The optical properties of a substance mainly refer to the various properties of the substance when it absorbs, reflects and refracts light, as well as the phenomenon of light interference and scattering caused by the substance. Optical properties are one of the most important and commonly used properties of materials. The performance evaluation of thin films, ceramics, glass, powder, polymers, intraocular crystals and even colloids is inseparable from the characterization of optical properties.