A beam splitter (or beamsplitter, power splitter) is an optical device which can split an incident light beam (e. It is a crucial part of many optical experimental and measurement systems, such as interferometers, also finding widespread application in fibre optic telecommunications. They can also be used in reverse to combine two or more separate beams into a single one. a laser beam) into two (or sometimes more) beams, which may or may not have the same optical power (radiant flux). These plates are typically made of high-quality glass coated with a thin, anti-reflective film. The coating helps to minimize issues with annoying back reflections, such. A cube beamsplitter is composed of a prism with a partially-reflecting coating bonded to a second prism, and typically divides a beam based on power or polarization. Antireflection coatings on the entry and exit faces of the cube minimize loss and reduce ghost reflections (though they are still.
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