The beam splitters coating is a thin film that divides a light beam into two parts according to a certain light intensity ratio, so that one part of the beam passes through the lens and reflects the remaining light. If this film only considers a certain wavelength, it is called a monochromatic splitter coating; If the splitter coating considers a spectral range, it is called broadband splitter coating; A broadband splitter coating used for visible light, also known as a neutral splitter coating.