Oprical Prism

An optical prism is a solid, transparent optic with flat surfaces which refract light. Light enters through one surface, and may be rotated, deviated, or dispersed before leaving through another surface. These surfaces are highly polished, and the angles between them, the number of surfaces, and the position of them determine the function of the prism.

They may be used to reflect light, to change the orientation of an image, to bend it within a system,or to break light up into it component wavelengths or polarizations. Isaac Newton used a simple prism to disperse a beam of white light into the full spectrum of component colors, proving that white light was in fact nothing but a combination of colors. This same dispersion technique is still used in spectrographs and refractometers. Optical prisms can also be used, in reverse, to combine optical beams into one.