Embodiments described herein relate to a large area lens-free imaging device. One example is a lens-free device for imaging one or more objects. The lens-free device includes a light source positioned for illuminating at least one object. The lens-free device also includes a detector positioned for recording interference patterns of the illuminated at least one object. The light source includes a plurality of light emitters that are positioned and configured to create a controlled light wavefront for performing lens-free imaging.

A method of producing information from at least one camera image of an object, including: A) recording raw image data of the at least one camera image, B) evaluating the raw image data by a mathematical linkage to produce combination image data, C) deriving the information from the combination image data, D) outputting the information, E) determining an actual measure for a data quality of the raw image data prior to or after evaluation steps in step B), F) determining a deviation between the actual measure for the data quality and a target measure for the data quality of the raw image data of at least one camera image, and G) again recording all raw image data of those camera images, for which the deviation determined in step F) is greater than a predetermined threshold value and repeating at least one evaluation step from step B) and steps C) to F) either until the deviation determined in step F) for the raw image data of all camera images from the plurality of camera images is less than the threshold value or until a predetermined termination condition is fulfilled.

Holographic volume gratings in waveguide cells can be recorded using many different methods and systems in accordance with various embodiments of the invention. One embodiment includes a holographic recording system including at least one laser source configured to emit recording beams and a movable platform configured to move between a first position and a second position, wherein when the movable platform is in the first position, the at least one laser source is configured to emit a first set of one or more recording beams toward a first set of one or more stations and when the movable platform is in the second position, the at least one laser source is configured to emit a second set of one or more recording beams toward a second set of one or more stations.

There is herein defined optics (e.g. an array of optics) forming an optical beam to either produce a collimated or diverging/converging beam emerging from a virtual source point to illuminate a hologram. There is also described an optical beam illuminating a reflection hologram from the front and a further configuration where an optical beam combined with a holographic optical element (HOE) minor enables rear illumination of a reflection hologram.

A grating coupler may be fabricated by exposing a photopolymer layer to grating forming light for forming periodic refractive index variations in the photopolymer layer. The photopolymer layer may be exposed to apodization light for reducing an amplitude of the periodic refractive index variations in a spatially-selective manner. The apodization may also be achieved or facilitated by subjecting outer surface(s) of the photopolymer layer to a chemically reactive agent that causes the refractive index contrast to be reduced near the surface(s) of application. The apodized refractive index profile of the gratings facilitates the reduction of optical crosstalk between different gratings of the grating coupler.

An imaging flow cytometer device includes a housing holding a multi-color illumination source configured for pulsed or continuous wave operation. A microfluidic channel is disposed in the housing and is fluidically coupled to a source of fluid containing objects that flow through the microfluidic channel. A color image sensor is disposed adjacent to the microfluidic channel and receives light from the illumination source that passes through the microfluidic channel. The image sensor captures image frames containing raw hologram images of the moving objects passing through the microfluidic channel. The image frames are subject to image processing to reconstruct phase and/or intensity images of the moving objects for each color. The reconstructed phase and/or intensity images are then input to a trained deep neural network that outputs a phase recovered image of the moving objects. The trained deep neural network may also be trained to classify object types.

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.

A holographic imaging device is disclosed. In one aspect, the holographic imaging device comprises an imaging unit comprising at least two light sources, wherein the imaging unit is configured to illuminate an object by emitting at least two light beams with the at least two light sources. A first and second light beams have different wave-vectors and wavelengths. The holographic imaging device further comprises a processing unit configured to obtain at least two holograms of the object by controlling the imaging unit to sequentially illuminate the object with respectively the first light beam and the second light beam, construct at least two 2D image slices based on the at least two holograms, wherein each 2D image slice is constructed at a determined depth within the object volume, and generate a three-dimensional image of the object based on a combination of the 2D image slices.

A method for producing a holographic optical element. The method includes a step of exposing a recording material to a phase pattern which is provided by a first modulated light beam with a first phase portion. Furthermore, the method includes a step of an additional exposure of the recording material to the phase pattern, which is provided by a second modulated light beam with a second phase portion, wherein the second phase portion has a phase offset with respect to the first phase portion in order to produce a holographic optical element.

The invention relates to a free-beam interferometric method for illuminating a sequence of sectional areas in the interior of the light-scattering object. The method makes it possible for the user to select a larger image field and/or a higher image resolution than previously possible with the occurrence of self-interference of the specimen light from a scattering specimen.