A freeform holographic imaging apparatus includes an imaging table for supporting a substrate, an imaging beam positioned adjacent to the imaging table; and a controller operatively connected to the imaging beam and configured to control a position of the imaging beam with respect to the imaging table. The controller is configured to control the imaging beam to image first and second holographic optical elements on the substrate, wherein each of the first and second holographic optical elements are a single pixel. The first holographic optical element is imaged according to a first parameter set and the second holographic optical element is imaged according to a second parameter set.

The present disclosure provides an apparatus for manufacturing a diffractive optical element, the apparatus including: a prism for manufacturing a diffractive optical element, the prism comprising a photoreactive material attachment surface and a light reflecting surface inclined at a predetermined angle from the photoreactive material attachment surface; and a light source positioned at the opposite side of the prism with respect to the photoreactive material attached to the photoreactive material attachment surface, and configured to irradiate light toward the photoreactive material, and a method for manufacturing a diffractive optical element.

A method for recording a diffractive nanostructure is provided. The method includes: providing a holographic recording mixture including a monomer, an inert material, and a photoinitiator; depositing a layer of the mixture onto a substrate; exposing the mixture to a holographic recording beam to form a nanostructure of polymer regions and inert material regions within the mixture layer; and depositing a surface-conditioning optical layer on top of the nanostructure after curing of the expose mixture.

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.

Here discloses a method for duplicating a hologram and a hologram optical element. The method comprises: preparing a master with a master hologram; preparing a sample with coated photoalignment material layer above the master; and irradiating a recording light through the sample to the master, so that at least one portion of the recording light is reflected by the master as an object light carrying the master hologram information, and so that the object light and the recording light are interfered at the photoalignment material layer to produce a duplicated hologram in the photoalignment material layer.

Methods, devices and systems are described that enable monitoring the diffraction efficiency of holographic material in real-time while they are being formed. One example method includes directing a reference beam and an object beam toward a holographic material for formation of a diffraction grating and blocking one of the beams for at least a portion of time during which the diffraction grating is being formed. The method further includes, upon blockage of one of the beams, based on power level measurements, determining whether or not a first diffraction efficiency is reached. If the first diffraction efficiency is reached, one of the reference or the object beams is disabled or blocked while the other beam illuminates the holographic material with a particular duty cycle. Further measurements of the diffraction efficiency are made until the final diffraction efficiency is reached.

The invention relates to a method for producing a holographic optical element by providing a recording stack comprising at least one recording element laminated on at least one supporting element, irradiating at least a part of the recording stack with at least one recording beam in an irradiating step, wherein during the irradiating step, the recording stack bends, providing a bending deviation threshold for the recording stack, and adjusting at least one first process parameter such that an expected maximum bending deviation of the recording stack does not exceed the bending deviation threshold, wherein the at least one first process parameter influences the bending behavior of the recording stack during the irradiating step.

A display device includes an optical sensor configured to image a user eye, an image source configured to provide image light, a holographic film including a plurality of holograms, and a controller. Each hologram is recorded with a same reference beam but recorded differently so as to differently diffract image light received from the light source. The controller is configured to determine, via the optical sensor, a position of the user eye, and adjust, based on the determined position of the user eye, a state of the holographic film such that a particular hologram of the plurality of holograms diffracts image light to the position of the user eye.

In a process of manufacturing the volume holographic element, a holographic material layer is irradiated with reference light from the side of a second substrate in the oblique direction, and the holographic material layer is vertically irradiated with object light from the side of a first substrate in an interference exposure process. Since a first translucent anti-reflective layer is formed on the first surface of the first substrate, it is difficult that a situation in which the reference light is reflected in the first surface in the oblique direction occurs. In addition, since a second translucent anti-reflective layer is formed on the second surface of the second substrate, it is difficult that a situation in which the object light is reflected in the second surface occurs.

A method for design and fabrication of holographic optical elements for a compact holographic sight is proposed. The method includes use of ray-trace software to design holographic elements having optical power using an intermediate hologram with parameters obtained through minimization of the merit function defining image quality.