Kerr-Nonlinearity Assisted Exceptional Point Degeneracy in a Detuned PT-Symmetric System

Abstract: Systems operating at exceptional points (EPs) are highly responsive to small perturbations, making them suitable for sensing applications. Although this feature impedes the system working exactly at an EP due to imperfections arising during the fabrication process. We propose a fast self-tuning scheme based on Kerr nonlinearity in a coupled dielectric resonator excited through a waveguide placed in the near-field of the resonators. We show that in a coupled resonator with unequal Kerr-coefficients, initial distortion from EP regime can be completely compensated. It provides an opportunity to reach very close to the EP in a coupled resonator with detuned resonant frequencies via tuning the intensity of the incident wave. Using time-modulation of the incident wave in nonlinear systems to control both the gain or loss, and resonant frequencies can be a possible approach to fully control the parameters close to an EP.