is pitching an optical switch that could route signals directly between server racks using light. PsiQuantum executive Robert Soderbery said the system could let separate racks behave like one, with connections as fast as those inside a rack.
The approach targets a costly detour in current optical networks: signals are converted into electrical form for routing, then converted back into light. PsiQuantum says its device avoids those conversions, with negligible energy use and almost no heat. Those are company claims about a prototype it has shown to prospective customers, not independent test results.
Semafor’s report also notes that Google is currently the only major hyperscaler using purely optical circuit switching in an AI data centre, with a system that uses tiny mirrors.
Why it matters
Training large AI models requires many GPUs to coordinate, and the links between them can become a limiting factor. Optical switching that cuts conversion steps could reduce energy and heat while helping data centres connect more processors. That is a practical AI-infrastructure play from a company better known for its quantum-computing ambitions.
Our read
This is a compelling crossover: photonics built for a quantum-computing company may find an earlier commercial test in the data-centre boom. But a prototype shown to customers is a promising proposal, not yet a working alternative at scale. The next useful evidence is a deployment with measured speed, power use and reliability. Light-speed networking still has to make it out of the demo room.
What to watch
- Whether PsiQuantum announces a customer or commercial deployment.
- Independent measurements of latency, energy use and heat.
- How its approach compares with existing optical switching systems.
Discussion spark: Should AI data-centre operators prioritise optical links to cut networking bottlenecks, even before the technology is proven at scale?
Sources and evidence
- Quantum computing company’s first breakthrough is in AI data centers | Semafor (28 October 2026, 16:26 UTC)
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