162 results about "Phase imaging" patented technology

An optical microscope is provided with an adjustable optical phase ring. The adjustable ring provides a way to compensate for distortion in the visible phase ring before the light reaches the sample. In an inverted microscope, when observing transparent cells under a liquid, the visible light phase ring is distorted. By the use of a Liquid Crystal Display (LCD) in place of a fixed ring, the projected ring is adjusted to realign the light and produce phase. In a typical micro plate, the meniscus formed produces a lens effect that is realigned by providing changes in the position and pattern, to allow phase imaging over a wider portion of the well. The realignment of the ring can be manual or automated and can be dynamically adjusted based upon an observed image of the sample.

Phase sensitive X-ray imaging methods can provide substantially increased contrast over conventional absorption based imaging, and therefore new and otherwise inaccessible information. The use of gratings as optical elements in hard X-ray phase imaging overcomes some of the problems that have impaired the wider use of phase contrast in X-ray radiography and tomography. So far, to separate the phase information from other contributions detected with a grating interferometer, a phase-stepping approach has been considered, which implies the acquisition of multiple radiographic projections. Here,an innovative, highly sensitive X-ray tomographic phase contrast imaging approach is presented based on grating interferometry, which extracts the phase contrast signal without the need of phase stepping. Compared to the existing phase step approach, the main advantage of this new method dubbed 'reverse projection' is the significantly reduced delivered dose, without degradation of the image quality. The new technique sets the pre-requisites for future fast and low dose phase contrast imaging methods, fundamental for imaging biological specimens and in-vivo studies.

Hilbert phase microscopy (HPM) as an optical technique for measuring high transverse resolution quantitative phase images associated with optically transparent objects. Due to its single-shot nature, HPM is suitable for investigating rapid phenomena that take place in transparent structures such as biological cells. A preferred embodiment is used for measuring biological systems including measurements on red blood cells, while its ability to quantify dynamic processes on the millisecond scale, for example, can be illustrated with measurements on evaporating micron-size water droplets.

A method and apparatus for using deep learning in label-free cell classification and machine vision extraction of particles. A time stretch quantitative phase imaging (TS-QPI) system is described which provides high-throughput quantitative imaging, and utilizing photonic time stretching. In at least one embodiment, TS-QPI is integrated with deep learning to achieve record high accuracies in label-free cell classification. The system captures quantitative optical phase and intensity images and extracts multiple biophysical features of individual cells. These biophysical measurements form a hyperdimensional feature space in which supervised learning is performed for cell classification. The system is particularly well suited for data-driven phenotypic diagnosis and improved understanding of heterogeneous gene expression in cells.

New methods for phase contrast imaging in transmission electron microscopy use the imaging electron beam itself to prepare a hole-free thin film for use as an effective phase plate, in some cases eliminating the need for ex-situ fabrication of a hole and reducing requirements for the precision of the ZPP hardware. The electron optical properties of the ZPP hardware are modified primarily in two ways: by boring a hole using the electron beam; and/or by modifying the electro-optical properties by charging induced by the primary beam. Furthermore a method where the sample is focused by a lens downstream from the ZPP hardware is disclosed. A method for transferring a back focal plane of the objective lens to a selected area aperture plane and any plane conjugated with the back focal plane of the objective lens is also provided.

The invention discloses a transmission type sample amplitude and phase imaging device and a transmission type sample amplitude and phase imaging method. A small-aperture diaphragm is moved for scanning, diffraction spots of the small-aperture diaphragm at certain distances are used as light for illuminating a sample, the diffraction spots of the small-aperture diaphragm at different positions are recorded by using a detector in an image plane of the small-aperture diaphragm in an imaging system, and a complex amplitude transmittance function of the sample is obtained through a computer in an iterative operation way, so that amplitude information can be obtained, and phase imaging can be realized. In addition, by each diffraction pattern, the light intensity distribution of the diffraction spots can be recorded, and the actual position, which corresponds to the light intensity distribution, of the small-aperture diaphragm can be obtained through relevancy operation to realize translation stage accuracy-independent reproductive image reconstruction, so that errors caused by the low accuracy of a translation stage are eliminated.

The invention discloses an interferometric phase microscopy one-step imaging system and method based on two-step phase shift, and adopts the technical scheme that based on a typical Mach-Zehnder interference light path, lateral displacement beam splitting mirrors are adopted to perform light splitting on sample light and reference light respectively, a wave plate is utilized as a phase shifter, and two interference figures can be acquired at the same time through single exposure, and phase imaging can be realized quickly through corresponding phase recovery operation, and a spatial form structure of a phase body is further deconstructed. The interferometric phase microscopy one-step imaging system and method are suitable for all interferometric phase microscopy imaging systems, such as traditional coaxial interference, off-axis interference and slight off-axis interference, and have high practical value and wide application prospect in the aspect of phase microscopy, particularly in the field of application and identification of biological cell morphology.

