G03H2001/045

System and method for phase retrieval in lensless imaging

A method and system for use in reconstruction and retrieval of phase information associated with a two-dimensional diffractive response are presented. The method comprising: providing (75) input data indicative of one or more diffractive patterns corresponding to diffractive responses from one or more objects (50). Dividing (130) said input data into a plurality of one-dimensional slices and determining (140) one-dimensional phase data for at least some of said one-dimensional slices. Tailoring (150) the reconstructed phase data of said one-dimensional slices to form a two-dimensional phase solution. The two-dimensional phase solution is defined by phase shifts of said reconstructed one-dimensional phase data of said one-dimensional slices. The two-dimensional phase solution thus enables obtaining two-dimensional reconstructed phase data suitable for reconstruction of image data (250).

APPARATUS FOR MANUFACTURING HOLOGRAPHIC OPTICAL ELEMENT, AND APPARATUS FOR RECONSTRUCTING HOLOGRAMS

An apparatus for manufacturing a hologram includes a holographic optical element on which a first interference pattern of a first signal beam and a first reference beam is recorded and a second interference pattern of a second signal beam modulated by a Fourier lens and a second reference beam is recorded. Also, an apparatus for reconstructing a hologram by using the holographic optical element is provided.

Display System
20180120768 · 2018-05-03 ·

A display system comprising a first plurality of pixels, a second plurality of pixels, a first Fourier transform lens and a second Fourier transform lens. The first plurality of pixels is arranged to display first holographic data corresponding to a first holographic reconstruction and receive light of a first wavelength. The a second plurality of pixels is arranged to display second holographic data corresponding to a second holographic reconstruction and receive light of a second wavelength. The first Fourier transform lens is arranged to receive spatially modulated light having a first wavelength from the first plurality of pixels and perform an optical Fourier transform of the received light to form the first holographic reconstruction at a replay plane, wherein the first holographic reconstruction is formed of light at the first wavelength. The second Fourier transform lens is arranged to receive spatially modulated light having a second wavelength from the second plurality of pixels and perform an optical Fourier transform of the received light to form the second holographic reconstruction at the replay plane, wherein the second holographic reconstruction is formed of light at the second wavelength. The optical path length from the first Fourier transform lens to the replay plane is not equal to the optical path length from the second Fourier transform lens to the replay plane.

Dosimeters including lensless imaging systems
09952417 · 2018-04-24 · ·

Among other things, a method comprises imaging a sample displaced between a sensor surface and a surface of a microscopy sample chamber to produce an image of at least a part of the sample. The image is produced using lensless optical microscopy, and the sample contains at least blood from a subject. The method also comprises automatically differentiating cells of different types in the image, generating a count of one or more cell types based on the automatic differentiation, and deriving a radiation dose the subject has absorbed based on the count.

Dosimeters including lensless imaging systems
09910254 · 2018-03-06 · ·

Among other things, a method comprises imaging a sample displaced between a sensor surface and a surface of a microscopy sample chamber to produce an image of at least a part of the sample. The image is produced using lensless optical microscopy, and the sample contains at least blood from a subject. The method also comprises automatically differentiating cells of different types in the image, generating a count of one or more cell types based on the automatic differentiation, and deriving a radiation dose the subject has absorbed based on the count.

Coherent diffractive imaging with arbitrary angle of incidence

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.

OPTICAL SYSTEM PHASE ACQUISITION METHOD AND OPTICAL SYSTEM EVALUATION METHOD

When an optical system is illuminated with illumination light fluxes emitted from respective input image points, an interference image generated by superimposing output light fluxes output from the optical system and a reference light flux coherent with the output light fluxes is imaged to acquire interference image data collectively including information of an interference image about all input image points. Diffractive optical light propagation simulation is performed to acquire a phase distribution associated with only light emitted from a single input image point at a position where reconstructed light fluxes to the respective output light fluxes are separated into each light flux. In each input image point, this simulation is performed to acquire a phase distribution on an exit pupil plane.

HOLOGRAPHIC WAVEFRONT PRINTING SYSTEM AND METHOD

A holographic wavefront printing system and method are provided. A two-dimension digital blazed grating is loaded on a phase hologram, and the emergent direction of active region diffracted light is adjusted to prevent overlapping with the dead region diffracted light after being Fourier transformed by a lens, and a phase spatial light modulator is inclined by a preset angle to change the emergent direction of the diffracted light, such that the dead region zeroth-order and first-order diffracted light on a focusing surface are symmetrical with respect to a main optical axis of a first lens, the frequency spectrum center of active region zeroth-order diffracted light is then loaded to the original frequency spectrum center without information change. In this way, the adverse effects of the dead region diffracted light and active region high-order diffracted light of the phase spatial light modulator on holographic wavefront printing are eliminated.

Holographic wavefront printing system and method

A holographic wavefront printing system and method are provided. A two-dimension digital blazed grating is loaded on a phase hologram, and the emergent direction of active region diffracted light is adjusted to prevent overlapping with the dead region diffracted light after being Fourier transformed by a lens, and a phase spatial light modulator is inclined by a preset angle to change the emergent direction of the diffracted light, such that the dead region zeroth-order and first-order diffracted light on a focusing surface are symmetrical with respect to a main optical axis of a first lens, the frequency spectrum center of active region zeroth-order diffracted light is then loaded to the original frequency spectrum center without information change. In this way, the adverse effects of the dead region diffracted light and active region high-order diffracted light of the phase spatial light modulator on holographic wavefront printing are eliminated.

DIGITAL HOLOGRAPHIC METHOD OF MEASURING CELLULAR ACTIVITY AND MEASURING APPARATUS WITH IMPROVED STABILITY
20170131682 · 2017-05-11 ·

Motility contrast imaging (MCI) is a depth-resolved holographic technique to extract cellular and subcellular motion inside tissue. The holographic basis of the measurement technique makes it highly susceptible to mechanical motion. The motility contrast application, in particular, preferably includes increased mechanical stability because the signal is based on time-varying changes caused by cellular motion, which should not be confused with mechanical motion of the system. Apparatus for motility contrast imaging that provides increased mechanical stability are disclosed. It is based on common-path configurations, in which the signal and reference beams share optical elements in their paths to the detector. The two beams share mechanical motions in common, and hence those motions do not contribute to the signal.