AI-rewritten: This is a summary of an article from Phys.org, rewritten by AI (Qwen, running locally) to make it easier to read. The facts come from the original article – read it for the full story.

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Physicists have developed a new chip-based tool called an optical frequency comb that could lead to portable atomic clocks. Currently, measuring light frequencies requires large, bulky equipment that takes up significant lab space. This new device produces a rainbow of light frequencies spaced like tick marks on a ruler, allowing researchers to measure differences between colors easily. The team behind this invention includes scientists from the Joint Quantum Institute, the University of Auckland, and institutions in Maryland, California, and the Air Force Research Laboratory.

The breakthrough relies on a phenomenon known as parametrically driven cavity solitons, which involves circulating light from two lasers around a tiny ring called a microresonator. Previous attempts to make chip-based combs struggled with control and stabilization issues. The new design uses a technique nicknamed SParCS, where two lasers act as bookends for the comb’s frequencies. This arrangement creates more precise measurements by concentrating power at the edges of the frequency range, which are critical for determining the zero-frequency offset needed for accurate timing.

The researchers achieved self-alignment, locking all frequency lines into a single set of marks to create a "pristine ruler." Unlike older methods that required bulky gear to find specific offsets, this approach ensures the comb spans an octave with strong edge teeth. This advancement makes it viable for deployable atomic timekeeping, potentially enabling navigation systems independent of GPS and tools to map underground mineral deposits without relying on satellite signals.