Spin-Hall effect and circular birefringence of a uniaxial crystal plate

TL;DR

This paper demonstrates a novel spin-Hall effect of light in uniaxial crystal plates, revealing a circular birefringence that causes a transverse spin-dependent shift, with experimental validation using simple optical setups.

Contribution

It introduces and experimentally demonstrates a new circular birefringence effect in uniaxial crystals, linking it to the spin-Hall effect of light and expanding understanding of spin-orbit interactions.

Findings

Observation of transverse spin-dependent beam shift

Experimental validation using polarimetric techniques

Establishment of analogy with known beam shifts

Abstract

The linear birefringence of uniaxial crystal plates is known since the 17th century, and it is widely used in numerous optical setups and devices. Here we demonstrate, both theoretically and experimentally, a fine lateral circular birefringence of such crystal plates. This effect is a novel example of the spin-Hall effect of light, i.e., a transverse spin-dependent shift of the paraxial light beam transmitted through the plate. The well-known linear birefringence and the new circular birefringence form an interesting analogy with the Goos-H\"anchen and Imbert-Fedorov beam shifts that appear in the light reflection at a dielectric interface. We report the experimental observation of the effect in a remarkably simple system of a tilted half-wave plate and polarizers using polarimetric and quantum-weak-measurement techniques for the beam-shift measurements. In view of great recent interest in spin-orbit interaction phenomena, our results could find applications in modern polarization optics and nano-photonics.