PsiQuantum says its silicon-photonics optical switch loses just 1.2 dB of light in lab tests, a result that could help data centres move information between AI processors with less signal loss. The trade-off for now: its demonstrated switch has only eight inputs and eight outputs, far fewer than competing devices.
Watch Desk analysis
What happened
The 8×8 prototype passes light directly between fibres without converting it to electrical signals or using an amplifier. Tom’s Hardware reports that it recorded 1.2 dB typical insertion loss, under 3 milliseconds to reconfigure and 40 dB of crosstalk in the company’s lab tests. PsiQuantum says a 64×64 version has been taped out, with a 72×72 device in development. Tom’s Hardware’s report says samples and testing kits have gone to several computing companies, including GPU vendors and hyperscalers.
Why it matters
AI clusters need to move data between GPUs quickly, and every conversion between optical and electrical signals adds power use and latency. Optical circuit switches can provide direct light paths; lower signal loss may make those paths more practical as networks grow.
The early comparison is promising, not a clean victory lap. The reported 1.2 dB is a company lab result, while the prototype’s eight-port scale trails alternatives including Google’s 136-port switch and other devices with 32 or more ports. PsiQuantum’s larger designs will show whether low loss survives the climb in scale.
Our read
This is an intriguing move from a company better known for quantum-computing ambitions into the very present business of AI networking. If the reported performance carries over to larger switches, it could matter; for now, the small prototype is a proof point, not a data-centre workhorse. The port count is doing a lot of the talking, and not all of it is flattering.
What to watch
- Whether PsiQuantum announces commercial products and larger devices in the coming months.
- Whether the 64×64 and 72×72 designs retain low signal loss without amplification.
- How the devices compare with established, higher-port-count switches in customer testing.
Discussion spark: Would you prioritise lower signal loss in a small optical switch, or higher port counts in a more mature design when building an AI data-centre network?
Sources and evidence
Watch Desk is operated by WittyWires as an independent cross-cutting AI news tracker. It does not speak for the organisations or people it covers.