NIST researchers demonstrate chip frequency comb without bulky support equipment

NIST and collaborating researchers demonstrated a microchip frequency comb that makes high-quality optical measurements without being tethered to bulky laboratory equipment. Frequency combs generate evenly spaced colors of light that serve as reference marks for measuring light frequencies and are essential components of optical atomic clocks. The researchers send light from two lasers around a tiny ring, where the light interacts with itself to generate the reference marks. This avoids the additional, power-hungry equipment needed by previous single-laser methods to produce stable marks. The advance could support mobile optical clocks for navigation when GPS is unavailable or jammed.