A holographic storage optical system includes a storage medium, a recording unit, an imaging unit and a servo unit. The recording unit comprises a movable Fourier lens, by which the positions and irradiation angles of a signal light spot and a reference light spot are adjusted. The servo unit comprises a calibration lens for adjusting the positions of a servo light spot in the horizontal and vertical directions so that the servo light spot is located at an optimal position relative to signal light beam and reference light beam. The beam calibrating method comprises (1) before recording a data hologram, burning a calibration hologram at a calibration holographic positioning mark on an optical track of a storage medium; (2) before reproducing the data hologram, using the calibration hologram to optimize the signal-to-noise ratio of the hologram reproduced by adjusting the calibration lens and the Fourier lens.

A method and systems for simultaneous recording of superimposed holographic gratings for augmented reality devices are provided. The method includes: generating a beam by a single light source, directing the beam to a decoherence unit at a predetermined angle, forming at least two recording beams by the decoherence unit by splitting the beam, forming at least two recording channels in the decoherence unit to transmit the at least two recording beams and output them from the decoherence unit, output angles of each of the at least two recording beams being different, the at least two recording beams being non-interfering when leaving the decoherence unit, which is provided in accordance with at least one of: output times, spatial positions, polarization states, or spectral compositions of each of the at least two recording beams, illuminating a recording material layer and one master diffractive optical element/master holographic optical element (master DOE/HOE) comprising at least one preliminary formed diffraction/holographic grating by the at least two non-interfering recording beams, simultaneously forming at least two superimposed holographic gratings from the master DOE/HOE on or in the recording material layer, the formed superimposed holographic gratings having a same surface period, but a different spatial period.

Embodiments of the present disclosure provide an imaging device for holographic imaging of a sample, the imaging device comprising a light source generating a light beam, a beam splitter splitting the light beam into an object beam along an object beam path and a reference beam along a reference beam path, and a detector. The imaging device defines a sample position. The object beam is propagated through the sample position, and the detector is arranged to prevent non-scattered object light, passing through the sample position without being scattered by the sample, from being incident onto the detector. The reference beam is propagated through the sample position, and the detector is arranged so that non-scattered reference light, passing through the sample position without being scattered by the sample, is incident onto the detector. The detector detects an interference pattern formed by scattered object light and the non-scattered reference light.

The layered generation of at least one volume grating in a recording medium by way of exposure, the recording medium having at least one photosensitive layer which is sensitized for a presettable wavelength of the exposure light. Each volume grating is generated in the recording medium by at least two wave fronts of coherent light capable of generating interference, the wave fronts being superposed in the recording medium at a presettable depth, at a presettable angle and with a presettable interference contrast. The depth and the thickness of the refractive index modulation and/or transparency modulation of a volume grating in the recording medium is controlled by depth-specific control of the spatial and/or temporal degree of coherence of the interfering wave fronts in the direction of light propagation.

A polarization holographic microscope system is disclosed. The polarization holographic microscope system can acquire a birefringence image and a three-dimensional phase image with high sensitivity by aperture synthesis of sample beams at various angles, and a sample image acquisition method using the microscope system.

Example embodiments relate to imaging devices for in-line holographic imaging of objects. One embodiment includes an imaging device for in-line holographic imaging of an object. The imaging device includes a set of light sources configured to output light in confined illumination cones. The imaging device also includes an image sensor that includes a set of light-detecting elements. The set of light sources are configured to output light such that the confined illumination cones are arranged side-by-side and illuminate a specific part of the object. The image sensor is arranged such that the light-detecting elements detect a plurality of interference patterns. Each interference pattern is formed by diffracted light from the object originating from a single light source and undiffracted light from the same single light source. At least a subset of the set of light-detecting elements is arranged to detect light relating to not more than one interference pattern.

A method for producing a computer-generated hologram including producing a reference beam, producing an object beam, applying computer-generated information regarding the hologram to the object beam, overlapping the object beam and the reference beam on or in a light-sensitive recording medium in order to apply the hologram by exposure, wherein several portions of the light-sensitive recording medium are exposed, one after the other, to the object beam and the reference beam simultaneously in order to produce a plurality of sub-holograms, wherein the angle of incidence at which the reference beam hits the surface of a first portion of the recording medium is different from the angle of incidence at which the reference beam hits the surface of a second portion of the recording medium. A change in the angle of incidence of the reference beam is achieved by changing the point of incidence of the reference beam on a lens.

A dark field digital holographic microscope and associated metrology method is disclosed which is configured to determine a characteristic of interest of a structure. The dark field digital holographic microscope includes an illumination branch for providing illumination radiation to illuminate the structure; a detection arrangement for capturing object radiation resulting from diffraction of the illumination radiation by the structure; and a reference branch for providing reference radiation for interfering with the object radiation to obtain an image of an interference pattern formed by the illumination radiation and reference radiation. The reference branch has an optical element operable to vary a characteristic of the reference radiation so as to reduce and/or minimize variation in a contrast metric of the image within a field of view of the dark field digital holographic microscope at a detector plane.

A deflection optical element, which diffracts incident light, includes a substrate having translucency, and a holographic material layer disposed so as to overlap the substrate, the holographic material layer being formed with a diffraction grating composed of interference fringes, wherein the holographic material layer is formed with an alignment mark where the interference fringes are discontinuous, and the alignment mark is located in an optically effective area where the holographic material layer diffracts the incident light.

A polarization holographic microscope system is disclosed. The polarization holographic microscope system can acquire a birefringence image and a three-dimensional phase image with high sensitivity by aperture synthesis of sample beams at various angles, and a sample image acquisition method using the microscope system.