A wideband diffractive component capable of diffracting an incident beam exhibiting a wavelength lying in a diffraction spectral band, the diffractive component elementary areas arranged on a surface, each area belonging to a type indexed by an index i lying between 1 and n, with n greater than 1, index i corresponding to blaze wavelength λi of index i, the blaze wavelengths lying in the diffraction spectral band, an elementary area of type i comprising microstructures having at least a size less than 1.5 times the blaze wavelength of index i, the microstructures arranged to form an artificial material exhibiting an effective index variation such that an elementary area of type i constitutes a blazed diffractive element at the blaze wavelength λi of index i, the different values of the blaze wavelengths and the proportion of surface area occupied by the areas of a given type a function of a global diffraction efficiency desired in the diffraction spectral band.

The present disclosure relates to a distance measurement apparatus and a biometric authentication apparatus that are capable of conducting high-precise distance measurement even in intense light such as sunlight. A light source applies light to a subject. An image sensor captures an image of the subject. A distance measurement section calculates a distance to the subject on the basis of the image obtained by the image capturing. A transparent member is formed, on the image sensor, so as to be integrated with the image sensor. In addition, the transparent member includes a transmission film that allows a peak wavelength band of the light of the light source to transmit therethrough. The present disclosure is applicable to a biometric authentication apparatus, for example.

An optical assembly includes a volume grating configured to influence a beam direction of at least one light beam, and a switching device arranged in a beam path upstream of the volume grating. The switching device is configured to switch the beam direction and/or beam position of the at least one light beam from a first beam direction and/or beam position, in which the at least one light beam does not impinge on the volume grating at an acceptance angle of the volume grating, to a second beam direction and/or beam position, in which the at least one light beam impinges on the volume grating at the acceptance angle, and/or vice versa.

An optical system comprises an optically transmissive substrate comprising a metasurface which comprises a grating comprising a plurality of unit cells. Each unit cell comprises a laterally-elongated first nanobeam having a first width; and a laterally-elongated second nanobeam spaced apart from the first nanobeam by a gap, the second nanobeam having a second width larger than the first width. A pitch of the unit cells is 10 nm to 1 μm. The heights of the first and the second nanobeams are: 10 nm to 450 nm where a refractive index of the substrate is more than 3.3; and 10 nm to 1 μm where the refractive index is 3.3 or less.

A surface-relief grating includes a base surface-relief grating comprising a plurality of ridges that include a first material, and a second material on only a top surface or a single sidewall of each ridge of the plurality of ridges, where the second material is different from the first material. A method of fabricating the surface-relief grating includes etching or molding a base surface-relief grating that includes a plurality of ridges, depositing a material layer on the plurality of ridges, and selectively etching the material layer to increase a height or a slant angle of an edge of a ridge in the plurality of ridges to make the surface-relief grating that includes the base surface-relief grating.

A diffusion member includes a first layer and a second layer, in this order, wherein the first layer has a light transmissivity and a light diffusivity, in the second layer, a reflectance of light increases as an absolute value of an incident angle with respect to a first layer side surface of the second layer decreases, and a transmittance of light increases as an absolute value of an incident angle with respect to a first layer side surface of the second layer increases.

A display apparatus capable of providing an expanded viewing window includes a light guide plate including an input coupler and an output coupler; and an image providing apparatus facing the input coupler to provide an image to the input coupler. The input coupler may include a plurality of sub input couplers configured to propagate the image provided from the image providing apparatus at different angles in the light guide plate.

The light-guide plate includes a substrate, an incidence diffraction grating that diffracts incident light, and an emission diffraction grating that emits light from the substrate, the light being diffracted by the incidence diffraction grating. The emission diffraction grating is formed of a recessed/projected pattern formed on a substrate surface, the recessed/projected pattern includes a first group of parallel straight lines and a second group of parallel straight lines intersecting the first group of parallel straight lines, and a pitch of the first group of parallel straight lines is equal to a pitch of the second group of parallel straight lines. A relationship between the pitch P of the first group of parallel straight lines and the second group of parallel straight lines and a pattern width W of the recessed/projected pattern is defined as W/P, which is 0.15 or more and 0.85 or less.

An optical system comprises an optically transmissive substrate comprising a metasurface which comprises a grating comprising a plurality of unit cells. Each unit cell comprises a laterally-elongated first nanobeam having a first width; and a laterally-elongated second nanobeam spaced apart from the first nanobeam by a gap, the second nanobeam having a second width larger than the first width. A pitch of the unit cells is 10 nm to 1 μm. The heights of the first and the second nanobeams are: 10 nm to 450 nm where a refractive index of the substrate is more than 3.3; and 10 nm to 1 μm where the refractive index is 3.3 or less.

System, methods, and other embodiments described herein relate to a camera system. In one embodiment, the camera system includes a lens to receive light associated with an object and a first component, operatively connected to the lens, that inverts the light. The camera system also includes a second component, operatively connected to the first component, that resolves an angle of the light. A detector array, operatively connected to the second component, senses the light using a pixel to form an image to estimate depth of the object.