A Yale research team led by Professor Peter Rakich and graduate student Haotian Cheng has developed a groundbreaking chip-scale optical isolator that operates without the need for magnetic materials. Traditional optical isolators rely on magneto-optic effects, which are not compatible with standard silicon photonics. In contrast, the Yale team’s device uses acousto-optic interactions in a novel nonreciprocal multimode interferometer architecture, allowing light to travel in one direction while blocking it in the reverse. This approach enables seamless integration with CMOS technology, marking a significant advance for scalable photonic circuits.
The new isolator also achieves an exceptionally broad bandwidth of approximately 2 terahertz—several orders of magnitude greater than previous non-magnetic isolators. This performance paves the way for ultra-low-noise lasers, advanced sensing systems, and high-capacity communication networks on a silicon platform. The work has wide-ranging implications for photonic technologies in areas such as fiber-optic sensing, radar systems, and quantum information processing. Read more here.