Circular polarization of vacuum ultraviolet light by piezobirefringence.

An instrument has been constructed that can produce any degree of elliptical polarization from linear to circular in the vacuum uv range 1050 A to 1450 A using a piezobirefringent retarder of LiF. The apparatus is conveniently described by the Mueller matrices. One of the piezobirefringence constants, P(11) - P(12), ranged from 4.0-10.0 x 10(-13) cm(2)/dyn for various samples of LiF, and the index of refraction at 1216 A was 1.79 +/- 0.14.