Abstract: A device includes a first-type liquid crystal (LC) lens configured to provide a first optical power that is variable in a first step resolution. The device also includes a second-type LC lens coupled with the first-type LC lens, and configured to provide a second optical power that is variable in a second step resolution. The first step resolution is smaller than the second step resolution. A total optical power of the device is a sum of the first optical power and the second optical power, and is variable in the first step resolution.

Abstract: Ghost image formation due to reflections of image light by a display panel to an ocular lens may be suppressed by ensuring that the image light reflected by the lens does not get reflected by the display panel back towards the lens. To that end, the display panel may include a quarter-wave birefringent layer between the top polarizer of the display panel and a layer inside the display panel that the image light reflects from, such as a black grid layer or an active matrix layer.

Abstract: A display assembly includes a light source, a spatial light modulator (SLM) and a grating. The light source is configured to emit illumination light, the SLM is configured to receive the illumination light and reflect at least a portion of the illumination light. The grating is positioned to redirect the illumination light output from the light source toward the SLM, receive at least a portion of the reflected light from the SLM, redirect first light having a first polarization toward the light source, and transmit through the grating second light having a second polarization that is orthogonal to the first polarization. Also disclosed are operations performed by the display assembly.

Abstract: Ghost images can interfere with eye tracking in a system that uses folded optics, such as is an artificial-reality display. Optical elements, such as waveplates and/or polarizers, can be used to attenuate or eliminate light causing the ghost images.

Abstract: A display device with a transparent illuminator and an liquid crystal (LC) display panel is disclosed. The transparent illuminator includes a light source and a transparent lightguide, which may be based on a slab of transparent material with zigzag light propagation of the illuminating light in the slab and/or a transparent photonic integrated circuit with singlemode ridge waveguides for spreading the illuminating light in a plane parallel to the plane of LC display panel. The lightguide includes a plurality of grating out-couplers whose position is coordinated with positions of LC pixels for higher throughput. A reflective offset-to-angle optical element may be provided to form an image in angular domain through the LC panel and through the transparent illuminator, resulting in an overall compact and efficient display configuration.

Abstract: A display panel has an array of pixels backlighted by a backlight including a lightguide and a plurality of out-coupling gratings. The locations of the out-coupling gratings are coordinated with positions of pixels in the array of pixels. The backlight may include a light-conducting transparent slab or an array of linear waveguides running parallel to the rows of the pixel array, with the gratings formed in the slab or in the waveguide. Wavelength composition and polarization of the light emitted by the waveguide may be matched to the transmission spectral bands and transmission polarization of the display panel.

Abstract: A varifocal system comprises a stacked first-type liquid crystal (LC) lens structure and a stacked second-type LC lens structure in optical series. The stacked first-type LC lens structure includes a plurality of first-type LC lenses, and a first-type LC lens provides continuously variable optical states in a first step resolution. The stacked second-type LC lens structure includes a plurality of second-type LC lenses and provides a plurality of optical states in a second step resolution. The first step resolution is smaller than the second step resolution, such that when the stacked second-type LC lens structure is switched between two optical states, the first-type LC lenses provide a continuous adjustment of optical power between the two optical states. The stacked first-type LC lens structure and the stacked second-type LC lens structure together provide a continuous adjustment range of optical power for the varifocal system.

Abstract: An optical assembly includes a first reflector and a second reflector. The first reflector is positioned to receive first light having a first polarization and provide the first light toward a first direction, and receive second light having the first polarization and provide the second light toward a second direction. The second reflector is positioned to receive the second light from the first reflector and reflect the second light back toward the first reflector. The first reflector receives light having a second polarization, having been reflected by the second reflector, and provide the light toward the first direction so that a first image corresponding to the first light and a second image corresponding to the second light are projected on a common image plane where at least a portion of the second image is located between two portions of the first image.

Abstract: An illumination system is provided. The illumination system includes a light source assembly configured to output a first polarized light having a first handedness. The illumination system also includes a light guide plate configured to guide the first polarized light received from the light source assembly and output a second polarized light having a second handedness opposite to the first handedness. The light guide plate includes two wedges coupled to one other at a slanted surface between the two wedges and a reflective polarizer disposed at the slanted surface. The illumination system also includes a reflective sheet arranged at a first side surface of the light guide plate and configured to reflect the first polarized light as the second polarized light. The reflective polarizer includes a birefringent material having a chirality, and is configured to selectively transmit the first polarized light and reflect the second polarized light.

