Spotlight on Optics has featured our recent Optics Express paper titled "Experimental demonstration of broadband Lorentz non-reciprocity in an integrable photonic architecture based on Mach-Zehnder modulators", coauthored by Ph.D. student Qi Li and Prof. Keren Bergman of Lightwave Research Lab. In this paper we present a practical solution to the problem of optical isolation, one of the most critical problems in modern photonics. An optical isolator allows light to pass through in one direction but blocks it in the other, thereby acting as the optical analogue of the electronic diode. Because such a device induces a preferred direction for light, it must necessarily break an important symmetry of Maxwell's equations known as Lorentz reciprocity. This is an extremely difficult task, and the effort to find a solution, especially in the realm of "on-chip" photonic integrated circuits, has generated intense research activity in the past decade.
https://www.osapublishing.org/spotlight/summary.cfm?uri=oe-22-14-17409