They are less susceptible to scratching and offer more resistance to damage from high-power laser radiation. (27) The most likely. 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. Beamsplitters are often classified according to their construction: cube or plate. For example, beam splitters with metallic coatings exhibit relatively high losses, whereas devices with dichroic coatings may have negligible losses: The total output power nearly equals the input power.