Nicol Prism (redirected from Nicol's prism)

Nicol prism (nĭk`əl), optical device invented (1828) by William Nicol of Edinburgh. It consists essentially of a crystal of calcite, or Iceland spar, that is cut at an angle into two equal pieces and joined together again with Canada balsam. An ordinary beam of light entering the crystal undergoes double refraction, i.e., is split into two parts, each of which is affected in a different way. One of these parts, the so-called ordinary ray, undergoes total reflection at the Canada-balsam joint and is turned off from its course to pass out at one side of the crystal. The other ray, the extraordinary ray, passes on through the crystal. By means of this device a beam of light can be polarized (see polarization of light) or a beam of polarized light can be subjected to analysis. The principle involved has been applied to the microscope in the illumination of the field.

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Nicol prism [′nik·əl ‚priz·əm]

(optics)

A device for producing plane-polarized light, consisting of two pieces of transparent calcite (a birefringent crystal) which together form a parallelogram and are cemented together with Canada balsam.

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Nicol Prism 

an optical device that transmits only linearly polarized light that has a certain direction of polarization. This prism was invented in 1828 by the Scottish physicist W. Nicol. Made of Iceland spar, or calcite (CaCO₃), it is one of the most widely used polarizing prisms.