Interference Technique for Experimental Observation of the Spin Flow

Abstract

Study of the internal energy flows is a rapidly developing branch of physical optics (see, e.g., Refs. [1–8]). The internal flows (optical currents) not only constitute an “energy skeleton” of a light field, which reflects important physical characteristics of its spatial structure. They have proven to be valuable instruments for investigation of fundamental dynamical and geometrical aspects of the light fields’ evolution and transformations [1–5], provide a natural language for explaining the special features of singular fields [1, 2, 4-6], fields with angular momentum [3,6-8] and for interpreting the effects of spin-orbit interaction of light [5]. As physically meaningful and universal parameters of light fields, they permit to disclose physical mechanisms of the beam transformation upon free and restricted propagation and offer attractive possibilities for characterization of arbitrary light fields [5].