The behavior of the beam splitter is core to the presence and reduction of noise due to vacuum fluctuations in LIGO, which injects a squeezed vacuum state into the empty input port of the beamsplitter to reduce coupling of quantum noise into the interferometer. A beam splitter (or beamsplitter, power splitter) is an optical device which can split an incident light beam (e. a laser beam) into two (or sometimes more) beams, which may or may not have the same optical power (radiant flux). Different types of beam splitters exist, as described in the. Aluminium-coated beam splitter. Another design is the use of a half-silvered mirror. Therefore, they play an important role in fields such as interferometry, quantum optics experiments, laser processing, and imaging systems.