A display device includes a display panel including a substrate and a plurality of display elements disposed on the substrate, and a diffraction panel including a plurality of diffraction patterns disposed on a path of light emitted from the plurality of display elements. The plurality of diffraction patterns are disposed in a first direction to have a first period, each of the plurality of diffraction patterns includes a first refractive layer, a second refractive layer disposed on the first refractive layer, and a third refractive layer disposed on the second refractive layer, and a refractive index of the second refractive layer is higher than a refractive index of the first refractive layer and a refractive index of the third refractive layer.

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.

In a diffractive optical element including a base material, a first resin layer having a diffraction grating shape including plural concentric ring bands, and a second resin layer containing an inorganic particle, the inorganic particle is adjusted to have a number mean particle diameter of 10 nm or less, a first peak in a region in which particle diameters are 2 nm or more and 7.9 nm or less, and a second peak in a region in which particle diameters are larger than those of the first peak in a grain size distribution on a volumetric basis, with the ratio of the maximum intensity of the second peak to the maximum intensity of the first peak being 0.3 or more and 0.8 or less in a grain size distribution.

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.

An optical coupler includes a plurality of volume gratings in a substrate. The gratings include an array of fringes extending along length and thickness dimensions of the substrate. A difference between a refractive index of the fringes and a refractive index of the substrate depends on a depth coordinate along the thickness dimension of the substrate. A dependence of the difference on the depth coordinate has a bell-shaped function which suppresses ghost image formation due to optical crosstalk between gratings of neighboring spatial pitches.

A cycloidal diffractive waveplate based star simulator generates a star field with very high precision star locations and accurate brightness. The present disclosure provides a star simulator that allows for a large FOV, modular, multi-star simulator capable of very high precision dynamic star locations for testing of high accuracy, large FOV star trackers. The system is composed of a light source, a polarization grating-based image [1], and an opto-mechanical system for steering the light. The light is projected onto a diffuse screen where the light is scattered, creating a functional point source at the screen. A star tracker or other device under test views the screen which has a multitude of projected spots (each with its own light source and beam steering device) positioned in a star field distribution appropriate for the simulated viewing direction.

An optical device is formed by hot stamping a demetallized hologram to an optically variable foil or to a coating of optically variable ink. In another embodiment a hologram is hot stamped to a banknote or document printed with a color-shifting ink.

A laser device comprises a carrier, an optoelectronic component provided on the carrier, said component being designed to emit laser radiation, and an optical element designed to form the laser radiation emitted by the optoelectronic component, wherein: the optical element has a first layer that is at least partially transparent to the laser radiation, with a first refractive index, and a second layer that is at least partially transparent to the laser radiation, with a second refractive index; the first layer being applied to the optoelectronic component and having a surface with an imprinted structure; and the second layer is applied to the first layer, on the surface (24) having the imprinted structure.

Measurement method for interferometrically determining a shape of a test object (14) surface (12) includes arranging a first diffractive optical element (30, 130, 230) in an input wave (18) beam path, to generate a first test wave (34) with a wavefront that is adapted to a desired shape of the optical surface, detecting a first interferogram generated by the first test wave after interaction with the test object surface, arranging a different diffractive optical element (32, 232) in the input wave beam path for generating a further test wave with a wavefront which is adapted to the desired shape of the optical surface, the first and the further diffractive optical elements differing in their respective diffraction structure configurations, capturing a further interferogram generated by the further test wave after interaction with the test object surface, and determining the surface shape of the test object by calculating the two interferograms.

A diffractive optical device includes at least one diffractive optical element. The diffractive optical element generates light having a first order and light having a second order from a laser beam input to the diffractive optical element. The diffractive optical element includes a first phase pattern and a second phase pattern. The first phase pattern converts the laser beam into a line beam. The second phase pattern diffracts the laser beam in a short axis direction of the line beam to generate the light having the first order and the light having the second order. A first focal plane of the light having the first order is located at a position different from a second focal plane of the light having the second order on an optical axis of the laser beam.