Nanocouplers for infrared and visible light

TL;DR

This paper reviews recent advances in nanocouplers for infrared and visible light, focusing on various physical principles and device designs that enable efficient coupling between micro- and nano-waveguides.

Contribution

It provides a comprehensive overview of different nanocoupling methods, including tapered waveguides, direct couplers, lenses, and scatterers, highlighting recent developments and common solutions.

Findings

Tapered waveguides enable efficient mode matching.

Plasmonic structures enhance coupling efficiency.

Multiple physical principles underpin nanocoupler designs.

Abstract

An efficient and compact coupler - a device that matches a micro-waveguide and a nano-waveguide - is an essential component for practical applications of nanophotonic systems. The number of coupling approaches has been rapidly increasing in the past ten years with the help of plasmonic structures and metamaterials. In this paper we overview recent as well as common solutions for nanocoupling. More specifically we consider the physical principles of operation of the devices based on a tapered waveguide section, a direct coupler, a lens and a scatterer and support them with a number of examples.