Perturbing an exceptional point via photoconductive scatterer in a dielectric resonator array

Here, simulations of a photoconductive scatterer in a system of two parallel dielectric resonators operating at a non-Hermitian degeneracy, or exceptional point (EP) are explored. Systems operating at an EP exhibit unique characteristics such as increased sensitivity to low-level perturbation that can be exploited to enhanced sensing applications. To elucidate this functionality, two-dimensional eigenfrequency simulations of this novel system operating at an EP with the scatterer is used to introduce perturbations to the system. The EP is identified through the variation of two physical parameters viz. the distance of the scatterer from the resonators and the gap between the resonators. A systematic parametric sweep of these variables shows the distinctive characteristics of a system with EPs including a crossing of real eigenfrequencies, repulsion of imaginary eigenfrequencies, simultaneous mode excitation, self-intersecting Riemann sheets, and eigenvalue splitting in response to perturbation. These results show how this EP-based systems can be used to significantly improve sensitivity low-level light detection.