Image-sensing devices include odd-symmetry gratings that cast interference patterns over a photodetector array. Grating features offer considerable insensitivity to the wavelength of incident light, and to the manufactured distance between the grating and the photodetector array. Photographs and other image information can be extracted from interference patterns captured by the photodetector array. Images can be captured without a lens, and cameras can be made smaller than those that are reliant on lenses and ray-optical focusing.

An optical structure is provided. The optical structure includes an optical element and a plurality of protrusions. The optical element has a planarized top surface. The plurality of protrusions are disposed on the planarized top surface, wherein each of the plurality of protrusions independently has a size in the subwavelength dimensions.

An optical coupler device comprises a substrate having a substantially planar upper surface, and a grating structure on the upper surface of the substrate. In one embodiment, the grating structure comprises a copropagating array of waveguides that are substantially parallel to each other and extend along at least a portion of the upper surface of the substrate. Each of the waveguides has opposing sidewalls, wherein a width of each waveguide is defined by a distance between the opposing sidewalls. The opposing sidewalls each have a periodic structure that produces a sidewall modulation for each of the waveguides. An input port is in optical communication with the grating structure. The input port is configured to direct an input light beam in plane into the grating structure such that the beam propagates along the waveguides. The grating structure is configured to diffract the beam out of plane and into free space.

A terahertz wave lens includes a substrate having a surface provided with an uneven structure that changes a phase of the terahertz wave. The uneven structure includes a plurality of holes that are periodically arranged. The uneven structure includes a plurality of regions where the plurality of holes are arranged. A height of the hole in a thickness direction of the substrate and a width of the pillar differ for each of the regions. Outer end portions of the uneven structure in the thickness direction are located on the same plane.

A terahertz wave lens includes a substrate having a surface provided with an uneven structure that changes a phase of the terahertz wave. The uneven structure includes a plurality of holes that are periodically arranged. The uneven structure includes a plurality of regions where the plurality of holes are arranged. A height of the hole in a thickness direction of the substrate and a width of the pillar differ for each of the regions. Outer end portions of the uneven structure in the thickness direction are located on the same plane.

The present disclosure describes diffractive optical elements (DOEs) and master tools for producing the DOEs. In one aspect, the disclosure describes a method that includes modifying a first pixel layout design for diffractive optical elements to obtain a modified pixel layout design. The first pixel layout design comprises pixels, each of which has a shape of a regular polygon (e.g., a rectangular shape). Modifying the first pixel layout design includes approximating a shape contour of a cluster of pixels in the first pixel layout design by a single polygon that reduces a total number of edges relative to the shape contour of the cluster of pixels in the first pixel layout design. The method also includes using the modified pixel layout design to form a master tool for production of the diffractive optical elements.

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 η.sub.I. The topmost layer is formed directly on the intermediate layer and has a refractive index η.sub.T where η.sub.T ≠ η.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.

A waveguide structure is provided. The waveguide structure includes waveguide combiners stacked one upon the other. Each waveguide combiner includes a waveguide plate and an input coupler disposed on the waveguide plate. The input coupler of at least one waveguide combiner includes first grating pillars, and each first grating pillar has a gradually changing refractive index.

Provided is a meta optical device including a plurality of phase modulation regions respectively including a plurality of nanostructures that have shapes and arrangement based on a preset rule, the plurality of phase modulation regions being configured to modulate a phase of incident light of a preset wavelength band, wherein at least two phase modulation regions of the plurality of phase modulation regions have phase modulation ranges in a first direction that are same, and wherein the plurality of nanostructures included in the at least two phase modulation regions have width ranges in the first direction that are different from each other.

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.