Abstract: An abrasive article can include a body including agglomerated first abrasive particles and unagglomerated second abrasive particles contained in a bond material. The first abrasive particles can include chromium oxide. The second abrasive particles can be elongated. The bond material can include an inorganic material including a vitreous phase.

Abstract: A display device includes a directional illuminator providing a light beam, a display panel downstream of a directional illuminator, for receiving and spatially modulating the light beam, and a beam redirecting module downstream of the display panel, for variably redirecting the spatially modulated light beam. Steering the illuminating light by the beam redirecting module enables one to steer the exit pupil of the display device to match the user's eye location(s).

Abstract: An image sensor includes imaging pixels and a patterned liquid crystal polarizer (LCP). The imaging pixel include subpixels. The patterned LCP is disposed over the subpixels and configured to direct a particular polarized portion of imaging light to particular subpixels.

Abstract: A device includes a display configured to generate an image light. The device also includes a waveguide optically coupled with the display and configured to guide the image light to an exit pupil of the device. The waveguide includes a grating including a birefringent material, and a birefringence of the grating is configured to increase along a pupil-expanding direction of the device.

Abstract: Provided is a polypeptide containing the amino acid sequence as shown in SEQ ID NO. 1, and the present invention belongs to the field of biomedicine. The polypeptide can inhibit the infection with novel coronavirus 2019-nCoV (SARS-CoV-2) and SARS-like viruses, and can thus provide good candidate drugs for the prevention and treatment of 2019-nCoV and SARS-like viruses which may break out in the future. Further provided is a polypeptide derivative having palmic acid or cholesterol modifications.

Abstract: A polarization modulator includes a first liquid crystal cell and a second liquid crystal cell. The first liquid crystal cell has a first type of liquid crystals configured to rotate an optical axis of light parallel to a first plane of the first liquid crystal cell. The second liquid crystal cell is configured to receive the light from the first liquid crystal cell. The second liquid crystal cell has a second type of liquid crystals configured to rotate the optical axis of the light perpendicular to a second plane of the second liquid crystal cell.

Abstract: A wavefront sensor for determining a wavefront of an impinging light beam includes a microlens array formed by nanoimprint lithography. Each microlens of the microlens array includes a plurality of concentric ridges separated by concentric grooves. A ratio F of a width of the concentric ridges to a pitch p of the concentric ridges is a function of a radial distance r from a microlens center to the concentric ridges. An effective refractive index n of microlenses depends on a fill ratio of a binary pattern, which depends on the radial distance from the microlens center. A photodetector array is disposed downstream of the microlens array and configured for receiving the plurality of light spots at the focal plane. An imaging optical rangefinder includes the wavefront sensor, a pulsed light source for emitting probing pulses, and a photodetector for receiving reflected light pulses.

Abstract: A display is provided. The display includes a plurality of light-emitting elements configured to emit a first light associated with a first predetermined wavelength band. The display also includes an optical assembly including a reflective polarizer, a color conversion layer, and a color filter layer. The optical assembly is configured to at least partially convert the first light associated with the first predetermined wavelength band into a second light associated with a second predetermined wavelength band, the second light being a polarized light of a predetermined polarization.

Abstract: An optical device includes an optical component (e.g., a polarization volume hologram, a geometric phase device, or a polarization-insensitive diffractive optical element) having a uniform thickness and configured to modify a wavefront of a light beam that includes light in two or more wavelengths visible to human eyes, where the optical component has a chromatic aberration between the two or more wavelengths. The optical device also includes a metasurface on the optical component. The metasurface includes a plurality of nanostructures configured to modify respective phases of incident light at a plurality of regions of the metasurface, where the plurality of nanostructures is configured to, at each region of the plurality of regions, add a respective phase delay for each of the two or more wavelengths to correct the chromatic aberration between the two or more wavelengths.

Abstract: A device is provided. The device includes a first polarization hologram element having a first operating wavelength band and configured to selectively backwardly diffract or transmit a first light associated with the first operating wavelength band based on a polarization of the first light. The device also includes a second polarization hologram element having a second operating wavelength band and stacked with the first polarization hologram. A thickness of the first polarization hologram element is configured based on a signal-to-noise ratio between a diffraction efficiency of the first polarization hologram element for the first light and a diffraction efficiency of the first polarization hologram element for a second light associated with the second operating wavelength band being greater than a predetermined value.

