Quantum-dot lasers are promising for integrated photonic circuits

Thousands of miles of fiber-optic cables crisscross the globe and package everything from financial data to cat videos into light. But when the signal arrives at your local data center, it runs into a silicon bottleneck. Instead of light, computers run on electrons moving through silicon-based chips—which, despite huge advances, are still less efficient than photonics.

To break through this bottleneck, researchers are trying to integrate photonics into silicon devices. They've been developing lasers—a crucial component of photonic circuits—that work seamlessly on silicon. In a paper appearing this week in APL Photonics, researchers from the University of California, Santa Barbara write that the future of silicon-based lasers may be in tiny, atomlike structures called quantum dots.

Such lasers could save a lot of energy. Replacing the electronic components that connect devices with photonic components could cut energy use by 20 to 75 percent, Justin Norman, a graduate student at UC Santa Barbara, said. "It's a substantialcutto global energy consumption just by having a way to integrate lasers and photonic circuits with silicon."