Abstract: A vehicle may have a head-up display that produces a display output allowing a viewer in the vehicle to observe two-dimensional or three-dimensional content. The head-up display may include a display unit that produces the display output and an optical combiner on a vehicle window that directs the display output towards the viewer. The optical combiner may be a holographic or diffractive optical element or may be an array of angled reflectors such as micromirrors embedded in an index-matching material. Optical combiners formed from holographic elements may be configured to reflect light at an angle of reflection that is different than the angle of incidence, thereby allowing light to reach a viewer's eyes even when the head-up display reflects light off of a side window on a vehicle door. A holographic optical element may include volume holographic media such as photopolymers or holographic polymer dispersed liquid crystal.

Abstract: A head-mounted display may include a display system and an optical system in a housing. The display system may have a pixel array that produces light associated with images. The display system may also have a linear polarizer through which light from the pixel array passes and a quarter wave plate through which the light passes after passing through the quarter wave plate. The optical system may be a catadioptric optical system having one or more lens elements. The lens elements may include a plano-convex lens and a plano-concave lens. A partially reflective mirror may be formed on a convex surface of the plano-convex lens. A reflective polarizer may be formed on the planar surface of the plano-convex lens or the concave surface of the plano-concave lens. An additional quarter wave plate may be located between the reflective polarizer and the partially reflective mirror.

Abstract: A vehicle may have optical structures such as windows and mirrors that have the potential to allow glare from external objects to shine into the eyes of a driver or other vehicle occupant. A control circuit may gather information on where the eyes of the driver are located using a camera mounted in the vehicle and may gather information on where the sun or other source of glare are located outside of the vehicle. Based on this information, the control circuit may direct a light modulator on a window or mirror to selectively darken an area that prevents the glare from reaching the eyes of the driver. The light modulator may have a photochromic layer that is adjusted by shining light onto the photochromic layer, may be a liquid crystal modulator, an electrochromic modulator, or other light modulator layer.

Abstract: A head-mounted display may include a display system and an optical system in a housing. The display system may have a pixel array that produces light associated with images. The display system may also have a linear polarizer through which light from the pixel array passes and a quarter wave plate through which the light passes after passing through the quarter wave plate. The optical system may be a catadioptric optical system having one or more lens elements. The lens elements may include a plano-convex lens and a plano-concave lens. A partially reflective mirror may be formed on a convex surface of the plano-convex lens. A reflective polarizer may be formed on the planar surface of the plano-convex lens or the concave surface of the plano-concave lens. An additional quarter wave plate may be located between the reflective polarizer and the partially reflective mirror.

Abstract: Linear photo-oriented polymer (LPP) layers are situated to align liquid crystals in a liquid crystal polymer (LCP) layer situated at or on the LPP layers. The LCP layer can include a guest such as a fluorophore that aligns with the liquid crystal so as to emit polarized fluorescence in response to an excitation beam. Layer LPP/LCP structures can be provided as light emitters, patterned polarizers, patterned retarders and other devices based on selection of one or more guest materials included in the LCP and alignable with the liquid crystal.

Abstract: Linear photo-oriented polymer (LPP) layers are situated to align liquid crystals in a liquid crystal polymer (LCP) layer situated at or on the LPP layers. The LCP layer can include a guest such as a fluorophore that aligns with the liquid crystal so as to emit polarized fluorescence in response to an excitation beam. Layer LPP/LCP structures can be provided as light emitters, patterned polarizers, patterned retarders and other devices based on selection of one or more guest materials included in the LCP and alignable with the liquid crystal.