Accidental Rainbow-On-A-Chip Discovery Could Tame AI's Soaring Energy Demands

A team of Columbia University engineers may have stumbled on a key to cooling the AI industry's energy fever. While trying to boost the power of chips for LiDAR—laser-based sensing used most notably in self-driving cars—the researchers noticed something strange. "As we sent more and more power through the chip, we noticed that it was creating what we call a frequency comb," said Andres Gil-Molina, co-lead author of a new paper titled "High-power electrically pumped microcombs." That "comb" turned out to be more than a curiosity; it might be the building block for a new generation of ultra-efficient optical links that could someday replace energy-hungry electrical wiring inside AI datacenters.

The discovery centers on "microcombs," tiny ring-shaped resonators etched into silicon nitride. When light circulates inside these rings, nonlinear optical effects generate dozens of evenly spaced laser frequencies—a sort of miniature rainbow that can carry vast ...