Photonic spin Hall effect in metasurfaces with rotational symmetry-breaking

TL;DR

This paper demonstrates the observation and control of the photonic spin Hall effect in dielectric metasurfaces with broken rotational symmetry, highlighting the role of space-variant Pancharatnam-Berry phase and the impact of metasurface rotation.

Contribution

It introduces a method to observe and enhance the photonic SHE in metasurfaces by breaking rotational symmetry and adjusting the metasurface rotation rate.

Findings

Spin-dependent splitting observed as angular splitting in real space

Breaking rotational symmetry enables observable spin-dependent shift

Increasing metasurface rotation enhances the spin-dependent shift

Abstract

Observation of photonic spin Hall effect (SHE) in dielectric-based metasurfaces with rotational symmetry breaking is presented. We find that the spin-dependent splitting is a unique angular splitting in the real position space, and is attributed to the space-variant Pancharatnam-Berry phase (PB). Breaking the rotational symmetry of the PB phase by misalignment of the central axes of the incident beam and the metasurface, the spin-dependent shift is observable. We show that the spin-dependent shift can be enhanced by increasing the rotation rate of the metasurface, so the metasurface provides a great flexibility in the manipulation of photonic SHE.