A beam steering method and device are provided. The beam steering method includes outputting, from a hologram recording medium on which a plurality of signal light beams having different steering information are recorded, signal light beam having specific steering information, by making reference light having a specific characteristic incident on the hologram recording medium. The method further includes o obtaining information about an object existing in the external environment based on the output signal light.

Some embodiments of the disclosure disclose a Three-Dimensional (3D) display device and method, wherein the device can include: a Light-Emitting Diode (LED) display, configured to display an image; a light path control structure including a multilayer pinhole type structure, configured to control emitting directions of light paths of the image to form 3D light field information, wherein multiple groups of pinhole arrays are arranged on each layer of the pinhole type structure; and a holographic function screen, configured to perform diffusion imaging on the 3D light field information to form a 3D image, wherein the LED display, the light path control structure and the holographic function screen are sequentially configured. According to some embodiments of the disclosure, the technical problems of the related art are solved.

A system for performing quantitative phase-contrast confocal microscopy includes a light source that emits light, a first beam splitter that splits the emitted light into an illumination path and a hologram path, means provided along the illumination path for delivering a first part of the emitted light to an object as a collimated line, a light sensor that captures light reflected off of the object to obtain an intensity image for the collimated line, and means provided along the hologram path for delivering a second part of the emitted light to the light sensor at an off-axis angle to obtain an off-axis hologram for the collimated line.

The present invention features VHOEs with expanded acceptance angle ranges as well as various systems and methods for fabricating VHOEs with expanded acceptance angle ranges. The VHOE with expanded acceptance angle range may include two or more individual Bragg gratings. In preferred embodiments, the two or more individual Bragg gratings have the same diffraction geometry but with shifted Bragg conditions. Having the same diffraction geometry means when light is incident on the VHOE including two or more individual Bragg gratings, the diffracted light from each of the Bragg gratings is co-linear or overlapping with the diffracted light from the other Bragg gratings. The Bragg condition for each of the Bragg gratings are shifted with respect to each neighboring Bragg grating by an amount up to the acceptance angle range of each individual Bragg grating.

Holograms are generated using a rotatable transparent cylinder and a coherent light source placed inside or outside of such cylinder to record a hologram in a photosensitive film having a reflective film on one side. Recording is done in continuous mode while cylinder is rotating and photosensitive film is translating underneath in contact with cylinder due to friction forces provided by a layer of sticky polymer.

Described is a holographic film (100) whose transmission and/or reflection properties vary periodically along at least one of its directions of principal extent, said film being designed for at least partial transmission (22, 28) of light (20, 26) of at least one first wavelength range that is irradiated from a multiplicity of periodically disposed illuminants (200) and that impinges on the holographic film (100). Also described are a lighting means (300), a backlighting means and a method for producing a holographic film (100).

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 substantially constant reflective axes across a relatively wide range of wavelengths. In some examples, a skew mirror has substantially constant reflective axes across a relatively wide range of angles of incidence. Exemplary methods for making and using skew mirrors are also disclosed. Skew mirrors include a grating structure, which in some examples comprises a hologram.

Apparatus and methods for coherent diffractive imaging with arbitrary angle of illumination incidence utilize a method of fast remapping of a detected diffraction intensity pattern from a detector pixel array (initial grid) to a uniform spatial frequency grid (final grid) chosen to allow for FFT on the remapped pattern. This is accomplished by remapping the initial grid to an intermediate grid chosen to result in a final grid that is linear in spatial frequency. The initial grid is remapped (generally by interpolation) to the intermediate grid that is calculated to correspond to the final grid. In general, the initial grid (x,y) is uniform in space, the intermediate grid ({tilde over (x)},{tilde over (y)}) is non-uniform in spatial frequency, and the final grid ({tilde over (f)}.sub.x,{tilde over (f)}.sub.y) is uniform in spatial frequency.

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 substantially constant reflective axes across a relatively wide range of wavelengths. In some examples, a skew mirror has substantially constant reflective axes across a relatively wide range of angles of incidence. Exemplary methods for making and using skew mirrors are also disclosed. Skew mirrors include a grating structure, which in some examples comprises a hologram.

A surface relief structure includes a recording medium configured to be structurally modified when exposed to interfering and non-interfering portions of radiation beams, the structurally modified recording medium including, when viewed in a two-dimensional cross-section along one of the axes of the recording medium a plurality of equally spaced steps of fine-sized periodicity superimposed upon a plurality of deep depressions of substantially coarse-sized periodicity. The structurally modified recording medium is configured to produce in reflection single and multiple colors in a broad spectral range when illuminated by a source of light.