A beam expander including a partial reflector, a reflective polarizer curved about two orthogonal axes and a quarter wave retarder disposed between the reflective polarizer and the partial reflector is described. The beam expander is adapted to receive an input light beam incident on the partial reflector and transmit an expanded output light beam. Illuminators and projection systems including the beam expander are described.

Optical systems including an image surface, a stop surface, a partial reflector disposed between the image surface and the stop surface, a reflective polarizer disposed between the stop surface and the partial reflector, and a quarter wave retarder disposed between the reflective polarizer and the partial reflector are described. The reflective polarizer is convex along two orthogonal axes. The reflective polarizer may be a thermoformed multilayer reflective polarizer.

A viewing devices includes an optical assembly comprising a display, an optical system forming of this display an image at infinity and a light guide for expanding a pupil in two spatial directions. The guide comprises three planar mirrors and two semi-reflective plates, the optical axis of the optical assembly being inclined with respect to the surface of the first planar mirror by an angle different from zero and strictly smaller than 90 degrees, the light beams output from the optical assembly propagating inside the light guide via successive reflections from the planar mirrors and the semi-reflective plates, the transmission of the light beams output from the optical assembly to outside of the light guide occurring via successive transmissions by the second semi-reflective plate.

Optical systems including an image surface and an exit surface are described. First second and third optical lenses, a partial reflector, a multilayer reflective polarizer and a retarder are disposed between the image surface and the exit surface. At least one location on at least one layer of the multilayer reflective polarizer is substantially uniaxially oriented. Each chief light ray that passes from the image surface to the exit surface is incident on the multilayer reflective polarizer with an angle of incidence less than about 30 degrees. The optical system may include a plurality of major surfaces disposed between the image surface and the exit surface where each major surface is convex toward the image surface and where at least six different major surfaces have six different convexities.

An optical system includes a reflective surface, a display adapted to emit image light toward the reflective surface, and a multilayer reflective polarizer disposed proximate the reflective surface. The multilayer reflective polarizer is curved about two orthogonal axes and includes at least one layer that is substantially optically uniaxial at at least one location. The image light is transmitted by the multilayer reflective polarizer after it is first reflected by the multilayer reflective polarizer. A head-mounted display includes a first optical system and a second optical system disposed proximate the first optical system.

Optical systems including an image surface, a stop surface, a partial reflector disposed between the image surface and the stop surface, a reflective polarizer disposed between the stop surface and the partial reflector, and a quarter wave retarder disposed between the reflective polarizer and the partial reflector are described. The reflective polarizer is convex along two orthogonal axes. The reflective polarizer may be a thermoformed multilayer reflective polarizer.

Optical systems including an image surface, a stop surface, a partial reflector disposed between the image surface and the stop surface, a reflective polarizer disposed between the stop surface and the partial reflector, and a quarter wave retarder disposed between the reflective polarizer and the partial reflector are described. The reflective polarizer is convex along two orthogonal axes. The reflective polarizer may be a thermoformed multilayer reflective polarizer.

A device utilized for spectrally combining multi lasers or laser emitters into a single high-power beam. Exemplary embodiments of the device consist of a monolithic structure, such as a hollow tube, wherein the input end cap comprises a transform optic and the output end cap comprises a transmission grating.

An optical stack includes first and second lenses, a partial reflector, a reflective polarizer, and a retarder. The reflective polarizer is curved about two orthogonal axes and includes at least one layer that is substantially optically uniaxial at at least one location. An optical system includes the optical stack disposed between an image surface and an exit surface. The optical system is configured such that substantially any chief ray transmitted from the image surface to the exit surface is first incident on the reflective polarizer at an angle of incidence less than 30 degrees.

A camera including an aperture, an image recording device, a reflective polarizer disposed between the aperture and the image recording device, a partial reflector disposed between the reflective polarizer and the image recording device, and a quarter wave retarder disposed between the reflective polarizer and the partial reflector. The reflective polarizer is curved about two orthogonal axes.