Dispersion prism is a glass block in shape of pentahedron with two non-active triangular surfaces and other 3 optically active surfaces. These prisms operate in transmitted light and most often are used to diverge light. The fundamental phenomenon taking place inside the prism is dispersion, that separates different wavelengths contained in the polychromatic light beam. Light leaving the prism is enclosed in an angle called angle of deflection. Its value is dependent on the material from which the prism was manufactured and the refracting angle of given prism. Most common dispersion prism is the equilateral prism with the refraction angle of 60 degrees. The bigger the difference of refraction indexes for different wavelengths, the more pronounced the spectral separation.