A tiny chip that works like a ruler for light

Scientists in the United States and New Zealand have shown a new way to make a ruler for light on a tiny chip. The work was announced on October 16, 2026, by the National Institute of Standards and Technology in the United States, known as NIST. Its researchers worked with colleagues from the University of Maryland and the University of Auckland in New Zealand. Earlier designs had to be connected to bulky laboratory equipment, but the new one can make high-quality measurements of light without it. According to the University of Auckland, which shared the news on October 8, the results were published in the journal Nature.

To understand the idea, think of an ordinary school ruler. Its black lines are evenly spaced, so you can put a pencil next to it and read how long the pencil is. Scientists measure light in a similar way, but instead of length, they measure its frequency, which is closely linked to its color. A tool called an optical frequency comb produces millions of precise colors, with exactly the same gap between each color and the next. These colors act like the marks on a ruler. By comparing other light with them, scientists can measure its frequency with extreme accuracy. That is why these tools are sometimes called light rulers or rainbow rulers.