A method of manufacturing a holographic element used in a projection device is provided. The projection device has a light source configured to emit light conforming to a non-uniform light intensity distribution function. The method includes: multiplying the non-uniform light intensity distribution function by a diffraction intensity and angle function of a grating to obtain a product function; determining whether the product function is substantially equal to 1 in a predetermined range of angle or wavelength; if the the determination result is yes, determining a pair of incident angles respectively of a reference beam and a signal beam according to the diffraction intensity and angle function; and recording a holographic material with the reference beam and the signal beam respectively at the pair of incident angles, so as to manufacture a holographic element with the grating therein.

The invention relates to an illumination device for illuminating at least one light modulator system of a liquid crystal display, the device comprising at least one waveguide substrate for guiding at least one targeted light beam that can be coupled into the waveguide substrate. The waveguide substrate is at least in optical contact with at least one holographic optical decoupling substrate comprising a plurality of decoupling regions and a decoupling region is at least designed to decouple part of the targeted light beam in the form of a plurality of sub-beams in the direction of the light modulator system. At least one diffuser module is provided, said diffuser module being designed in such a way that at least the outermost sub-beams of two neighboring decoupling regions are at least adjacent to one another before exiting the diffuser module.

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 behaviour of the recording stack during the irradiating step.

The invention relates to a method for recording a plurality of scatter volume holograms in a photopolymeric recording medium, the method comprising at least the following steps providing a first laser light source, providing a photopolymeric recording medium comprising a substrate and a photoactive layer, wherein the photopolymeric recording medium has an index modulation n of at least 0.04 and a thickness d of the photoactive layer of at least 25 m, irradiating the photopolymeric recording medium with the first laser light beam generated by the first laser light source with a minimum irradiation energy dosage of 3*D.sub.i, D.sub.i; being the inhibition dosage of the photoactive layer, wherein the irradiation of the photopolymeric recording medium is performed such that the light of the irradiating first laser light beam is scattered at scattering centers, the scattering centers being generated by the chemical react ion in the photoactive layer induced by the first laser light beam thus forming a plurality of scatter volume holo grams by interaction between the irradiating first laser light beam and the scattered light of the first laser light beam.

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.

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.

Various holographic films for recording multicolor volume holograms, especially full color volume reflection holograms, and to manufacturing techniques for such film, and to corresponding methods of recording multicolor and full-color volume, in particular volume reflection holograms. We describe a holographic film for recording a multicolor volume hologram, the film including: a carrier; a first photosensitive recording layer sensitive to one or both of red and green laser light; and a second photosensitive recording layer sensitive to blue laser light. Both the first and second photosensitive recording layers include silver halide and have a grain size of less than 30 nm, and at least one of the photosensitive recording layers has a thickness of greater than 3 ?m and less than 5 ?m.

A device for continuously replicating a hologram has a coating module to coat a liquid photopolymer onto a first carrier film, a lamination module to apply a second carrier film to the first carrier film coated with the photopolymer to obtain a photopolymer composite including a liquid photopolymer layer between two carrier films, an exposure module having a light source, and a master element with a master hologram to be replicated, and a fixing module to cure the replicated hologram in the photopolymer composite. The master element is axially rotatably mounted, and the exposure module is designed to bring the photopolymer composite in optical contact with the master element, while the light source exposes the master hologram to obtain a replicated hologram in a region of the photopolymer composite.