Abstract: An optical interferometer includes a monolithic optical element.

Abstract: A beam distribution apparatus includes a stack of parallelogram prisms and beam-splitting coatings each located between opposing parallel faces of adjacent parallelogram prisms. The stack is mounted on an entrance face of a triangular prism. The triangular prism includes the entrance face, a reflective face, and an exit face. The reflective face has optical surfaces for shaping output beams from the stack and reflecting the output beams through the exit face. A beam distribution apparatus includes a stack of parallelogram prisms and beam-splitting coatings each located between opposing parallel faces of adjacent parallelogram prisms in the stack. The beam-splitting coatings transmit light of a first polarization and reflect a portion of light of a second polarization. The apparatus further includes retardation plates each mounted on a face of a parallelogram prism adjacent to a beam-splitting coating, and corrective reflective optics for shaping output beams each mounted on a retardation plate.

Abstract: A phase-compensating cube corner retroreflector includes three rear reflecting surfaces. All three rear reflecting surfaces can be coated with a phase-compensating film stack that induces 2n? phase difference when handling polarized light. So coated, the phase-compensating cube corner preserves the polarization orientation and ellipticity of the incident light. Such a phase-compensating cube corner can be used to improve the accuracy of distance-measuring interferometers. The cube corner directs light to and from other optical elements, including a polarizing beam-splitters, mirrors, and quarter-wave plates.

Abstract: An interferometer system includes a rhomboid assembly having a first optical stack and a second optical stack mounted on the first stack. The first stack includes a first prism having an angled face mounted to an angled face of a second prism. The interface between these angled faces includes a first polarizing beam-splitter. The second stack includes a third prism having an angled face mounted to an angled face of the fourth prism. The interface between these angled faces includes a second polarizing beam-splitter. First, second, third, and fourth wave plate elements are located in beam paths between the rhomboid assembly and at least one of a measurement optic and a reference optic. A redirecting optic is located at least adjacent to the vertical faces of the first and the third prisms.

Abstract: An interferometer system includes a plane mirror interferometer, a turning mirror, a retardation plate assembly having a retardation plate that can be adjusted and then fixed, and a retroreflector. A light beam travels in a path comprising the plane mirror interferometer, the turning mirror, the retardation plate assembly, and the retroreflector. The retardation plate assembly may include a plurality of bearings, a ring riding on the bearings, the retardation plate mounted to the ring, and a plunger pushing the ring against the bearings. The retardation plate may be fixed by adhesive after determining an orientation that produces little polarization leakage in the system.

Abstract: Measurement systems that separate polarization components can use retroreflectors to preserve or transform polarization and avoid unwanted mixing of the polarization components. A suitable retroreflector can include a coated cube corner reflector with retardation plates having a slow axis set at a non-zero angle away from 45° with the directions of linearly polarized component beam. The non-zero angle can be set in situ to minimize polarization mixing in a measurement system. Alternatively, a cube corner reflector with one or more polarization manipulating elements controls the polarization of a reflected beam to preserve or transform the polarization of an incident beam.

Abstract: A phase-compensating cube corner retroreflector includes three rear reflecting surfaces. The first and the third rear reflecting surfaces can be coated with a phase-compensating film stack that induces 2n? phase difference upon reflection, where n is an integer including 0. Alternatively, all three rear reflecting surfaces can be coated with a phase-compensating film stack that induces n? phase difference when handling linearly polarized light, or 2n? phase difference when handling linearly or circularly polarized light. So coated, the phase-compensating cube corner preserves the polarization orientation and ellipticity of the incident light. Such a phase-compensating cube corner can be used to improve the accuracy of distance-measuring interferometers. The cube corner directs light to and from other optical elements, including a polarizing beam-splitters, mirrors, and quarter-wave plates.