Abstract: When a spatially limited light beam is reflected and refracted at an interface,its two spin components or the left- and right-circularly polarized beams acquire opposite transverse displacements perpendicular to the plane of incidence.Recently,this novel spin Hall effect of light has attracted much attention.We review the research in this field,focusing especially on the measurement of the separation on the nanometer scale.We have also observed the spin separation of light in the plane of incidence when a linearly polarized beam is reflected and refracted at a planar dielectric interface.The experimental results are in excellent agreement with the theoretical analysis.