Field canalization using anisotropic 2D plasmonics

TL;DR

This paper introduces an integrated plasmonic canalization platform using anisotropic 2D materials like black phosphorus, enabling diffractionless light propagation with reduced loss-confinement tradeoff and dynamic reconfigurability.

Contribution

It demonstrates a novel method leveraging material absorption in anisotropic 2D materials to achieve long-range, subwavelength, near-diffractionless optical field propagation.

Findings

Achieved diffraction angle of 5.5 degrees

Propagation distance of 10 wavelengths

Supported deeply subwavelength, near-diffractionless fields

Abstract

Optical devices capable of suppressing diffraction nature of light are of great technological importance to many nanophotonic applications. One important technique to achieve diffractionless optics is to exploit field canalization effect. However, current technological platforms based on metamaterial structures typically suffer from strict loss-confinement tradeoff, or lack dynamic reconfigurability over device operations. Here we report an integrated canalization platform that can alleviate this performance tradeoff. It is found that by leveraging material absorption of anisotropic 2D materials, the dispersion of this class of materials can flatten without increasing propagation losses and compromising confinement. The realization of such plasmon canalization can be considered using black phosphorus (BP), where topological transition from elliptic to hyperbolic curves can be induced by dynamically leveraging material absorption of BP. At the transition point, BP film can support long range, deeply subwavelength, near-diffractionless field propagation, exhibiting diffraction angle of 5.5o, propagation distance of 10{\lambda}spp, and {\lambda}spp < {\lambda}0/300.