An artifact mitigation system includes a projector assembly and a set of imaging optics optically coupled to the projector assembly. The artifact mitigation system also includes an eyepiece optically coupled to the set of imaging optics. The eyepiece includes a diffractive incoupling interface. The artifact mitigation system further includes an artifact prevention element disposed between the set of imaging optics and the eyepiece. The artifact prevention element includes a linear polarizer, a first quarter waveplate disposed adjacent the linear polarizer, and a color select component disposed adjacent the first quarter waveplate.

An optical component includes a phase diffraction grating and an amplitude diffraction grating. The phase diffraction grating includes a center concave section and a plurality of ring stages. The ring stages surround the center concave section. The center concave section and the ring stages form a cavity, where a light source is disposed in the cavity and emits the light to the optical component. Each of the ring stages has a stage surface. Each of the stage surfaces includes a plurality of ring microstructures arranged in concentric circles. The widths of each ring microstructure in at least one of the ring stages are less than the quarter wavelength of the light. The amplitude diffraction grating includes a center convex section and a plurality of ring parts. The center convex section and the center concave section are aligned. The ring parts surround the central convex section.

A light field imaging device and method are provided. The device can include a diffraction grating assembly receiving a wavefront from a scene and including one or more diffraction gratings, each having a grating period along a grating axis and diffracting the wavefront to generate a diffracted wavefront. The device can also include a pixel array disposed under the diffraction grating assembly and detecting the diffracted wavefront in a near-field diffraction regime to provide light field image data about the scene. The pixel array has a pixel pitch along the grating axis that is smaller than the grating period. The device can further include a color filter array disposed over the pixel array to spatio-chromatically sample the diffracted wavefront prior to detection by the pixel array. The device and method can be implemented in backside-illuminated sensor architectures. Diffraction grating assemblies for use in the device and method are also disclosed.

An optical element includes a substrate, an intermediate layer, a topmost layer, and a contiguous multitude of recessed and non-recessed areal regions. The intermediate layer is formed over a top surface of the substrate and has a refractive index n.sub.I. The topmost layer is formed directly on the intermediate layer and has a refractive index n.sub.T where n.sub.T≠n.sub.I. The intermediate and topmost layers are substantially transparent over an operational wavelength range that includes a design wavelength λ.sub.0. A subset of areal regions has a largest transverse dimension less than about λ.sub.0. Each non-recessed areal region includes corresponding portions of the intermediate and topmost layers. Each recessed areal region extends entirely through the topmost layer and at least partly through the intermediate layer. A fill medium fills the recessed areal regions. The areal regions are variously sized and distributed transversely across the optical element.

An optical phase grating produces an interference pattern rich in intensity and spatial-frequency information from the external scene. The grating includes an odd number of repeated sets of adjacent horizontal portions, separated by steps, that fill an area that radiates outward from a central region. At a given distance from the central region and within the area of the phase grating, each of the first horizontal portions is of a first width that differs from a second width of the adjacent second horizontal portions. The interference patterns produced by the grating can be processed to extract images and other information of interest about an imaged scene.

An object of the present disclosure is to provide a phase modulator, a lighting system, and a projector that allow for improving diffraction efficiency in a light phase modulation element. The phase modulator according to the present disclosure includes a light phase modulation element that has a plurality of pixels arranged with the pixel pitches p being different from each other to have a pixel structure suppressing occurrence of high-order diffraction light and that modulates a phase of light with respect to each of the pixels. Moreover, the phase modulator according to the present disclosure includes a capturing optical system that captures a plurality of fluxes of high-order diffraction light generated in each of the pixels.

Various embodiments set forth a foveated display system and components thereof. The foveated display system includes a peripheral display module disposed in series with a foveal display module. The peripheral display module is configured to generate low-resolution, large field of view imagery for a user's peripheral vision. The foveal display module is configured to perform foveated rendering in which high-resolution imagery is focused towards a foveal region of the user's eye gaze. The peripheral display module may include a diffuser that is disposed within a pancake lens, which is a relatively compact design. The foveal display module may include a Pancharatnam-Berry Phase grating stack that increases the steering range of a beam-steering device such that a virtual image can be steered to cover an entire field of view visible to the user's eye.

Several unique configurations for interferometric recording of volumetric phase diffractive elements with relatively high angle diffraction for use in waveguides are disclosed. Separate layer EPE and OPE structures produced by various methods may be integrated in side-by-side or overlaid constructs, and multiple such EPE and OPE structures may be combined or multiplexed to exhibit EPE/OPE functionality in a single, spatially-coincident layer. Multiplexed structures reduce the total number of layers of materials within a stack of eyepiece optics, each of which may be responsible for displaying a given focal depth range of a volumetric image. Volumetric phase type diffractive elements are used to offer properties including spectral bandwidth selectivity that may enable registered multi-color diffracted fields, angular multiplexing capability to facilitate tiling and field-of-view expansion without crosstalk, and all-optical, relatively simple prototyping compared to other diffractive element forms, enabling rapid design iteration.

Metasurfaces provide compact optical elements in head-mounted display systems to, e.g., incouple light into or outcouple light out of a waveguide. The metasurfaces may be formed by a plurality of repeating unit cells, each unit cell comprising two sets or more of nanobeams elongated in crossing directions: one or more first nanobeams elongated in a first direction and a plurality of second nanobeams elongated in a second direction. As seen in a top-down view, the first direction may be along a y-axis, and the second direction may be along an x-axis. The unit cells may have a periodicity in the range of 10 nm to 1 μm, including 10 nm to 500 nm or 300 nm to 500 nm. Advantageously, the metasurfaces provide diffraction of light with high diffraction angles and high diffraction efficiencies over a broad range of incident angles and for incident light with circular polarization.

An artifact mitigation system includes a projector assembly and a set of imaging optics optically coupled to the projector assembly. The artifact mitigation system also includes an eyepiece optically coupled to the set of imaging optics. The eyepiece includes a diffractive incoupling interface. The artifact mitigation system further includes an artifact prevention element disposed between the set of imaging optics and the eyepiece. The artifact prevention element includes a linear polarizer, a first quarter waveplate disposed adjacent the linear polarizer, and a color select component disposed adjacent the first quarter waveplate.