Nonlinearity-Induced Reciprocity Breaking in a Single Nonmagnetic Taiji Resonator

Year: 2021

Authors: Munoz De Las Heras A., Franchi R.; Biasi S., Ghulinyan M., Pavesi L., Carusotto I.

Autors Affiliation: INO-CNR BEC Center and Dipartimento di Fisica, Universita di Trento, Trento, 38123, Italy; Nanoscience Laboratory, Dipartimento di Fisica, Universita di Trento, Trento, 38123, Italy; Centre for Materials and Microsystems, Fondazione Bruno Kessler, Trento, 38123, Italy

Abstract: We report on the demonstration of an effective, nonlinearity-induced nonreciprocal behavior in a single nonmagnetic multi-mode Taiji resonator. Nonreciprocity is achieved by a combination of an intensity-dependent refractive index and of a broken spatial reflection symmetry. Continuous wave power-dependent transmission experiments show nonreciprocity and a direction-dependent optical bistability loop. These can be explained in terms of the unidirectional mode coupling that causes an asymmetric power enhancement in the resonator. The observations are quantitatively reproduced by a numerical finite-element theory and physically explained by an analytical coupled-mode theory. This nonlinear Taiji resonator has the potential of being the building block of large arrays for the study of topological and/or non-Hermitian physics. This represents an important step towards the miniaturization of nonreciprocal elements for photonic integrated networks.


Volume: 15 (5)      Pages from: 054044-1  to: 054044-10

More Information: We acknowledge financial support from the Provincia Autonoma di Trento and the Q@TN initiative.S.B.acknowledges funding from the MIUR under the project PRIN PELM (20177 PSCKT). The authors would like to thank F. Ramiro Manzano, A. Calabrese and H. M. Price for continuous and insightful exchanges and E. Moser for technical support.
KeyWords: optical isolation; wave-guides; circulators; isolator; light
DOI: 10.1103/PhysRevApplied.15.054044