NIST researchers show microchip frequency comb free of bulky laboratory equipment
The microchip frequency comb uses two lasers and could help make ultraprecise mobile timekeeping possible, providing navigation signals when GPS is unavailable or jammed, NIST said.
AI illustrationResearchers at the National Institute of Standards and Technology (NIST) and their colleagues have shown a new way to make a microchip frequency comb, a miniature device that works like a tape measure for light. Unlike previous designs, the device can make high-quality optical measurements while free of bulky laboratory equipment, the institute said.
A frequency comb produces a spectrum of precise, evenly spaced colors. These act like the tick marks on a ruler and allow the frequencies of light to be measured with extraordinary accuracy.
Such combs are essential parts of optical atomic clocks, which produce extremely precise timing signals. According to NIST, the new device could help revolutionize ultraprecise mobile timekeeping. That in turn could provide vital navigation signals for drones, cars, submarines and other vehicles when GPS is unavailable or has been jammed.
The institute said mobile optical clocks could also be used for many applications beyond timekeeping, such as military navigation and oil, gas and mineral exploration.
In the new approach, scientists at NIST and JQI, a research partnership between NIST and the University of Maryland, send light from two lasers around a tiny ring called a microresonator. The light interacts with itself and produces the evenly spaced tick marks of a comb.
Earlier methods used a single laser. According to the researchers, those methods needed additional, power-hungry equipment to produce stable, high-quality tick marks, a problem the two-laser technique avoids.