Q-factor enhancement in all-dielectric anisotropic nanoresonators

TL;DR

Introducing radially anisotropic claddings in all-dielectric nanoresonators significantly enhances their Q-factor by improving light confinement, with practical implementation via multilayered isotropic structures.

Contribution

Demonstrated that anisotropic claddings can boost Q-factors in dielectric nanoresonators and proposed a feasible multilayered design for realization.

Findings

Q-factor can be significantly increased with anisotropic claddings

Radially anisotropic claddings improve light confinement

Multilayered isotropic structures can realize the anisotropic cladding

Abstract

It is proposed and demonstrated that Q-factor of optical resonators can be significantly enhanced by introducing an extra anisotropic cladding. We study the optical resonances of all-dielectric core-shell nanoresonators and reveal that radially anisotropic claddings can be employed to squeeze more energy into the core area, leading to stronger light confinement and thus significant Q-factor enhancement. We further show that the required homogenous claddings of unusual anisotropy parameters can be realized through all-dielectric multi-layered isotropic structures, which offers realistic extra flexibilities of resonance manipulations for optical resonators.