Patent ID: 6072628
Filing Date: 2000-06-06
Classification: G02B

Abstract:
Optical polarisation device for transforming an unpolarised incident beam of light into a linearly polarised beam of light, said optical polarisation device comprising:a polarisation separator reflecting one polarisation component of the light beam and transmitting the other polarisation component, said polarisation separator being constituted by a plane element,a reflection means receiving the component reflected by said polarisation separator, including means for rotating its polarisation plane through 90.degree. and returning it to the polarisation separator toward the beam of unpolarized light, said reflection means being positioned on the side of the polarization separator toward the beam of unpolarized light and being formed by a regular network of prisms composed of first and second sheets having complementary prismatic surfaces facing each other, the shape of each prism in cross-section corresponding to a right-angle triangle where the angle at the apex is equal to 90.degree., and one of the two other is approximately equal to the Brewster angle of the prisms, the longest side of each triangle opposite the hypotenuse being covered with a reflective layer,said means for rotating polarisation positioned between said reflective layers and said polarization separator.