Researchers at the National Institute of Standards and Technology and their colleagues have demonstrated a new way to generate a miniature tape measure for light. Unlike previous designs, it can make high-quality optical measurements without needing to be tethered to bulky laboratory equipment.
The new device could help revolutionize ultraprecise mobile timekeeping and provide navigation signals for drones, cars, submarines, and other vehicles when GPS is either unavailable or has been jammed, according to the researchers.
The miniature instruments, known as microchip frequency combs, generate a spectrum of precise, evenly spaced colors that act like tick marks on a ruler to measure the frequencies of light with extraordinary accuracy.