An optical device includes a first polarization selective reflector positioned in a first orientation so that the first polarization selective reflector: receives first light in a first direction; redirects a first portion, of the first light, having a first polarization to a second direction that is non-parallel to the first direction; and receives second light in a third direction and transmit a first portion, of the second light. A second polarization selective reflector positioned in a second orientation non-parallel to the first orientation, and adjacent to the first polarization selective reflector so that the second polarization selective reflector: receives third light in a fourth direction; redirects a first portion, of the third light, having the first polarization to a fifth direction that is non-parallel to the fourth direction; and receives fourth light in a sixth direction and transmit a first portion, of the fourth light having the second polarization.

An apparatus includes a precursor dispenser for dispensing a precursor material into a workspace, one or more acoustic sources configured to direct acoustic waves towards the workspace to provide acoustic fields that arrange the precursor material in a three-dimensional shape in the workspace, one or more sensors configured to detect a distribution of the precursor material in the workspace, and an electronic controller in communication with the precursor dispenser, the one or more acoustic sources, and the one or more sensors, the electronic controller being programmed to cause the one or more acoustic sources to adjust the acoustic fields to reduce deviations in the distribution of the precursor material from the three-dimensional shape in the workspace.

A method for producing holograms with a multiplicity of holographic prescriptions from a single master is provided. A multiplicity of holographic substrates each containing a first hologram is stacked on a second holographic recording medium substrate. The first hologram is designed to diffract light from a first direction into a second direction. When expose to illumination from the first direction zero order and diffracted light from each first hologram interfere in the second holographic recording medium substrate forming a second hologram. The second hologram is then copied into a third holographic recording medium substrate to provide the final copy hologram.

A lighting device for a vehicle, in particular a headlamp for a vehicle, having at least one light source, from which light emanates during the operation of the lighting device, a diffractive optical unit, including a plurality of gratings, which form a grating cell array, the light passing through the grating cell array during the operation of the lighting device in such a way that a light distribution is created in the outer area of the vehicle, at least one of the gratings of the grating cell array being designed as a volume hologram.

To provide an authentication device and method for a security medium including a reflective volume hologram, capable of easily performing authentication determination and a security medium including the reflective volume hologram.

An authenticity determination device 1 for a security medium 10 including a reflective volume hologram 2 includes a light source L disposed on the front surface side of the reflective volume hologram 2 so that light emitted therefrom is incident on the reflective volume hologram 2, a first observation device 11 disposed in a pre-designed diffraction direction of the reflective volume hologram 2, and a second observation device 12 disposed in a direction other than the pre-designed diffraction direction of the reflective volume hologram 2. Light including a pre-designed diffraction wavelength is emitted from the light source L to be incident on the reflective volume hologram 2, and at this time, when the light amount observed in the first observation device 11 is larger in the diffraction wavelength than in other wavelengths, and the light amount observed in the second observation device 12 is smaller in the diffraction wavelength than in other wavelengths, it is determined that the reflective volume hologram 2 is genuine.

A vision system for a vehicle includes a camera disposed at a vehicle and having a field of view exterior of the vehicle. The camera includes a lens and a pixelated imaging array having a plurality of photosensing elements. The camera includes a volume hologram disposed between the lens and the imaging array. The volume hologram may function as a spatial low pass filter with a steep filtering slope. An image processor is operable to process image data captured by the camera.

A system for making a holographic medium for use in generating light patterns for eye tracking includes a light source configured to provide light and a beam splitter configured to separate the light into a first portion of the light and a second portion of the light that is spatially separated from the first portion of the light. The system also includes a first set of optical elements configured to transmit the first portion of the light for providing a first wide-field beam onto an optically recordable medium, a second set of optical elements configured to transmit the second portion of the light for providing a second wide-field beam, and a plurality of parabolic reflectors optically coupled with the second set of optical elements and configured to receive the second wide-field beam and project a plurality of separate light patterns onto the optically recordable medium for forming the holographic medium.

The layered generation of at least one volume grating in a recording medium by way of exposure, the recording medium having at least one photosensitive layer which is sensitized for a presettable wavelength of the exposure light. Each volume grating is generated in the recording medium by at least two wave fronts of coherent light capable of generating interference, the wave fronts being superposed in the recording medium at a presettable depth, at a presettable angle and with a presettable interference contrast. The depth and the thickness of the refractive index modulation and/or transparency modulation of a volume grating in the recording medium is controlled by depth-specific control of the spatial and/or temporal degree of coherence of the interfering wave fronts in the direction of light propagation.

A lighting device for vehicles, in particular a signal light, with a light source for emitting a light beam and an optical unit associated with the light source for producing a predetermined light function, the optical unit having a holographic element and a lens arranged in the main emission direction in front of the holographic element, the holographic element comprising such a diffraction structure that the light beam emitted from the light source onto the holographic element is varied according to a predetermined illumination pattern such that the holographic light beam lights an illumination surface of the lens to generate the light function.

An image display device according to an aspect of the present technology includes an emission portion, a transparent base material, an irradiation target, and an optical portion. The emission portion emits image light along a predetermined axis. The transparent base material includes a tapered surface having a tapered shape along the predetermined axis. The irradiation target is disposed at at least a part around the predetermined axis along the tapered surface. The optical portion controls an incident angle of the image light on the irradiation target, the image light having been emitted from the emission portion, the optical portion being disposed in a manner that the optical portion faces the emission portion on the basis of the predetermined axis.