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

Abstract

The linear birefringence of uniaxial crystal plates has been known since the 17th century, and it is widely used in numerous optical setups and devices. Here we demonstrate, both theoretically and experimentally, the fine lateral circular birefringence of such crystal plates. We show that 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–Hänchen and Imbert–Fedorov beam shifts that appear in the light reflection at a dielectric interface. We report 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 beam-shift measurements. In view of much recent interest in spin–orbit interaction phenomena, our results could find applications in modern polarization optics and nanophotonics.