Malus' law

[muh-loos; French ma-lys]
noun Optics.
  1. the law stating that the intensity of a beam of plane-polarized light after passing through a rotatable polarizer varies as the square of the cosine of the angle through which the polarizer is rotated from the position that gives maximum intensity.

Origin of Malus' law

named after E. L. Malus (1775–1812), French physicist
Also called law of Malus, Malus cosine-squared law [koh-sahyn skwaird] /ˈkoʊ saɪn ˌskwɛərd/.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018