quarter-wave plate

[ kwawr-ter-weyv ]
/ ˈkwɔr tərˌweɪv /

noun Optics.

a crystal thin enough to cause a phase difference of 90° between the ordinary and extraordinary rays of polarized light, thereby converting circularly polarized light into plane polarized light.

Origin of quarter-wave plate

First recorded in 1880–85
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019