- Glan-Taylor prism
A Glan-Taylor prism is a type of prism which is used as a
polarizer or polarizingbeam splitter .cite book |last=Bennett |first=Jean M . |editor=Bass, Michael, Ed. |title=Handbook of Optics Volume II |edition=2nd ed. |year=1995 |publisher=McGraw-Hill |isbn=0-07-047974-7 |pages=pp. 3.13–3.14 |chapter=Polarizers ] It is one of the most common types of modern polarizing prism. It was first described by Archard and Taylor in 1948. [cite journal | first= J.F. |last=Archard |coauthors=Taylor, A.M. | title=Improved Glan-Foucault prism | journal=J. Sci. Instrum. | year=1948 | volume=25 | issue= | pages= 407–409 | url=http://dx.doi.org/10.1088/0950-7671/25/12/304 ]The prism is made of two right-angled prisms of
calcite (or sometimes other birefringent materials) which are separated on their long faces with an air gap. The optical axes of the calcite crystals are aligned parallel to the plane of reflection.Total internal reflection of "s"-polarized light at the air-gap ensures that only "p"-polarized light is transmitted by the device. Because the angle of incidence at the gap can be reasonably close toBrewster's angle , unwanted reflection of "p" polarized light is reduced, giving the Glan-Taylor prism better transmission than the Glan-Foucault design.cite journal | author=J-Y Fan "et al." | title=A study on transmitted intensity of disturbance for air-spaced Glan-type polarizing prisms | journal=Optics Communications | year=2003 | volume=223 | issue=1-3 | pages= 11–16 | doi=10.1016/S0030-4018(03)01618-3 ] Note that while the transmitted beam is 100% polarized, the reflected beam is not. The sides of the crystal can be polished to allow the reflected beam to exit, or can be blackened to absorb it. The latter reduces unwantedFresnel reflection of the rejected beam.A variant of the design exists called a Glan-laser prism. This is a Glan-Taylor prism with a steeper angle for the cut in the prism, which decreases reflection loss at the expense of reduced angular field of view. These polarizers are also typically designed to tolerate very high beam intensities, such those produced by a
laser . The differences may include using calcite which is selected for low scattering loss, improved polish quality on the faces and especially on the sides of the crystal, and betterantireflection coating s. Prisms withirradiance damage thresholds greater than 1 GW/cm2 are commercially available.ee also
*
Glan-Foucault prism
*Glan-Thompson prism References
*
Wikimedia Foundation. 2010.
