Nanoantennas for visible and infrared radiation

TL;DR

Nanoantennas for visible and infrared light significantly enhance light-matter interactions at the nanoscale, enabling advanced applications in microscopy, energy, and sensing, with ongoing developments in design and material limitations.

Contribution

This review synthesizes current knowledge on optical nanoantennas, highlighting their plasmonic behavior, material constraints, and future research directions in a rapidly evolving field.

Findings

Nanoantennas enable strong light-matter interaction at nanoscale.

Plasmonic effects are central to nanoantenna performance.

Material and fabrication limitations influence design choices.

Abstract

Nanoantennas for visible and infrared radiation can strongly enhance the interaction of light with nanoscale matter by their ability to efficiently link propagating and spatially localized optical fields. This ability unlocks an enormous potential for applications ranging from nanoscale optical microscopy and spectroscopy over solar energy conversion, integrated optical nanocircuitry, opto-electronics and density-ofstates engineering to ultra-sensing as well as enhancement of optical nonlinearities. Here we review the current understanding of optical antennas based on the background of both well-developed radiowave antenna engineering and the emerging field of plasmonics. In particular, we address the plasmonic behavior that emerges due to the very high optical frequencies involved and the limitations in the choice of antenna materials and geometrical parameters imposed by nanofabrication. Finally, we give a brief account of the current status of the field and the major established and emerging lines of investigation in this vivid area of research.