Infrared Brewster-angle polarizing beam splitter using a high-index prism with a small wedge angle

Specular reflection at the Brewster angle by a planar surface of a high-refractive-index transparent substrate is an effective means of generating linearly polarized light in the infrared. However, in such a reflection linear polarizer, the refracted light beam is usually dumped. In this paper we describe a polarizing beam splitter (PBS) that uses a high-index prism with a small wedge angle to generate two orthogonally p and s linearly polarized beams that travel in orthogonal directions. A single-layer antireflection coating (ARC) at the exit face of the prism can be embedded with aligned Ag nano needles to suppress the transmission of the small, residual, s-polarized refracted component. An example of such PBS that uses a PbTe prism with ZnSe ARC in the mid-infrared is presented.