EPFL researchers have developed a chip-based laser that keeps a very stable frequency across its tested operating range, without needing active electronic control. Their research is published in the journal Nature Photonics.

Lasers provide the precise light needed for atomic clocks, quantum sensors, fiber-optic monitoring, coherent communications and distance measurements. These applications depend on lasers whose optical frequency remains exceptionally stable. The most precise systems often rely on bulky laboratory lasers, which limits their use in compact and portable technologies.

Semiconductor lasers offer a practical alternative. They are small, electrically powered and suitable for large-scale manufacturing. Their frequency, though, tends to fluctuate much more than that of the fiber lasers used in precision systems.