An optical prism is a piece of glass or other transparent material that is cut at precise angles and planes. It can be used to analyze and reflect light. Ordinary triangular prisms can split white light into its component colors, which called spectrum. Each color or wavelength that makes up white light is bent or refracted into different quantity. Shorter wavelengths (which are toward the end of the purple in the spectrum) bend the most, while longer wavelengths (which are toward the end of the red in the spectrum) bend the least. This kind of prisms are used in certain spectroscopes, because it can analyze light and determine the identity and structure of materials that emit or absorb light.
Optical Prisms can reflect, disperse, or split light. They are usually made of glass. As long as the material is transparent and the wavelength can be designed, it also can be made into prism. The common materials include glass, plastic, and fluorite.Optical prisms can reverse the direction of light through internal reflection. They are widely bused to periscopes, binoculars and spotting scopes.