half-wave plate

[haf-weyv, hahf-]

noun Optics.

a crystal thin enough to cause a phase difference of 180° between the ordinary and extraordinary rays of polarized light, thereby changing the direction of the plane of polarization.

Compare quarter-wave plate.

Origin of half-wave plate

First recorded in 1900–05

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018