Brewster-angle 50%-50% beam splitter for p-polarized infrared light using a high-index quarter-wave layer deposited on a low-index prism

摘要

A quarter-wave layer (QWL) of high refractive index, which is deposited on a transparent prism of low refractive index, can be designed to split an incident p-polarized light beam at the Brewster angle (BA) of the air - substrate interface into p-polarized reflected and transmitted beams of equal intensity (50% each) that travel in orthogonal directions. For reflection of p-polarized light at the BA, the supported QWL functions as a free-standing (unsupported) pellicle. An exemplary design is presented that uses SixGe1-x QWL deposited on an IRTRAN1 prism for applications (such as Michelson and Mach - Zehnder interferometry) with a variable compositional fraction x in the 2 - 6 mu m mid-IR spectral range. (C) 2017 Optical Society of America