Abstract: A method includes providing a radiation with a predetermined intensity profile. The method also includes providing a photo-sensitive medium layer including a mixture of a photo-sensitive material and an absorbing additive. The absorbing additive has a predetermined non-uniform distribution in at least one of a direction within a film plane or a thickness direction of the photo-sensitive medium layer. The predetermined non-uniform distribution of the absorbing additive is configured to result in a predetermined non-uniform absorption of the radiation. The method also includes exposing the photo-sensitive medium layer to the radiation to form a polymer film. The optical film includes at least one predetermined birefringence variation in at least one of a direction within a film plane or a thickness direction of the polymer film.

Abstract: The application provides a fabricated building block processing device. In order to solve the problem that the single-layer integrated thermal insulation layer is easy to be gnawed and hollowed out by rats, and the clamping block of the clamping scheme is easy to break, the application adopts the filling block channel and the filling plate channel on the limiting shell to form the limiting channel of the multi-area double-layer thermal insulation layer structure, which is aligned with the second block body. After the filling block and the filling plate are sent into the limiting channel, the filling block and the filling plate are directly pushed into the second block body on the assembly line through the upper and lower double-layer first and second conveyor belts, and finally the filling block and the filling plate exposed outside the second block body are cut off to form a complete prefabricated building block.

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: A device includes a plurality of electrode layers. The device also includes a birefringent medium layer disposed between the plurality of electrode layers. The device also includes at least one alignment structure disposed at a surface of the birefringent medium layer. The birefringent medium layer includes liquid crystal molecules arranged in a plurality of helical twist structures having a helical axis. The plurality of electrode layers are configured to generate an electric field within the birefringent medium layer, and the liquid crystal molecules are aligned via the electric field to be titled with respect to the helical axis.

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: A computer-implemented method may include (1) causing a radar component to emit one or more radar signals and (2) causing the radar component to analyze one or more return signals. Also disclosed is a method for forming a 3D liquid crystal polarization hologram optical element and a method for characterizing diffractive waveguides includes directing light onto a structure and measuring the diffracted light to capture at least one image of the structure. Lastly, disclosed is a method of pattering organic solid crystals and a method directing a beam of input light to a surface of an optical material to determine crystallographic and optical parameters of the optical material. Various other methods, systems, and computer-readable media are also disclosed.

Abstract: A device is provided. The device includes a light guide configured to guide a first light propagating therein. The device also includes an optical film coupled with the light guide, optically anisotropic molecules in the optical film being configured with an in-plane orientation pattern having an in-plane pitch along the predetermined in-plane direction. Within the in-plane pitch of the in-plane orientation pattern, azimuthal angles of the optically anisotropic molecules are configured to vary nonlinearly along the predetermined in-plane direction. The optical film is configured to diffract the first light as a plurality of second lights at a plurality of locations of the optical film, with a plurality of predetermined, different diffraction efficiencies.

Abstract: A device is provided. The device includes a light guide configured to guide a first light propagating therein. The device also includes an optical film coupled with the light guide, optically anisotropic molecules in the optical film being configured with an in-plane orientation pattern having an in-plane pitch along the predetermined in-plane direction. Within the in-plane pitch of the in-plane orientation pattern, azimuthal angles of the optically anisotropic molecules are configured to vary nonlinearly along the predetermined in-plane direction. The optical film is configured to diffract the first light as a plurality of second lights at a plurality of locations of the optical film, with a plurality of predetermined, different diffraction efficiencies.

Abstract: A first layer of anisotropic material extends along a first plane and includes anisotropic components being parallel to a second plane non-parallel and non-perpendicular to the first plane. The anisotropic components are arranged in cycloidal or helical patterns. The cycloidal or helical patterns define one or more Bragg planes that are non-parallel and non-perpendicular to the first plane and either substantially parallel or substantially perpendicular to the second plane.

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 device includes a Pancharatnam-Berry phase (“PBP”) film stack configured to diffract an input beam as a first polarized beam and a second polarized beam having opposite handednesses. A combined diffraction efficiency of the PBP film stack for the first and second polarized beams is greater than a predetermined value. The device also includes a compensation film stack coupled with the PBP film stack, and configured to respectively convert the first polarized beam and the second polarized beam into a third polarized beam and a fourth polarized beam having the opposite handednesses. The first and second polarized beams include at least one elliptically polarized beam, and the third and fourth polarized beams are two circularly polarized beams. The compensation film stack is configured to convert the at least one elliptically polarized beam into at least one of the two circularly polarized beams.

Abstract: A device is provided. The device includes an optical film including optically anisotropic molecules configured to form a plurality of helical structures with a plurality of helical axes and a helical pitch. The helical pitch is a distance along a helical axis over which an azimuthal angle of an optically anisotropic molecule vary by a predetermined value. Over the helical pitch of a helical structure, the azimuthal angle of the optically anisotropic molecule is configured to vary nonlinearly with respect to a distance from a starting point of the helical pitch to a local point at which the optically anisotropic molecule is located along the helical axis.

Abstract: An optical diffuser includes optically anisotropic molecules arranged in a predefined configuration such that the optical diffuser diffuses first light having a first polarization and transmits second light having a second polarization that is different from the first polarization upon receiving the second light. In addition to polarization selectivity, the optical diffuser may also exhibit wavelength selectivity and/or incident angle selectivity. A method of diffusing light using the optical diffuser and a method of making the optical diffuser are also disclosed.

Abstract: A system is provided for generating a polarization interference pattern. The system includes a light source configured to output a first beam having a predetermined wavelength. The system includes a transmissive polarization volume hologram (“PVH”) mask configured to provide a predetermined diffraction efficiency to a second beam having the predetermined wavelength, a circular polarization, and a non-zero incident angle at the transmissive PVH mask. The system includes a light deflecting element disposed between the light source and the transmissive PVH mask, and configured to deflect the first beam as the second beam toward the transmissive PVH mask. The transmissive PVH mask is configured to forwardly diffract the second beam incident thereon as a third beam and a fourth beam having orthogonal circular polarizations, a substantially same light intensity, and symmetric propagation directions. The third beam and the fourth beam interfere with one another to generate the polarization interference pattern.

Abstract: A computer-implemented method is disclosed. The method includes: receiving, from a web server associated with a protected resource, a first signal including a request to validate a bearer token submitted by a client device to the web server, the bearer token including a digital signature; validating the bearer token, the validating including verifying the digital signature using a public key associated with an end user of the client device; and in response to validating the bearer token, sending to the web server a second signal including a notification that the bearer token is valid.

Abstract: A system includes a diffractive optical element including at least one substrate and a grating structure. The grating structure is configured to diffract a first light having an incidence angle within a predetermined range, and the at least one substrate is configured to reflect a second light. The system also includes a polarization selective mechanism configured to generate images based on the first light and the second light, respectively.

Abstract: A system includes a mask configured to forwardly diffract an input beam as a first set of two polarized beams. The system also includes a polarization conversion element configured to convert the first set of two polarized beams into a second set of two polarized beams having opposite handednesses. The two polarized beams having opposite handednesses interfere with one another to generate a polarization interference pattern.

Abstract: A system includes a surface relief grating configured to forwardly diffract an input beam as two linearly polarized beams. The system also includes a waveplate optically coupled with the surface relief grating and configured to convert the two linearly polarized beams into two circularly polarized beams having orthogonal circular polarizations. The two circularly polarized beams having orthogonal circular polarizations interfere with one another to generate a polarization interference pattern.

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 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.