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 wavefront shaping assembly disposed at a second side of the beam interference zone and including a polarization hologram, the wavefront shaping assembly being configured to reflect the first beam as a second beam propagating toward the beam interference zone from the second side. The first beam and the second beam are linearly polarized beams, and are configured to interfere with one another within the beam interference zone to generate an interference pattern that is recordable in a recording medium layer disposed in the beam interference zone.

A volume holographic film (such as a photopolymer) that is pre-recorded with patterns subsequently is used to encode LED or low-power laser light reflections from an eye into a binary pattern that can be read at very high speeds by a relatively simple complementary metal-oxide-semiconductor (CMOS) sensor that may be similar to a high framerate, low resolution mouse sensor. The low-resolution mono images from the film are translated into eye poses using, for instance, a look up table that correlates binary patterns to X, Y positions or using a pre-trained convolutional neural network to robustly interpret many variations of the binary patterns for conversion to X, Y positions.

A system is provided. The system includes a light source configured to emit an infrared light to illuminate an eye of a user. The system includes a grating disposed facing the eye and including a birefringent material film configured with a uniform birefringence lower than or equal to 0.1. The grating is configured to diffract the infrared light reflected from the eye, and transmit a visible light from a real world environment toward the eye, with a diffraction efficiency less than a predetermined threshold. The system includes an optical sensor configured to receive the diffracted infrared light and generate an image of the eye based on the diffracted infrared light.

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.

The purpose of the present invention is to provide a hologram reproducing apparatus and a hologram reproducing method, which are suitable for reproducing hologram. The purpose can be achieved by means of a hologram reproducing apparatus, which reproduces information signals by irradiating an optical information recording medium with reference light, and a hologram reproducing method for the hologram reproducing apparatus. The hologram reproducing apparatus is characterized in being provided with: a polarization conversion section, which converts polarization of diffracted light that is generated when the optical information recording medium is irradiated with the reference light; a light receiving section, which receives the diffracted light having the polarization thereof converted by means of the polarization conversion section; and a servo signal generating circuit section, which generates signals for moving the optical information recording medium or the polarization conversion section using the diffracted light received by means of the light receiving section.

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.

It is possible to provide a new information recording/reproduction method and a device which can realize a small-size large-capacity memory having a characteristic equivalent to or higher than a hologram memory. The optical information recording/reproduction device includes: recording light generator (51) which generates a recording light (55) in a polarization state having two mutually orthogonal polarization components with a phase difference at an arbitrary polarization base; reproduction light generator (61) which generates a reproduction light (65) in a polarization state having only a single polarization component at a arbitrary polarization basis; recording medium (71) in which optical information is recorded by recording light (55) and the recorded optical information is reproduced by reproduction light; and optical information detector (polarimeter 81) which retrieves information light (72) after being applied to recording medium (71) and detects the light as optical information. Provided is also an optical information recording/reproduction method using the device.

A holographic characterization and playback apparatus is provided, which includes a light source, an optical path-forming optical system for separating the light emitted from the light source into a probe light and a reference light of different polarizations, and combining optical paths of the probe light and the reference light.

A system is provided. The system includes a light source configured to emit an infrared light to illuminate an eye of a user. The system includes a grating disposed facing the eye and including a birefringent material film configured with a uniform birefringence lower than or equal to 0.1. The grating is configured to diffract the infrared light reflected from the eye, and transmit a visible light from a real world environment toward the eye, with a diffraction efficiency less than a predetermined threshold. The system includes an optical sensor configured to receive the diffracted infrared light and generate an image of the eye based on the diffracted infrared light.

A holographic imaging system comprises an imaging light source defining an imaging light path, an active light source defining an active light path directed at a target, a polarizer configured to modify the polarization of the active light path, a polarization beam splitter positioned in the active light path and the imaging light path, configured to separate the active light path and the imaging light path, and a photodetector positioned at a terminus of the active light path, configured to measure a reflection of the active light source. A method of holographic imaging is also described.