Laurent half-shade plate

Laurent half-shade plate

[lȯ′rän ′haf ‚shād ‚plāt]
(optics)
A device used to determine the direction of polarization of plane polarized light; it consists of a quartz plate of special thickness that covers half of the plane polarized beam, followed by a plane polarization analyzer.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.