The basic principle is straightforward: light hits a specially coated surface, and that coating is engineered to reflect some of the light while letting the rest pass through. By adjusting the coating's material and thickness, manufacturers control exactly how much light goes each. 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. These tools can split both laser and regular light. a laser beam) into two (or sometimes more) beams, which may or may not have the same optical power (radiant flux).
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