PT-axisymmetric photonic nanostructures

Abstract

Optical Parity-Time (PT-) symmetric systems support unusual properties. When the symmetric coupling between internal modes is broken the system becomes strongly unidirectional resulting in novel effects such as asymmetric reflections, invisibility or asymmetric mode coupling. Here, we propose a new class of nanophotonic PTaxisymmetric systems which lead to an extreme field enhancement and high localization at the P-symmetry center when the coupling of inward propagating waves is favored due to the asymmetric radial coupling. We expect the effect to have direct applications such as rendering broad aperture lasers into bright and narrow output beam sources.