A holographic recording system includes a linear translation stage configured to position a holographic material layer, a light source configured to emit a laser beam, a beam splitting subsystem configured to split the laser beam into a first light beam and a second light beam and direct the second light beam towards the holographic material layer, a spatial-light modulator configured to implement a fringe pattern that modulates the first light beam to generate an object beam, a filter configured to filter the object beam, a demagnification optical subsystem configured to demagnify the object beam, and a switchable grating stack configurable to direct the object beam to a set of directions towards the holographic material layer to interfere with the second light beam. In some embodiments, the switchable grating stack includes a plurality of polarization gratings and/or a plurality of switchable waveplates arranged in a stack.

A method for producing a holographic optical element (HOE) that is provided for projection in a projection system. A hologram is recorded by the fact that a first Gaussian beam and a second Gaussian beam are caused to interfere on a holographic film for at least two different configurations. The first Gaussian beam is a reference beam that, for the at least two different configurations, is identical to a reconstruction beam with which the HOE is reconstructed. The second Gaussian beam is furthermore an object beam that, upon reconstruction of the HOE utilizing the reconstruction beam, is identical to a projection beam that is used in the projection system for projection. For the at least two different configurations, at least one beam property that depends respectively on predefined projection properties of the projection system is predefined for the second Gaussian beam.

An apparatus for producing an optically variable film includes a laser configured to emit a beam, a telescoping lens section having a first lens and a second lens spaced apart by a first distance and an interferometer configured to direct the beam toward a workpiece. The laser may be operated at a predetermined power level and the first and second lenses are sized and spaced relative to one another to direct the beam onto the workpiece at about 200-230 dots per inch. The workpiece may include a polyethylene terephthalate (PET) layer configured to be ablated by the beam, forming a microstructure in the surface of the layer. The microstructure may be randomized and used to present non-chroma visual effects.

A system includes a diffractive optical element configured to receive a first beam and a second beam interfering with one another to generate a first interference pattern. The diffractive optical element is also configured to forwardly diffract the first beam and the second beam to output a third beam and a fourth beam. The third beam and the fourth beam interfere with one another to generate a second interference pattern. The system also includes a detector configured to detect the second interference pattern.

A device includes a display configured to generate an image light. The device also includes a waveguide optically coupled with the display and configured to guide the image light to an exit pupil of the device. The waveguide includes a grating including a birefringent material, and a birefringence of the grating is configured to increase along a pupil-expanding direction of the device.

A method of manufacturing a Volume Bragg Grating (VBG) is provided, comprising providing a cylindrical bulk medium made of a transparent glass material and having a central axis along a longitudinal direction, and inscribing an interference pattern in the cylindrical bulk medium. The interference pattern has a plurality of grating fringe elements distributed along a line parallel to the central axis. The method further includes rotating the cylindrical bulk medium about the central axis during said inscribing, thereby azimuthally extending the grating fringes elements. There is further provided a VBG manufactured according to such a method, the use of such a VBG in a CPA system of cladding-pumped fiber laser.

An optical reflective device referred to as a skew mirror, having a reflective axis that need not be constrained to surface normal, is described. Examples of skew mirrors are configured to reflect light about a constant reflective axis across a relatively wide range of wavelengths. In some examples, a skew mirror has a constant reflective axis across a relatively wide range of angles of incidence. Exemplary methods for making and using skew minors are also disclosed. Skew mirrors include a grating structure, which in some examples comprises a hologram.

A method of manufacturing a holographic optical element, including: irradiating a first surface of a photosensitive substrate with a first layer, and irradiating a second surface of the photosensitive substrate with a second laser. The light emitted by the first laser is spread in an irradiation direction and the light emitted by the second laser is collected in the irradiation direction to form a plurality of groups and a plurality of overlapping angles formed by a progress direction of the light emitted by the first laser and the progress direction of the light emitted by the second laser at a predetermined location of a photosensitive area, and each of the plurality of the overlapping angles are different from each other. A display device including the holographic optical element measured using this method.

Direct pixel-by-pixel phase engineering in a SLM is an effective method for the holographic fabrication of graded photonic super-quasi-crystals with desired disorder and graded photonic super-crystals with rectangular unit-cells. Multiple levels of filling fractions of dielectric in the crystal have been created in the graded regions. Fabrication of these graded photonic super-crystals and super-quasi-crystals with small feature size is possible, using a laser projection system consisting of integrated spatial light modulator and reflective optical element.

A copying device for generating a replication hologram that represents a copy of a master hologram. The device includes an object hologram for generating an object wave via a master signal, and a reference hologram for generating a reference wave with the aid of the master signal.