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: Optical systems including a partial reflector, a reflective polarizer, and a retarder disposed between the partial reflector and the reflective polarizer are described. 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. The optical system is adapted to provide an adjustable focus.

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: An optical system and a magnifying device including the optical system are described. The optical system includes an exit pupil, a reflective polarizer proximate the exit pupil, a partial reflector disposed adjacent the reflective polarizer opposite the exit pupil, and a quarter wave retarder disposed between the reflective polarizer and the partial reflector. The reflective polarizer is curved about two orthogonal axes and the partial reflector is spaced apart from the reflective polarizer.

Abstract: Integral optical stacks and optical systems including the integral optical stack are described. The integral optical stack may include first and second lenses, a partial reflector, a reflective polarizer curved about two orthogonal axes, and a quarter wave retarder. The reflective polarizer is curved about two orthogonal axes and includes at least one layer that is substantially optically biaxial at at least one first location on the at least one layer away from an optical axis of the optical stack and substantially optically uniaxial at at least one second location away from the optical axis.

Abstract: Optical systems including a partial reflector, a reflective polarizer, and a quarter wave retarder disposed between the partial reflector and the reflective polarizer are described. The reflective polarizer is curved about two orthogonal axes and has at least one location having a radial distance r1 from an optical axis passing through an apex of the reflective polarizer and a displacement s1 from a plane perpendicular to the optical axis at an apex of the reflective polarizer, where s1/r1 is at least 0.1. The optical system is adapted to provide an adjustable dioptric correction.

Abstract: A head-mounted display including a first optical system is described. The first optical system includes a partial reflector and a multilayer reflective polarizer disposed adjacent to and spaced apart from the partial reflector. The multilayer reflective polarizer is curved about orthogonal first and second axes and includes at least one layer that is substantially optically uniaxial at at least one location. Each chief ray that passes through the first optical system is first incident on the multilayer reflective polarizer at an angle of incidence less than 30 degrees.

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: A head-mounted display including a first optical system is described. The first optical system includes a partial reflector and a multilayer reflective polarizer disposed adjacent to and spaced apart from the partial reflector. The multilayer reflective polarizer is curved about orthogonal first and second axes and includes at least one layer that is substantially optically uniaxial at at least one location. Each chief ray that passes through the first optical system is first incident on the multilayer reflective polarizer at an angle of incidence less than 30 degrees.

Abstract: Methods of making optical films and optical stacks are described. A method of making an optical lens molded to a first curved optical film includes providing a first optical film including alternating first and second polymeric layers; providing a thermoform tool having a curved surface; heating and conforming the first optical film to the curved surface to form a first curved optical film; and molding an optical lens onto the first curved optical film.

Abstract: Optical systems including an image surface and a stop surface are described. First second and third optical lenses, a partial reflector, a multilayer reflective polarizer and a quarter wave retarder are disposed between the image surface and the stop surface. A plurality of major surfaces are disposed between the image surface and the stop surface with each major surface convex toward the image surface along orthogonal first and second axes. At least six different major surfaces have six different convexities.

Abstract: Integral optical stacks and optical systems including the integral optical stack are described. The integral optical stack may include first and second lenses, a partial reflector, a reflective polarizer curved about two orthogonal axes, and a quarter wave retarder. The reflective polarizer is curved about two orthogonal axes and includes at least one layer that is substantially optically biaxial at at least one first location on the at least one layer away from an optical axis of the optical stack and substantially optically uniaxial at at least one second location away from the optical axis.

Abstract: Optical systems including a partial reflector, a reflective polarizer, and a quarter wave retarder disposed between the partial reflector and the reflective polarizer are described. The reflective polarizer is curved about two orthogonal axes and has at least one location having a radial distance r1 from an optical axis passing through an apex of the reflective polarizer and a displacement s1 from a plane perpendicular to the optical axis at an apex of the reflective polarizer, where s1/r1 is at least 0.1. The optical system is adapted to provide an adjustable dioptric correction.

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: A multilayer reflective polarizer convex along orthogonal first and second axes orthogonal to an optical axis passing thorough an apex of the multilayer reflective polarizer is described. The multilayer reflective polarizer has at least one first location having a radial distance r1 from the optical axis and a displacement s1 from a plane perpendicular to the optical axis at the apex, where s1/r1 is in a range of about 0.2 to about 0.8. The multilayer reflective polarizer may have at least one inner layer substantially optically uniaxial at at least one first location away from the apex. For an area of the reflective polarizer defined by s1 and r1, a maximum variation of a transmission axis of the reflective polarizer may be less than about 2 degrees.

Abstract: A head-mounted display including a first optical system is provided. The first optical system includes an image surface, a stop surface, a first optical stack disposed between the image surface and the stop surface and a second optical stack disposed between the first optical stack and the stop surface. The first optical stack includes a first optical lens and a partial reflector. The second optical stack includes a second optical lens and a curved multilayer reflective polarizer. A quarter wave retarder is disposed between the multilayer reflective polarizer and the partial reflector. The multilayer reflective polarizer and the partial reflector may be convex toward the image surface along orthogonal first and second axes.

Abstract: Methods of making optical films and optical stacks are described. A method of making an optical stack includes providing a thermoform tool centered on a tool axis and having an external surface rotationally asymmetric about the tool axis; heating an optical film resulting in a softened optical film; conforming the softened optical film to the external surface while stretching the softened film along at least orthogonal first and second directions away from the tool axis resulting in a conformed optical film rotationally asymmetric about an optical axis of the conformed film where the optical axis coincident with the tool axis; cooling the conformed optical film resulting in a symmetric optical film rotationally symmetric about the optical axis; and molding an optical lens on the symmetric optical film resulting in the optical stack.

Abstract: Integral optical stacks and optical systems including the integral optical stack are described. The integral optical stack may include first and second lenses, a partial reflector, a reflective polarizer curved about two orthogonal axes, and a quarter wave retarder. The reflective polarizer is curved about two orthogonal axes and includes at least one layer that is substantially optically biaxial at at least one first location on the at least one layer away from an optical axis of the optical stack and substantially optically uniaxial at at least one second location away from the optical axis.

Abstract: A multilayer reflective polarizer substantially rotationally symmetric about an optical axis passing thorough an apex of the multilayer reflective polarizer and convex along orthogonal first and second axes orthogonal to the optical axis is described. The multilayer reflective polarizer has at least one first location having a radial distance r1 from the optical axis and a displacement s1 from a plane perpendicular to the optical axis at the apex, where s1/r1 is at least 0.1. The multilayer reflective polarizer may have at least one inner layer substantially optically uniaxial at at least one first location away from the apex. For an area of the reflective polarizer defined by s1 and r1, a maximum variation of a transmission axis of the reflective polarizer may be less than about 2 degrees.

Abstract: Optical systems including first and second optical stacks and adapted to provide an adjustable dioptric correction are described. The first optical stack includes a first optical lens and a partial reflector. The second optical stack is convex along orthogonal first and second axes and includes a second optical lens and a reflective polarizer. The reflective polarizer has at least one first location having a radial distance r1 from an optical axis of the second optical stack and a displacement s1 from a plane perpendicular to the optical axis at an apex of the reflective polarizer, where s1/r1 is at least 0.1. A quarter wave retarder is disposed between the second optical stack and the first optical stack.