Optical Yagi-Uda nanoantennas

TL;DR

Optical Yagi-Uda nanoantennas are nanoscale devices inspired by radio antennas that enhance and direct light for applications in communications, sensing, and energy, with recent advances in design, fabrication, and tunability.

Contribution

This paper reviews recent theoretical and experimental developments in optical Yagi-Uda nanoantennas, highlighting their design, fabrication, and potential applications.

Findings

Efficient unidirectional light emission demonstrated

Extensions for broadband and tunable operation proposed

Applications in nanophotonics and photovoltaics discussed

Abstract

Conventional antennas, which are widely employed to transmit radio and TV signals, can be used at optical frequencies as long as they are shrunk to nanometer-size dimensions. Optical nanoantennas made of metallic or high-permittivity dielectric nanoparticles allow for enhancing and manipulating light on the scale much smaller than wavelength of light. Based on this ability, optical nanoantennas offer unique opportunities regarding key applications such as optical communications, photovoltaics, non-classical light emission, and sensing. From a multitude of suggested nanoantenna concepts the Yagi-Uda nanoantenna, an optical analogue of the well-established radio-frequency Yagi-Uda antenna, stands out by its efficient unidirectional light emission and enhancement. Following a brief introduction to the emerging field of optical nanoantennas, here we review recent theoretical and experimental activities on optical Yagi-Uda nanoantennas, including their design, fabrication, and applications. We also discuss several extensions of the conventional Yagi-Uda antenna design for broadband and tunable operation, for applications in nanophotonic circuits and photovoltaic devices.