Photonic spin Hall effect in hyperbolic metamaterials at visible

TL;DR

This paper demonstrates the first experimental observation of the photonic spin Hall effect in hyperbolic metamaterials at visible wavelengths, showing large, angle-sensitive beam shifts that could enable miniaturized optical devices.

Contribution

First experimental demonstration of the photonic spin Hall effect in multilayer hyperbolic metamaterials at visible wavelengths with significant beam shifts and high angular sensitivity.

Findings

Observed a 165 μm beam shift at 520 nm wavelength.

Beam shift is highly sensitive to incident angle, changing by 270 μm per 0.057°.

Metamaterials exhibit extremely large anisotropy enabling enhanced effects.

Abstract

Photonic spin Hall effect in transmission is a transverse beam shift of the out-coming beam depending on polarization of the in-coming beam. The effect can be significantly enhanced by materials with high anisotropy. We report the first experimental demonstration of the photonic spin Hall effect in a multilayer hyperbolic metamaterial at visible wavelengths (wavelengths of 520 nm and 633 nm). The metamaterial is composed of alternating layers of gold and alumina with deeply-subwavelength thicknesses, exhibiting extremely large anisotropy. The angle resolved polarimetric measurements showed the shift of 165 $\mu m$ for the metamaterial of 176 nm in thickness. Additionally the transverse beam shift is extremely sensitive to the variations of the incident angle changing theoretically by 270 $\mu m$ with one milli-radian ($0.057^\circ$). These features can lead to minituarized spin Hall switches and filters with high angular resolution.