A retarder, or waveplate, is an optical device that resolves a light wave into two orthogonal linear polarization components and produces a phase shift between them. The resulting light wave generally is of a different polarization form. Ideally, retarders do not polarize, nor do they induce an intensity change in the light beam. They simply change its polarization form. Retarders are used in applications where control or analysis of polarization states is required. Our retarder products include innovative polymer and liquid crystal materials. Upon request, crystalline materials, such as quartz, magnesium fluoride, and sapphire, also are available.