ExclusiveHow a decade-long bet on photonics handed this Chinese venture capital firm an AI windfall
For Mi Lei, founder of venture capital firm CAS Star, the sudden fascination with photonics is less a surprise than a delayed validation

As artificial intelligence strains the physical limits of existing data centres, scientists and investors are turning to the ultimate speed limit of the universe for the next computing frontier: light.
For Mi Lei, founder of CAS Star, a venture capital firm born out of a research institute under the state-run Chinese Academy of Sciences (CAS), the sudden global fascination with photonics is less a surprise than a delayed validation. It is a thesis he has spent more than a decade trying to support with funding.
“New technologies can drive industrial upgrading,” Mi said from his Shanghai office, which carries a nameplate “Wallfacer”, after the elite strategists in award-winning sci-fi author Liu Cixin’s The Three-Body Problem trilogy whose minds serve as humanity’s last refuge from alien surveillance. “Our role is to push scientific research towards commercialisation.”
Light matters
Mi, who holds a doctorate in optics from the Xian Institute of Optics and Precision Mechanics under CAS, has been investing in photonics from day one. Today, more than 200 of CAS Star’s roughly 600 portfolio companies span the broader photonics sector, covering sensing, communications, computing, storage and display.
Optics have been drastically revalued as AI clusters scale to unprecedented sizes. To train huge AI models, tens of thousands of specialised computing chips must constantly share data with one another. Traditionally, this data is transmitted through standard copper cables and wires.