Calcite, Nicol prism

When light is passed through a polarizer such as a calcite Nicol prism, the electric vector is parallel to the plane of polarization. The electric vector transforms in different ways when the polarized light is transmitted through a single crystal of a mineral, depending on its crystal symmetry. 

Crossed Nicol prisms An arrangement of two materials (calcite polarizing prisms or Polaroid discs) such that the first, the polarizer, transmits plane-polarized light that passes through the second, the analyzer, only if oriented in specific ways. 

Nicol prism n A polarizing element made of two pieces of calcite specially cut, ground, polished, and cemented. A transmitted beam splits into two polarized components, one of which is refracted into and absorbed by the asphalt mount. The remaining polarized beam is transmitted. 

A prism made of two pieces of calcite cut in a certain way and cemented together has the property of permitting only one beam to pass through the other is reflected to the side and absorbed in the darkened side of the prism. Such a prism (called a Nicol prism) can be used to form a beam of... 

Subsequently, in 1828, Nicol (W. Nicol 1770-1851, Edinburgh) constructed an optical device (the Nicol prism) made from calcite, cut so as to remove one of the two refracted rays by total reflection. Therefore, only passage of a single beam of plane-polarized light (i.e., light confined to one plane) is allowed through a Nicol prism. 

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