Patent ID: 6040942
Filing Date: 2000-03-21
Classification: G02B

Abstract:
A polarization separator/combiner for separating a light beam comprising first and second components of orthogonal polarization into separate first and second light beams having substantially homogeneous and orthogonal polarization, or for combining separate first and second light beams having substantially homogeneous and orthogonal polarization into a single light beam comprising orthogonally polarized components, the separator/combiner comprising:a first plate and a second plate, each plate comprising:a first surface and a second surface, the first surface and the second surface being parallel, and spaced apart by the thickness of a transparent body therebetween,the first surface having a coating applied thereto, such that the first surface forms a planar polarizing interface,the coating being selected such that when a light beam having a first component having a first polarization and a second component having a second polarization orthogonal to the polarization of the first component strikes the first surface at a predetermined angle, the first component of light beam is substantially reflected by the coating, and the second component of the light beam is substantially transmitted through the coating;the second surface of the plate forming a planar reflective interface;such that the second component of light passes through the polarizing interface and through the transparent body of the plate, reflects off the reflective interface, and passes again through the polarzing interface, emerging parallel to the first light component,the first plate being mounted parallel to the second plate and spaced apart therefrom, such that the first component and the second component pass from the first plate to the second plate without any optical components in the optical path between the first plate and the second plate which would effect the polarization of either the first component or the second component,such that one of the first component and second component is reflected from the polarizing interface of the second plate to become parallel to the light beam, and the other component is transmitted through the polarizing interface of the second plate, reflects from the reflective interface of the second plate, and emerges through the polarization interface of the second plate, parallel to the light beam.