The spin Hall effect of Light

When a beam propagates through inhomogeneous media,photons with opposite spin angular momenta will deviate from each other and assemble at the two sides of the beam section,leading to a spin-dependent splitting, and this phenomenon can be regarded as the spin Hall effect (SHE) of light. It is a direct optical analogy of the SHE in electronic systems where the spin electrons and electric potential are replaced by spin photons and the refractive index gradient, respectively.The SHE of light paves a new way to manipulate photons and may find important applications in nano-optics,quantum information, and semiconductor physics.Because of the close similarity and common topological roots of the effect in optics,condensed matter,and high-energy physics,the optical SHE provides indirect evidence of the intrinsic SHE in a diversity of physical systems.We present a simple introduction and overview of the latest research in this field.