The 2 forms of beamsplitters are cube and plate type. 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. A beamsplitter is an optical device capable of splitting an incident light beam into two. Introduction A beam splitter divides incident light into reflected and transmitted beams at a specified R/T. A beam splitter, or beamsplitter, is an optical component used to divide incident light into two separate beams based on wavelength, intensity, or polarization.