A focus modulation optical system and a holographic display device having the focus modulation optical system are disclosed. The holographic display device includes a light source configured to emit a plurality of color lights, a focus modulation optical system including at least one variable focus lens that is configured to change a focusing position of incident light by electrical control of the at least one variable focus lens based on a color of light incident on the variable focus lens, and a spatial light modulator configured to form a holographic image by diffracting light output from the focus modulation optical system.

The present invention relates to an arrangement for the generation of images of optical sections of a three-dimensional (3D) volume in space such as an object, scene, or target, comprising: an illumination unit, an optical arrangement for the imaging of the object onto at least one spatially resolving detector, a scanning mechanism for scanning the entire object and a signal processing unit for the implementation of a method for digital reconstruction of a three-dimensional representation of the object from images of said object as obtained by said detector (which may be in a form of a hologram), wherein the optical arrangement includes a diffractive optical element (herein a phase pinhole), realized using a Spatial Light Modulator (SLM) configured to mimic an actual physical pinhole, while allowing the formation of a three-dimensional representation for a specific point of interest in said object, such that for each scanning position a single hologram or an image is recorded.

In an embodiment, an off-axis hologram is provided. The off-axis hologram creates two, conjugate images which are on either side (off-axis) of the 0-order beam. A Multiple Beam Grating (MBG) is used to both duplicate the conjugate images and to redirect the images along the axis. The 0-order beam is blocked before or at the MBG. The MBG projects the images onto a 3D surface, such as a person's face.

The embodiments of the present invention provide a display system and a display method. The display system includes a projection unit and an eye tracking unit. The projection unit includes a projection light source, a projection lens and a spatial light modulator. The projection lens is located between the projection light source and the spatial light modulator. In a direction of an optical axis of the projection lens, the projection lens includes a first lens portion overlapping with the spatial light modulator and a second lens portion not overlapping with the spatial light modulator. The eye tracking unit includes a camera. An imaging optical path of the camera passes through the second lens portion. The display system and the display method provided by the embodiments of the present invention can be advantageously used in the display field including holographic display, simplifying the optical design, and providing a compact and efficient optical system.

The inventors have discovered a method to improve image quality in holography and, for the first time, utilize lenses made from birefringent materials to advantageously split an incoming beam of either coherent or incoherent light into two coincident beams with different focal lengths that interfere with one another and thus create holograms free of electro-optical or pixelated devices. This discovery has many advantages over current methods to create holograms in which many components, including multiple lenses, other electro-optical devices, and/or beam paths are necessary to create holograms. The current invention provides a purely optical holographic process which has better performance and holographic simplicity, in addition to being able to miniaturize holographic processes more than is currently possible in state of the art holography systems.

A method for replicating a holographic optical element and a holographic optical element replicated thereby are provided. The holographic optical element is larger than a master. The master has a holographic grating pattern generated on the master by interference of the reflected, diffracted or transmitted beam generated by irradiating the master having a specific diffraction grating pattern formed thereon with a laser beam.

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 illumination apparatus using a coherent light source, comprising: a coherent light source that generates a coherent light beam, a microlens array including a collection of a large number of independent lenses; and a light beam scanning device that irradiates the light beam onto the microlens array and carries out scanning so that an irradiation position and an irradiation direction of the light beam on the microlens array changes with time. Each of the independent lenses included in the microlens array has a function of refracting light irradiated from the light beam scanning device and forming an irradiation region on a light receiving surface. The light receiving surface is not a refractive element, and is configured so that irradiation regions formed by the independent lenses become substantially a same common region on the light receiving surface. The irradiation regions being irradiated by light which is refracted by the independent lenses.

There is provided a lighting device arranged to produce a controllable light beam for illuminating a scene. The device comprises an addressable spatial light modulator arranged to provide a selectable phase delay distribution to a beam of incident light. The device further comprises Fourier optics arranged to receive phase-modulated light from the spatial light modulator and form a light distribution. The device further comprises projection optics arranged to project the light distribution to form a pattern of illumination as said controllable light beam.

A photopolymer composition comprising a polymer matrix or a precursor thereof including a reaction product between (i) a (meth)acrylate-based (co)polymer in which a silane-based functional group is located in a branched chain and an equivalent weight of the silane-based functional group is 300 g/eq to 2000 g/eq, and (ii) a linear silane crosslinking agent; a photoreactive monomer; and a photoinitiator, a hologram recording medium using the same, an optical element using the hologram recording medium, and a holographic recording method. The photopolymer composition can more easily provide a photopolymer layer having improved durability against temperature and humidity while having a large refractive index modulation value.