Abstract: A folded light path illuminator is provided. The illuminator may include a polarizing beam splitter having an input face, an output face and an imager face, a light source disposed adjacent the input face and defining an input active area on the input face, and an image forming device disposed adjacent the imager face for receiving light emitted from the light source and emitting a patterned light, which may be a converging patterned light. The image forming device may have a largest image area which defines an output active area on the output face. One or both of the input active area and the output active area may be less than about half the largest image area. The polarizing beam splitter may include first and second prisms and the volume of the first prism may be no greater than half the volume of the second prism.

Abstract: An optical stack including a first reflective polarizer adhered to a second reflective polarizer is described. For normally incident light and each wavelength in a same predetermined wavelength range, each reflective polarizer transmits at least 80% of light polarized along a pass axis of the reflective polarizer and reflects at least 90% of light polarized along an orthogonal block axis of the reflective polarizer. Each reflective polarizer includes a plurality of polymeric interference layers reflecting and transmitting light primarily by optical interference in the predetermined wavelength range. A separation between the two polymeric interference layers in the plurality of polymeric interference layers farthest from each other are d1 and d2 for the respective first and second reflective polarizers, d1 is at least 20% less than d2. Polarizing beam splitters including the optical stack and optical systems including the polarizing beam splitter are described.

Abstract: A reflective polarizing imaging lens includes at least one optical film having an active area that is curved in two orthogonal directions. Edges of the optical film are arranged to form seams between segments of the optical film in the active area of the reflective polarizing imaging lens.

Abstract: An optical system including one or more optical lenses, at least one retarder layer, a reflective polarizer, and a partial reflector is provided. The at least one retarder layer may include first and second retarder layers having different wavelength dispersion curves. The at least one retarder layer may include a first retarder layer having a non-uniform fast axis orientation and/or a non-uniform retardance.

Abstract: 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.

Abstract: Optical films and polarizing beam splitters including the optical films are described. In some cases, the optical film includes a first optical stack disposed on, and spaced apart by one or more spacer layers from, a second optical stack, each optical stack comprising a plurality of polymeric interference layers reflecting and transmitting light primarily by optical interference in a same predetermined wavelength range. Each optical stack has interference layers closer to the one or more spacer layers that reflect longer wavelengths and interference layers farther from the one or more spacer layers that reflect shorter wavelengths.

Abstract: An optical system including a first optical element having a curved first major surface and an optical stack bonded and conforming to the curved first major surface of the first optical element is described. The optical stack includes a reflective polarizer substantially transmitting light having a first polarization state and substantially reflecting light having an orthogonal second polarization state and a non-adhesive flexible optical layer bonded to the reflective polarizer and comprising substantially parallel opposing first and second major surfaces. At least one location on the non-adhesive flexible optical layer has an optical retardance of less than about 100 nm or greater than about 200 nm at a wavelength of about 550 nm.

Abstract: An optical element includes an optical surface configured to receive light at a predetermined wavelength in a range from about 400 nm to about 1000 nm. The optical surface is defined by a vertical axis and a horizontal axis defining four Cartesian quadrants sequentially numbered in a counter-clockwise direction. A first longitudinal section of the optical surface is centered on the vertical axis and a second longitudinal section of the optical surface is centered on the horizontal axis. The first and second longitudinal section each extend across opposite edges of the optical surface and have a same substantially uniform retardance for substantially normally incident light. The optical element includes four discrete retarder sections. Each retarder section is disposed on a respective Cartesian quadrant of the optical surface and has a retardance difference from the substantially uniform retardance of the optical surface that is greater than zero.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Shaped optical films and methods of shaping optical films are described. The method includes securing at least portions of a perimeter of the optical film in a first plane so that the secured portions do not move relative to one another; and stretching the optical film by displacing a portion of the optical film along at least a first direction perpendicular to the first plane such that one of a radial and circumferential stretching of the optical film is substantially constant from a center to the perimeter of the optical film, and the other one of the radial and circumferential stretching of the optical film substantially changes from the center to the perimeter of the optical film. The optical film is a reflective polarizer including a plurality of alternating polymeric layers.

Abstract: 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.

Abstract: An optical lens including first and second polarizers, a partial reflector disposed between the first and second polarizers, a first phase retarder disposed between the first polarizer and the partial reflector, and a second phase retarder disposed between the partial reflector and the second polarizer is described. The optical lens is a single piece configured for use in an eyewear. Eyewear including at least one of the optical lenses is also described.

Abstract: 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.

Abstract: 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.

Abstract: Light emitting systems and optical systems including a light emitting system and a lens system are described. The light emitting system includes a pixelated light source having a plurality of discrete spaced apart pixels, and includes a plurality of light redirecting elements, each light redirecting element corresponding to a different pixel in the plurality of pixels. The light redirecting elements may be adapted to alter one or both of a central ray direction and a divergence angle of light received from the corresponding pixel. A lens system disposed to receive light from the light emitting system may include a reflective polarizer and a partial reflector.

Abstract: 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.

Abstract: An optical system including at least a first lens, a partial reflector and a reflective polarizer is described. The optical system has an optical axis such that a light ray propagating along the optical axis passes through the first lens the partial reflector and the reflective polarizer without being substantially refracted. At least one major surface of the optical system is rotationally asymmetric about the optical axis. A major surface of the optical system may have a first portion defined by a first equation and a second portion adjacent the first portion defined by a different equation. The first lens may have a contoured edge adapted to be placed adjacent an eye of a viewer and substantially conform to the viewer's face.

Abstract: An optical system for displaying an object to a viewer is described. The optical system includes an integral first optical assembly, an integral second optical assembly, and an integral third optical assembly disposed between the integral first and second optical assemblies. The integral first optical assembly has a first focal length and includes one or more first optical lenses, and a reflective polarizer. The integral second optical assembly has a second focal length and includes one or more second optical lenses, and a partial reflector having an average optical reflectance of at least 30% for a desired plurality of wavelengths. The integral third optical assembly has a third focal length and includes a curved first phase retarder. The third focal length is greater than a smaller of the first and second focal lengths.