What is Dichroism?
Dichroism has two related but distinct meanings in optics. A dichroic material is either one which causes visible light to be split up into distinct beams of different wavelengths (colors) (not to be confused with dispersion), or one in which light rays having different polarizations are absorbed by different amounts. The original meaning of dichroic, from the Greek dikhroos, two-colored, refers to any optical device which can split a beam of light into two beams with differing wavelengths. Such devices include mirrors and filters, usually treated with optical coatings, which are designed to reflect light over a certain range of wavelengths, and transmit light which is outside that range. An example is the dichroic prism, used in some camcorders, which uses several coatings to split light into red, green and blue components for recording on separate CCD arrays. This kind of dichroic device does not usually depend on the polarization of the light. The term dichromatic is also used in th