Abstract: A waveplate is provided. The waveplate includes a first liquid crystal (“LC”) layer including LC molecules that are in-plane switchable by an external field to switch the waveplate between states of different phase retardances. The waveplate includes a second LC layer and a third LC layer sandwiching the first LC layer. Azimuthal angles of effective refractive index ellipsoids of the second LC layer and the third LC layer are different.

Abstract: An optical device is provided. The optical device includes a first optical element configured to output an elliptically polarized light having one or more predetermined polarization ellipse parameters. The optical device also includes a second optical element including a birefringent material with a chirality, and configured to receive the elliptically polarized light from the first optical element and reflect the elliptically polarized light as a circularly polarized light.

Abstract: An optical device includes a first layer including a first birefringent material having a negative birefringence dispersion property. The optical device also includes a second layer including a second birefringent material having a positive birefringence dispersion property. The first layer and the second layer are structurally patterned to provide at least one predetermined optical function.

Abstract: An optical waveplate is provided. The optical waveplate includes a plurality of liquid crystal (“LC”) layers stacked together. At least one of the plurality of LC layers includes LC molecules that are in-plane switchable by an external field to switch the optical waveplate between states of different phase retardances.

Abstract: A system is provided. The system includes a light source configured to emit an infrared light to illuminate an eye of a user. The system includes a grating disposed facing the eye and including a birefringent material film configured with a uniform birefringence lower than or equal to 0.1. The grating is configured to diffract the infrared light reflected from the eye, and transmit a visible light from a real world environment toward the eye, with a diffraction efficiency less than a predetermined threshold. The system includes an optical sensor configured to receive the diffracted infrared light and generate an image of the eye based on the diffracted infrared light.

Abstract: An optical device includes a light source and a polarization selective optical element. The polarization selective optical element includes a stack of a plurality of cholesteric liquid crystal layers. The plurality of cholesteric liquid crystal layers includes a first cholesteric liquid crystal layer with liquid crystal molecules arranged in a first helical configuration having a first pitch range for light of a first wavelength range and a second cholesteric liquid crystal layer with liquid crystal molecules arranged in a second helical configuration having a second pitch range for light of a second wavelength range. The second wavelength range is different from the first wavelength range.

Abstract: An example optical assembly includes a display, a light source for illuminating the display, and a first diffraction type polarizing beam splitter (DT-PBS) configured to direct light from a first light director, wherein the first DT-PBS is polarization sensitive and configured to direct, based on polarization, a first portion of light towards the display.

Abstract: An example eye-tracking optical assembly includes a light source for illuminating an eye, a first diffraction type polarizing beam splitter (DT-PBS), and a second DT-PBS, wherein the first DT-PBS is configured to direct, based on polarization, a first portion of light from the second DT-PBS towards an eye-tracking detector.

Abstract: An optical device and an eye-tracking system to suppress a rainbow effect are provided. The optical device includes a grating. The grating includes at least one substrate and a grating structure coupled to the at least one substrate. The grating structure is configured to diffract an infrared light beam and transmit a visible light beam with a diffraction efficiency less than a predetermined threshold.

Abstract: An optical device is provided. The optical device includes a first liquid crystal (“LC”) cell and a second LC cell stacked with the first LC cell. The first and second LC cells are configured to provide a phase retardation to a light transmitted therethrough. The optical device also includes at least one first compensation film disposed between the first LC cell and the second LC cell. The optical device also includes a second compensation film disposed at a first side of the first LC cell opposite to a second side of the first LC cell where the at least one first compensation film is disposed. The optical device also includes a third compensation film disposed at a first side of the second LC cell opposite to a second side of the second LC cell where the at least one first compensation film is disposed.

Abstract: An optical device is provided. The optical device includes a first optical element configured to output an elliptically polarized light having one or more predetermined polarization ellipse parameters. The optical device also includes a second optical element including a birefringent material with a chirality, and configured to receive the elliptically polarized light from the first optical element and reflect the elliptically polarized light as a circularly polarized light.