Non-Hermitian bath model for arrays of coupled nanoresonators

Abstract

Nanophotonics systems have recently been studied under the perspective of non-Hermitian physics. Given their potential for wavefront control, nonlinear optics and quantum optics, it is crucial to develop predictive tools to assist their design. We present here a simple model relying on the coupling to an effective bath consisting of a continuum of modes to describe systems of coupled resonators, and test it on dielectric nanocylinder chains accessible to experiments. The effective coupling constants, which depend non-trivially on the distance between resonators, are extracted from numerical simulations in the case of just two coupled elements. The model predicts successfully the dispersive and reactive nature of modes for configurations with multiple resonators, as validated by numerical solutions. It can be applied to larger systems, which are hardly solvable with finite-element approaches.

A Series of Avoided Crossings of Resonances in the System of Several Different Dielectric Resonators Results in Giant Q-Factors

“…In a single silicon disk with permittivity = 12, the Q-factor reaches Q ≈ 1.5 • 10 2 for h 1 /r = 1.4157, as Figure 1b shows. Along with this, the ACR approach to boosting the Q-factor has been developed for systems of photonic molecules owing to coupling between resonators [12,35,[43][44][45][46][47][48][49][50]. In particular, strong enhancement of the Q-factor has been achieved for two identical coaxial disks [47,51].…”