During the past decade, laser frequency combs—extraordinarily precise tools for measuring frequencies (or colors) of light—have helped propel advances in timekeeping, trace-gas detection, and related physics research.

Although typical lasers operate at only a single or handful of frequencies, laser frequency combs operate simultaneously at many frequencies, approaching a million for some combs. These combs have very fine, evenly spaced “teeth,” each a specific frequency, which can be used like hash marks on a ruler to measure the light emitted by lasers, atoms, stars, or other objects. But frequency combs are usually bulky, yet delicate, lab instruments—about the size of a typical suitcase—and challenging to operate, which limits their use.

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