Why OpenAI might be hedging its bets on quantum AI • The Register

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A silicon photonics play? Exotic quantum AI use cases aside, there are other technologies OpenAI could be pursuing for which Bartlett just so happens to be an expert.

Most notably, Bartlett's former employer PsiQuantum has been developing systems based on silicon photonics. This suggests his hire could be related to OpenAI's reported work on a custom AI accelerator.

Several silicon photonics startups, including Ayar Labs, Lightmatter, and Celestial AI have pushed the technology as a means to overcome bandwidth limits, which has become a limiting factor scaling machine learning performance.

The idea here is you can push a lot more data over a much longer distance with light than you can with a purely electrical signal. In many of these designs, the light is actually carried by wave guides etched into the silicon, which sounds an awful lot like "designing little race tracks for photons."

Lightmatter believes this technology will allow multiple accelerators to function as one without incurring a bandwidth penalty for data leaving the chip. Meanwhile Celestial sees an opportunity to vastly increase the amount of high-bandwidth memory available to GPUs by eliminating the need to co-package the modules directly adjacent to the accelerator die. Both of these capabilities would be attractive to a company working with AI systems at a massive scale.

Whether OpenAI will ultimately pursue quantum AI or silicon photonics remains to be seen, but for a company whose founder is no stranger to making long-shot investments, it wouldn't be the strangest thing Altman has backed. ®