Unidirectional and Wavelength Selective Photonic Sphere-Array Nanoantennas

TL;DR

This paper introduces a novel photonic sphere-array nanoantenna that achieves high directionality and wavelength selectivity by utilizing Fano-resonance, offering a low-loss alternative to plasmonic designs for photon detection and emission control.

Contribution

It presents a new design for photonic nanoantennas that combines directionality and wavelength selectivity with reduced metallic loss, based on Fano-resonance principles.

Findings

Achieves high directionality through tunable Fano-resonance.

Reduces metallic loss compared to plasmonic nanoantennas.

Provides design guidelines for photonic nanoantenna applications.

Abstract

We design a photonic sphere-array nanoantenna (NA) exhibiting both strong directionality and wavelength selectivity. Although the geometric configuration of the photonic NA resembles a plasmonic Yagi-Uda NA, it has different working principles, and most importantly, reduces the inherent metallic loss from plasmonic elements. For any selected optical wavelength, a sharp Fano-resonance by the reflector is tunable to overlap spectrally with a wider dipole resonance by the sphere-chain director leading to the high directionality. The work provides design principles for directional and selective photonic NAs, which is particularly useful for photon detection and spontaneous emission manipulation.