Abstract: A device is provided. The device includes a first polarization hologram element configured to operate as a half-wave plate for a first light having a first wavelength, and as a full-wave plate for a second light having a second wavelength. The device also includes a second polarization hologram element stacked with the first polarization hologram, and configured to operate as the half-wave plate for the second light and as the full-wave plate for the first light. The first polarization hologram element is configured to forwardly diffract or transmit the first light depending on a handedness of the first light. The second polarization hologram element is configured to forwardly diffract or transmit the second light depending on a handedness of the second light.

Abstract: A multilayer organic thin film includes a plurality of biaxially-oriented layers, where each layer is characterized by mutually orthogonal refractive indices, n1?n2?n3. In example structures, the corresponding in-plane refractive indices of adjacent layers may be rotated with respect to each other by a predetermined angle. Such a multilayer may be incorporated into a circular reflective polarizer, for example, which may be used in display systems to provide high broadband efficiency and high off-axis contrast. In an example process, individual organic thin films may be molded, and then oriented and stacked to form a multilayer.

Abstract: A system includes a diffractive optical element configured to receive a first beam and a second beam interfering with one another to generate a first interference pattern. The diffractive optical element is also configured to forwardly diffract the first beam and the second beam to output a third beam and a fourth beam. The third beam and the fourth beam interfere with one another to generate a second interference pattern. The system also includes a detector configured to detect the second interference pattern.

Abstract: An optical device includes a display configured to generate an image light; and a waveguide optically coupled with the display and configured to guide the image light to an exit pupil of the optical device. The waveguide includes an in-coupling element configured to couple the image light into the waveguide, and an out-coupling element configured to decouple the image light out of the waveguide. The out-coupling element includes a grating having a diffraction efficiency gradient along a predetermined direction at a plane of the grating.

Abstract: A system includes a light outputting element configured to output a first beam propagating toward a beam interference zone from a first side of the beam interference zone. The system also includes a reflective assembly configured to reflect the first beam back as a second beam propagating toward the beam interference zone from a second side of the beam interference zone. The first beam and the second beam interfere with one another within the beam interference zone to generate a polarization interference pattern.

Abstract: Methods and apparatus for extracting one or more mechanical properties for a material based on one or more indentation parameters for the material. The method comprises receiving load-displacement data from one or more instrumented indentation tests on the material, determining, by at least one computer processor, the indentation parameters for the material based, at least in part, on the received load-displacement data, providing as input to a trained neural network, the indentation parameters for the material, determining, based on an output of the trained neural network, the one or more mechanical properties of the material, and displaying an indication of the determined one or more mechanical properties of the material to a user of the computer system.

Abstract: A multifunctional liquid crystalline photoreactive polymer in which at least some of the polymer side-chains have an ultraviolet photoreactive moiety and at least some of the polymer side-chains have a calamitic mesogenic moiety are provided. At least some of the polymer side-chains have a photo-curable moiety a thermal-curable moiety. In some embodiments, the polymer is in the form of a co-polymer. In some embodiments, the polymer is in the form of a ter-polymer. The polymer is used in applications that require stable birefringement films. Such films are produced from the polymer by subjecting the polymer to ultra-violet light to cause side-chain cross-linking thereby inducing anisotropy. The anisotropy is then amplified by exposing the polymer to an elevated temperature.

Abstract: 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.

Abstract: A near eye display (NED) includes multiple PBP optical elements combined with one or more C-plates to improve optical angular performance. The PBP optical elements may be configured for beam steering or for focusing light to a point. A C-plate may reduce or eliminate an undesirable polarization phase shift introduced by the PBP optical elements to angular, off-axis light. Birefringence of the PBP optical elements produces such a polarization phase shift. A C-plate provides an additional polarization phase shift that is opposite to the extra polarization phase shift by the PBP optical elements. Thus, the additional polarization phase shift by the C-plate at least partially reduces the phase shift by the PBP element.

Abstract: A polarization conversion device includes a geometric phase grating and an angular selective waveplate. The geometric phase grating includes a first liquid crystal layer and is configured to diffract a unpolarized or partially polarized incident light beam into a first light beam and a second light beam (e.g., in two different diffraction orders). The first light beam is characterized by a first polarization state and propagates in a first direction. The second light beam is characterized by a second polarization state and propagates in a second direction. The angular selective waveplate includes a second liquid crystal layer, and functions as a zero or full-wave plate for the first light beam incident in the first direction and a half-wave plate for the second light beam incident in the second direction.