{{no footnotes, date=October 2018
The extinction cross is an optical phenomenon that is seen when trying to extinguish a laser beam or non-planar white light using crossed
polarizer
A polarizer or polariser is an optical filter that lets light waves of a specific polarization (waves), polarization pass through while attenuation, blocking light waves of other polarizations. It can filter a beam of light of undefined or mixed ...
s. Ideally, crossed (90° rotated) polarizers block all light, because light that is polarized along the polarization axis of the first polarizer is perpendicular to the polarization axis of the second. When the beam is not perfectly collimated, however, a characteristic fringing pattern is produced.
See also
*
Polarization (waves)
, or , is a property of transverse waves which specifies the geometrical orientation of the oscillations. In a transverse wave, the direction of the oscillation is perpendicular to the direction of motion of the wave. One example of a polariz ...