High efficiency homogeneous polarization converter

Abstract

A polarization converter for polarizing a light beam by converting all light waves to the same orientation comprises 1) a first beam dividing matrix of refractory material for dividing a single, large light beam into smaller sub-beam 2) a second beam focusing matrix for polarizing select portions of the sub-beams, and 3) a series of narrow and shallow polarizing cells. The second beam focusing matrix further comprises a plurality of concave lenses for redirecting each sub-beam and quarter wave retarders disposed in alignment with, and adjacent to, the reflective side of an equal plurality of mirror segments. The polarizing cells include either a first beamsplitter or a second beamsplitter, where the first beamsplitters and second beamsplitters are disposed in opposing diagonal fashion and in an alternating manner. Lightwaves of a selected polarization pass directly through the first beamsplitter and out of the polarizing cell, while all other lightwaves are horizontally reflected by the first beamsplitter and directed onto the second beamsplitter where they are redirected toward the quarter wave retarder. The reflected light passes through the quarter wave retarder, reflects off of the mirror and again passes through the quarter wave retarder. The wavelength of the light is retarded ninety degrees as a result of the two passes through the quarter-wave retarder, thus re-orienting the light to the selected orientation. The re-oriented p-waves pass through the second beamsplitter and exit the polarizing cell, join the original p-waves exiting the polarizing cells, and form a beam of polarized light.