Beam converter for enhancing brightness of polarized light sources

摘要

A polarization rotator has an input surface for receiving a first collimated beam at a first incident angle and for receiving a second collimated beam at a second incident angle. An output surface exits the polarization rotation of one of the first and second beams. A halfwave retarder extends between the input and output surfaces. The halfwave retarder has a crystallographic axis orientation rotated 45 degrees from the plane of the input surface and a thickness suitable for responding to only one of the first and second incident collimated beams. The halfwave retarder rotates one of the first and second collimated beams producing relative phase difference such that the polarization vector is rotated 90 degrees and the optical paths of the collimated beams are unchanged.