Photonic chip-based low-noise microwave oscillator. (https://pubmed.ncbi.nlm.nih.gov/38448599/)

These scientists wanted to create a way to make really accurate microwave signals using light. They used tiny lasers that are very stable and precise, and connected them to a small cavity to keep them steady. Then, they used a special type of light pattern called a dark soliton frequency comb to divide the laser frequencies. This allowed them to generate a microwave signal that was super accurate, with very little noise. This breakthrough could help make devices like GPS systems and communication tools even more precise and efficient.

Kudelin I., Groman W., Ji QX., Guo J., Kelleher ML., Lee D., Nakamura T., McLemore CA., Shirmohammadi P., Hanifi S., Cheng H., Jin N., Wu L., Halladay S., Luo Y., Dai Z., Jin W., Bai J., Liu Y., Zhang W., Xiang C., Chang L., Iltchenko V., Miller O., Matsko A., Bowers SM., Rakich PT., Campbell JC., Bowers JE., Vahala KJ., Quinlan F., Diddams SA. Photonic chip-based low-noise microwave oscillator. Nature. 2024 Mar 6. doi: 10.1038/s41586-024-07058-z.