Boosting optical non-reciprocity at the surface

The miniaturization of non-reciprocal devices for on-chip optical isolator integration calls for further technological development to increase efficiency over presently available products. Our previous study on Bi-substituted lutetium iron garnets showed that surface reconstruction resulted in significant changes in the density of states, leading to a significant enhancement in Faraday rotation. Subsequent studies via UV and visible optical, XPS, and magnetic circular dichroism have provided a deeper understanding of the role of the surface in electronic transitions responsible for the Faraday effect. These results will be presented at the conference and complementary density functional theory analysis, revealing significant changes in Fe and Bi densities of states at the surface. This study provides a valuable tool for improved materials technology towards the on-chip integration of non-reciprocal devices in optical circuits.