A Nomarski prism is a modification of the

Wollaston prism A Wollaston prism is an optical device, invented by William Hyde Wollaston, that manipulates polarized light. It separates light into two separate linearly polarized outgoing beams with orthogonal polarization. The two beams will be polarized a ...

that is used in

differential interference contrast microscopy Differential interference contrast (DIC) microscopy, also known as Nomarski interference contrast (NIC) or Nomarski microscopy, is an optical microscopy technique used to enhance the contrast in unstained, transparent samples. DIC works on the p ...

. It is named after its inventor, Polish and naturalized-French physicist

Georges Nomarski Georges (Jerzy) Nomarski (January 6, 1919 – 1997) was a Polish physicist and optics theoretician. Creator of differential interference contrast (DIC) microscopy, the method is widely used to study live biological specimens and unstained tissues a ...

. Like the Wollaston prism, the Nomarski prism consists of two birefringent crystal wedges (e.g.

quartz Quartz is a hard, crystalline mineral composed of silica ( silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical ...

or calcite) cemented together at the hypotenuse (e.g. with Canada balsam). One of the wedges is identical to a conventional Wollaston wedge and has the optical axis oriented parallel to the surface of the prism. The second wedge of the prism is modified by cutting the crystal so that the optical axis is oriented obliquely with respect to the flat surface of the prism. The Nomarski modification causes the light rays to come to a focal point outside the body of the prism, and allows greater flexibility so that when setting up the

microscope A microscope () is a laboratory instrument used to examine objects that are too small to be seen by the naked eye. Microscopy is the science of investigating small objects and structures using a microscope. Microscopic means being invisi ...

the prism can be actively focused.

References

*{{cite journal, last=Allen, first=RD, author2=David, GB , author3=Nomarski, G , title=The zeiss-Nomarski differential interference equipment for transmitted-light microscopy., journal=Zeitschrift für wissenschaftliche Mikroskopie und mikroskopische Technik, date=November 1969, volume=69, issue=4, pages=193–221, pmid=5361069, url=http://zeiss-campus.magnet.fsu.edu/referencelibrary/abstracts/dic05.html

External links

Nomarski Prism Action in Polarized LightWavefront Shear in Wollaston and Nomarski Prisms
Polarization (waves) Prisms (optics) Microscopy

See also

References

External links