Researchers from the Columbia University School of Engineering and Applied Sciences have developed a method to create a high-power frequency comb that avoids the need for large and expensive lasers and amplifiers. The team’s discovery enabled the researchers to brings the power of the frequency comb on-chip, yielding a compact, high-power, multiwavelength light source. The researchers believe that the developed approach and system could find use in state-of-the art data centers, which are already using fiber optic links to transport data, yet still typically rely on single-wavelength lasers. “Data centers have created tremendous demand for powerful and efficient sources of light that contain many wavelengths,” said Andres Gil-Molina, now a principal engineer at Xscape Photonics. “The technology we’ve developed takes a very powerful laser and turns it into dozens of clean, high-power channels on a chip. That means you can replace racks of individual lasers with one compact device, cutting cost, saving space, and opening the door to much faster, more energy-efficient systems.” The origin of the work dates back a few years; researchers in Michal Lipson’s lab were working on a project to improve lidar technology, designing high-power chips that could produce brighter beams of light. The work ultimately yielded a chip-created frequency comb as the researchers sent more and more power through their chip. With this advancement demonstrated, the researchers opted to use a multimode laser diode in their system. These lasers are widely used in applications such as medical devices and laser cutting tools, and produce enormous amounts of light. However, the beam is “messy,” which makes it hard to harness for precise applications. This schematic illustration shows the diffractive element in the high-power microcomb source separating comb lines spectrally. Courtesy of Michal Lipson Lab. The researchers deployed a locking mechanism to purify the powerful but very noisy source. Their method relies on silicon photonics to reshape and clean up the laser’s output, producing a much cleaner, more stable beam. Once the light is purified, the nonlinear optical properties of the chip function to split the single, powerful beam into dozens of evenly spaced colors — a defining feature of a frequency comb. The resulting system combines the raw power of an industrial laser with the precision and stability needed for advanced communications and sensing. The demonstration of an on-chip frequency comb offers potential to improve upon the single-wavelength lasers that are used in contemporary data centers by promising to bring multi-beam capability to the most compact, cost-sensitive parts of modern computing systems, the researchers said. Further, beyond data centers, the same chips could enable portable spectrometers, ultra-precise optical clocks, compact quantum devices, and advanced lidar systems. The research was published in Nature Photonics (www.doi.org/10.1038/s41566-025-01769-z).