A beam splitter divides incident light into reflected and transmitted beams at a specified R/T ratio. For a lossless beam splitter, R + T = 1. When comparing beam splitters, always check whether the specified R/T ratio is for unpolarized light or for a specific. A beam splitter or beamsplitter is an optical device that splits a beam of light into a transmitted and a reflected beam. It is a crucial part of many optical experimental and measurement systems, such as interferometers, also finding widespread application in fibre optic telecommunications. a laser beam) into two (or sometimes more) beams, which may or may not have the same optical power (radiant flux). This is usually done by applying a thin-film coating on a glass substrate and angling the element relative to the incoming light.
