Optical antennas

Abstract

Optical antennas are at the crossroads of photonics, material sciences and antenna engineering. Advances in electromagnetic modelling methods, in material science and in nanofabrication techniques have enabled tremendous achievements by researchers and technologists worldwide. The interest in nanoantennas has been largely fuelled by promises of real-world optical applications for which access to resolving subwavelength features is highly desired. Such applications include localised field enhancement, ultra-fast detection and sub-diffraction sensing. Furthermore, concepts of optical components inspired by reflectarrays, transmitarrays and metasurfaces have emerged to offer fine manipulation of optical beams at a subwavelength scale. As these developments mature and find their ways into future technologies, a new field of applications are emerging. The aim of this chapter is to introduce the fundamental concepts relevant to the understanding of optical antennas and provide a (non-exhaustive) review of recent developments.