An illuminator usable for illuminating a display panel is disclosed. The illuminator uses a pupil-replicating waveguide to expand a pair of light beams propagating in the waveguide. The light beams may be coupled at a same edge and/or at opposite edges of the waveguide, and are configured to fill each other's dark spots between out-coupled beam portions of the light beams. To improve the illumination uniformity, the two light beams may be orthogonally polarized, and the out-coupling grating strength may be spatially varied along the waveguide.

Display devices include waveguides with metasurfaces as in-coupling and/or out-coupling optical elements. The metasurfaces may be formed on a surface of the waveguide and may include a plurality or an array of sub-wavelength-scale (e.g., nanometer-scale) protrusions. Individual protrusions may include horizontal and/or vertical layers of different materials which may have different refractive indices, allowing for enhanced manipulation of light redirecting properties of the metasurface. Some configurations and combinations of materials may advantageously allow for broadband metasurfaces. Manufacturing methods described herein provide for vertical and/or horizontal layers of different materials in a desired configuration or profile.

A head-up display capable of adjusting an imaging position is provided. The head-up display includes an image generation module, a reflector, a holographic diffraction optical element and a control unit. The image generation module is configured to display and project an image. The reflector is configured to reflect the image and further project the image on a transparent screen through the reflector. The holographic diffraction optical element is disposed on the transparent screen to reflect the image to a visible range of the user's eyes. The control unit is coupled to the reflector or the transparent screen to adjust the viewing angle of the holographic diffraction optical element having a pre-determined angle with the reflector.

Various embodiments may relate to an optical system. The optical system may include a lens structure configured to generate an outgoing Gaussian beam based on an incoming Gaussian beam. The optical system may also include a light source configured to provide the incoming Gaussian beam to the lens structure. The lens structure may be a flat lens or a phase plate.

An image display apparatus according to an embodiment of the present technology includes a plurality of display units. Each of the display units includes a screen on which an object image is formed; and a diffractive optical element that includes a first surface and a second surface that is situated opposite to the first surface, the diffractive optical element diffracting image light of the object image that enters the first surface, and causing the image light to exit the first surface, the diffractive optical element displaying a virtual image of the object image on a side of the second surface such that the virtual image is superimposed on a background. The diffractive optical elements of a plurality of the diffractive optical elements included in the display units are each arranged to at least partially surround a specified axis in a state in which the second surface faces the specified axis.

Apparatus and methods for altering one or more spectral, spatial, or temporal characteristics of a light-emitting device are disclosed. Generally, such apparatus may include a volume Bragg grating (VBG) element that receives input light generated by a light-emitting device, conditions one or more characteristics of the input light, and causes the light-emitting device to generate light having the one or more characteristics of the conditioned light.

A virtual image generation system comprises a planar optical waveguide having opposing first and second faces, an in-coupling (IC) element configured for optically coupling a collimated light beam from an image projection assembly into the planar optical waveguide as an in-coupled light beam, a first orthogonal pupil expansion (OPE) element associated with the first face of the planar optical waveguide for splitting the in-coupled light beam into a first set of orthogonal light beamlets, a second orthogonal pupil expansion (OPE) element associated with the second face of the planar optical waveguide for splitting the in-coupled light beam into a second set of orthogonal light beamlets, and an exit pupil expansion (EPE) element associated with the planar optical waveguide for splitting the first and second sets of orthogonal light beamlets into an array of out-coupled light beamlets that exit the planar optical waveguide.

An illuminator for a display panel includes a light source for providing a light beam and a lightguide coupled to the light source for receiving and propagating the light beam along the substrate. The lightguide includes an array of out-coupling gratings that runs parallel to the array of pixels for out-coupling portions of the light beam from the lightguide such that the out-coupled light beam portions propagate through the substrate and produce an array of optical power density peaks at the array of pixels due to Talbot effect. A period of the array of peaks is an integer multiple of a pitch of the array of pixels.

Provided are a Fourier-beam shaper and a display apparatus including the Fourier-beam shaper. The Fourier-beam shaper includes: a waveguide; an input coupler configured to direct a plurality of light beams toward the waveguide in a time-sequential manner; and a spatial converter configured to output the plurality of light beams traveling in the waveguide through spatially different regions of the spatial converter.

Aspects of the present disclosure relate to depth sensing using a device. An example device includes a light projector configured to project light in a first and a second distribution. The first and the second distribution include a flood projection when the device operates in a first mode and a pattern projection when the device operates in a second mode, respectively. The example device includes a receiver configured to detect reflections of light projected by the light projector. The example device includes a processor connected to a memory storing instructions. The processor is configured to determine first depth information based on reflections detected by the receiver when the device operates in the first mode, determine second depth information based on reflections detected by the receiver when the device operates in the second mode, and resolve multipath interference (MPI) using the first depth information and the second depth information.