The present disclosure discloses a method and apparatus for preparing a femtosecond optical filament interference direct writing volume grating/chirped volume grating. The method is characterized in that optical filaments are formed in glass by using femtosecond pulse laser, and plasma is controlled to quickly scan in the glass and etch a volume grating or chirped volume grating structure by adjusting the focal length of convex lens, laser energy and movement of motor machine. The apparatus includes a femtosecond pulse laser module, a pulse chirp management module, a pulse time domain shaping module, a laser separation and interference module, a glass volume grating processing platform module and a camera online imaging module.

Provided is a hologram image normalization method for a holographic printer. In a holographic printing method according to an embodiment, generating, encoding, and normalizing for the (n+1)-th hogel are performed in parallel with loading and recording of a normalized hologram for the n-th hogel, and moving and waiting for the (n+1)-th hogel. Accordingly, a global maximum value and a global minimum value for normalization may be calculated as approximate estimation values, and a hologram generation process and a printing process may be performed in parallel, so that a total printing time may be minimized and memory usage may be optimized when holographic printing is performed.

Systems, devices, and methods for eyebox expansion in wearable heads-up displays (WHUD) are described. A WHUD includes a support structure, a scanning laser projector (SLP), a split mirror, an optical splitter, and a holographic combiner. When the WHUD is worn on the head of a user the holographic combiner is positioned in a field of view of the user. The SLP scans light signals onto the split mirror which reflects the light signals onto the optical splitter. The optical splitter redirects the light signals towards the holographic combiner such that subsets of the light signals originate from spatially-separated virtual positions. The holographic combiner redirects the light to the eye resulting in spatially-separated exit pupils. The spatial separation of the exit pupils results in an expanded eyebox. The indirect path of light from SLP to optical splitter enables a smaller and therefore more aesthetically desirable design for the WHUD.

Embodiments of this application provide example holographic recording media, holographic polymer materials, methods for preparing holographic polymer materials, and display devices. An example holographic recording medium includes a first-order crosslinked network, a photoinitiator, and a second-order monomer. The first-order crosslinked network provides a mechanical support for the holographic recording medium. The second-order monomer includes a monomer with a free radical reactivity. The photoinitiator is used to initiate polymerization of the second-order monomer. The holographic recording medium includes at least one of an ester group (I), a urethane group (II), a carbamido group (III), an allophanate group (IV), or an amide group (V). Groups linked to the ester group (I), the urethane group (II), the carbamido group (III), the allophanate group (IV), and the amide group (V) are separately selected from at least one of the following: alkyl, alkoxy, alkenyl, or aryl.

An apparatus for suppressing electron/hole recombination includes a photonic device that generates electron/hole pairs responsive to a light beam interacting with the photonic device. An orbital angular momentum (OAM) generation device is located to impart an orbital angular momentum to a light beam before the light beam interacts with the photonic device. The electron/hole pair recombination generated from an OAM imparted light beam is less than electron/hole pair recombination of a non-OAM imparted light beam.

A hologram recording composition includes at least: a photopolymerizable compound containing at least a first photopolymerizable monomer; binder resin that is inactive to photopolymerization; and a photopolymerization initiator. A change in polarity of the first photopolymerizable monomer by photopolymerization reduces compatibility with the binder resin of the photopolymerizable compound than that before polymerization, the compatibility of the photopolymerizable compound before the polymerization being high.

A display article includes a plurality of display areas. Display areas adjacent to each other differ in at least one of an average hue, an average brightness and an average chroma and a first object to be displayed is formed by a combination of the plurality of display areas. At least one of the display areas includes a Fourier transform hologram configured to convert incident ray from a point light source or a laser light source into a second object to be displayed.

HPDLC material systems can be formulated in many different ways depending on the application. The HPDLC formulation can include a reactive monomer liquid crystal mixture (RMLCM). An RMLCM can include monomer acrylates, multi-functional acrylates, a cross-linking agent, a photo-initiator, and a liquid crystal (LC). The mixture (often referred to as syrup) frequently also includes a surfactant. One embodiment includes a reactive monomer liquid crystal mixture material including at least one liquid crystal, a photoinitiator dye, a coinitiators, and photopolymerizable monomers including at least one mono-functional monomer and at least one bi-functional monomer. In some embodiment, the bi-functional monomers accounts for at least 10 weight percent of the reactive monomer liquid crystal mixture material and the at least one mono-functional monomer accounts for at least 30 percent of the reactive monomer liquid crystal mixture material.

Manufacturing methods are disclosed to produce a seamless hologram using a free-form-lens enabling arbitrary adjustment of diffraction angle and also a thick hologram made of transparent inorganic materials and heat and UV resistant is disclosed.

The present disclosure refers to a method (200) for producing a laminated holographic display (100) comprising the following steps; providing (201) a display precursor (100-1), wherein the display precursor (100-1) comprises a first glass layer (113), a second glass layer (115), an unrecorded photopolymer film layer (117, 117-1), which is arranged between the first glass layer (113) and the second glass layer (115), and a polymer film layer (119), which is arranged between the unrecorded photopolymer film layer (117, 117-1) and the second glass layer (115), wherein the providing step (201) is performed in the absence of ambient light; laminating (203) the display precursor (100-1) to obtain a display laminate (100-2), wherein the laminating step (203) is performed in the absence of ambient light; and recording (205) a hologram (111) in the display laminate (100-2) by applying a light beam to the unrecorded photopolymer film layer (117, 117-1) of the display laminate (100-2) to obtain a recorded photopolymer film layer (117, 117-2) comprising the hologram (111), wherein the recording step (205) is performed in the absence of ambient light.