G03H2001/0447

Method for defect inspection of transparent substrate by integrating interference and wavefront recording to reconstruct defect complex images information

A method for defect inspection of a transparent substrate comprises (a) providing an optical system for performing a diffraction process of object wave passing through a transparent substrate, (b) interfering and wavefront recording for the diffracted object wave and a reference wave to reconstruct the defect complex images (including amplitude and phase) of the transparent substrate, (c) characteristics analyzing, features classifying and sieving for the defect complex images of the transparent substrate, and (d) creating defect complex images database based-on the defect complex images for comparison and detection of the defect complex images of the transparent substrate.

HOLOGRAPHIC IMAGING DEVICE AND METHOD
20210116863 · 2021-04-22 ·

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.

DIGITAL HOLOGRAPHIC IMAGING TECHNIQUE WITH TWIN IMAGE ELIMINATION
20230408977 · 2023-12-21 · ·

A digital holographic imaging technique, includes iterative steps of: a) through back-propagation to the object coordinate of a hologram field comprising a spatial distribution of amplitude corresponding to the spatial distribution of intensity of the hologram and a spatial distribution of phase, determining an object field involving a spatial distribution of absorption and of phase shift of the imaged object, b) thresholding the values of the spatial distribution of absorption and of phase shift by decreasing the values to below a respective threshold, the thresholds decreasing in each iteration, c) through repropagation of the object field to the hologram coordinate, determining a modified hologram field comprising a modified spatial distribution of amplitude and a modified spatial distribution of phase, d) replacing the spatial distribution of phase of the hologram field with the modified spatial distribution of phase, the spatial distribution of phase shift and of absorption of the imaged object being those of the object field of the last iteration.

PORTABLE DIFFRACTION-BASED IMAGING AND DIAGNOSTIC SYSTEMS AND METHODS
20210080390 · 2021-03-18 ·

The disclosure features systems and methods for measuring and diagnosing target constituents bound to labeling particles in a sample. The systems include a radiation source, a sample holder, a detector configured to obtain one or more diffraction patterns of the sample each including information corresponding to optical properties of sample constituents, and an electronic processor configured to, for each of the one or more diffraction patterns: (a) analyze the diffraction pattern to obtain amplitude information and phase information corresponding to the sample constituents; (b) identify one or more particle-bound target sample constituents based on at least one of the amplitude information and the phase information; and (c) determine an amount of at least one of the particle-bound target sample constituents in the sample based on at least one of the amplitude information and the phase information.

Analysis system including a confinement device with variable-size measurement chamber partially delimited by a flexible membrane

An analysis system features a confinement device, an optical measurement device, a flow device, a collecting conduit, and an actuation device. The confinement device comprises a measurement chamber, optically transparent first and second measurement surfaces that face each other across a distance that defines a thickness of the measurement chamber, and a flexible membrane that forms a seal with the measurement surfaces to laterally delimit the measurement chamber. When the collecting is sealed with a container, a connection is established that permits a liquid sample to be collected from the container. The optical measurement device emits light towards the chamber and detects light that has been transmitted through it, wherein the flow device causes liquid to flow through the collecting conduit between the container and the measurement chamber. The actuation device varies the thickness.

Interference optics for optical imaging device

A device includes a sensor, a coherent infrared illumination source and optics to direct an infrared reference beam to the sensor. The sensor is positioned to capture an image of an interference signal generated by an interference of the infrared reference beam and a wavelength-shifted exit signal. The wavelength-shifted exit signal propagates through the optics before interfering with the infrared reference beam.

Self-interference digital holographic system

A self-interference digital holographic system obtains interference patterns of incident light using a simple geometric phase lens, and obtains a holographic image of a target object using the interference patterns. The self-interference digital holographic is fabricated simply in a low cost and in a miniaturized size, and the use thereof as actual products is extended to a wide range of applications. The phase of incident light is be changed by rotating a polarizer, independently of a change in the optical path. Phase-shifting effects are obtained with fewer errors in all wavelength ranges, and a more accurate holographic image is produced. A single birefringence hologram is obtained by a one-time image-capturing process by simultaneously forming interference patterns from phase-shifted linearly-polarized beams by space division, using a phase shifter on the basis of space division. Moving holographic images can be captured.

IMAGE PROCESSING TECHNIQUES USING DIGITAL HOLOGRAPHIC MICROSCOPY

Digital holographic microscopy and related image processing techniques are described. A hologram captured in an image frame is split into different depths while a new hologram is being captured. Image slices of the hologram are determined and using free space impulse responses that are pre-calculated at a different precision than processing operations using the holographic data. Each computation is calculated in parallel based on the number of available processing cores and threads. The image slices are combined into a 2D array or 3D array to permit further processing of the combined array to count and size particles in the image frame. The reconstructed hologram is displayed at a subsequent image frame than that used to capture the hologram.

DEEP LEARNING-ENABLED PORTABLE IMAGING FLOW CYTOMETER FOR LABEL-FREE ANALYSIS OF WATER SAMPLES

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.

System, devices, and methods for digital holography

Systems, devices, and methods are described herein for performing digital holography to analyze dynamics of fluid flow. According to some aspects of this disclosure, a Digital Fresnel Reflection Holography (DFRH) system, which is arranged to utilize light backscattered from particles in a fluid chamber to create a hologram that may be processed to analyze characteristics of fluid flow. The DFRH system may utilize light reflected from an imaging window disposed between a light source and a sampling volume, to be analyzed as a reference wave, to form an interference pattern and resultant hologram. According to some aspects of this disclosure, the DFRH techniques may provide simple, cost-effective mechanisms with improved performance over other techniques for analyzing fluid flow using holography.