Malus’ law

Malus’ law [muh-loos; French ma-lys] Word Origin 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 physicistAlso called law of Malus, Malus cosine-squared law [koh-sahyn skwaird] /ˈkoʊ saɪn ˌskwɛərd/.