Systems and methods for quantitative phase imaging are disclosed. In one embodiment, a method includes acquiring a through-focal series of defocused images of an object illuminated with a partially coherent light source; calculating a plurality of estimates of longitudinal intensity derivatives for respective fittings of the series of defocused images; recovering a phase estimate for each respective estimate of the longitudinal intensity derivative by solving a transport of intensity (TIE) equation; filtering the recovered phase estimates to produce component parts of an overall phase estimate; and forming an overall phase image by addition of the filtered phase estimates.

A phase grating used for X-ray phase imaging is provided, in which a pitch can be narrowed by using a diffraction grating with a low aspect ratio. A phase grating used for X-ray phase imaging, characterized in that the phase grating includes a first diffraction grating in which a first projection part whose thickness is formed so that an in-coming X-ray transmits with a phase π-shifted, and a first aperture part with the same aperture width as a width of the first projection part are cyclically arranged, and a second diffraction grating in which a second projection part with the same width as a width of the first projection part, and a second aperture part with the same aperture width as the aperture width of the first aperture part are cyclically arranged, and the second diffraction grating is formed as displaced on the first diffraction grating.

The invention discloses a two-step diffraction phase imaging method and a corresponding phase retrieval method. 0 scale diffracted by raster is adopted to form two-step geometric optical path interference patterns with high stability with +1 scale and -1 scale diffraction light in sequence; then the difference between the two interference patterns are calculated to eliminate background light intensity so as to apply Hilbert transform to retrieve phase information of samples. Compared with frequently-used phase retrieval methods of off-axis interference, high-pass filtering is not needed in the methods, high-frequency information is reserved integrally, the phase retrieval speed is high and the two-step diffraction imaging method is applicable to all off-axis interferences including slight off-axis interference. The two-step diffraction phase imaging method and the corresponding phase retrieval method have a wide utility value and an application prospect in phase microscopy, especially in the application field of transparent samples such as biological cell phase imaging and phase measuring.

The coherent imaging method of 4f position based on the Michelson's interferometer is the nonlinear refractive method of 4f position coherent imaging measuring medium based on the Michelson's interferometer. It can solves the problem of data treating bother, nonlinear absorption of traditional 4f coherent imaging technology and the small deform range, high request for stability and complex data treating of Mach-Zehnder interference. The method is composed of the processes: one: starting and adjusting the device; two: collecting the image without image; three: collecting the linear image; four: collecting the nonlinear image; five: computing the linear penetrant ratio; six: computing the nonlinear phase movement; seven: computing the third-order nonlinear refraction coefficient.

The invention discloses an X-ray phase imaging device comprising an X-ray photon source (1), an optical device (2) and an X-ray detector (4) which are sequentially arrayed. An X ray emitted by the X-ray photon source (1) is transmitted from one end of the optical device (2) to the other end of the optical device (2) to form a micro focal spot (5), and after the X ray passes through an imaged sample (3), an image is formed on the X-ray detector (4), and the optical device (2) is a single capillary, the outlet diameter is in the range of 1mum to 30mum. The imaging device can form a smaller micro focal spot in order to increase the spatial resolution of X-ray phase image, the X-ray phase image is clearer, and the X-ray phase imaging device has low cost and is convenient to popularize.

The invention relates to an application device based on light intensity transmission equation phase retrieval. According to the device, a light splitting sheet, a reflector and a spatial light modulator are used for dividing an imaging light beam into three sub-light beams; and an angular spectrum transfer function of the spatial light modulator is adjusted to make CCD obtain a focusing intensity image and a positive defocusing intensity image and a negative defocusing intensity image at the same time, wherein the positive defocusing intensity image and the negative defocusing intensity image have identical defocusing distance; then the light intensity transmission equation phase retrieval technology is applied on the collected images to rebuild the phase of an object. No mechanical movement or adjustment is required during the collecting process and only single exposure of single camera is needed so that quantitative phase position images can be retrieved stably and fast by use of the system; the application of traditional light intensity transmission phase imaging can be expanded to measure objects moving at high relative speed.

The invention provides a phase imaging method based on a thin scattering medium. The method comprises: placing a thin scattering medium in front of a digital image sensor, adjusting the distance between a target wavefront and the digital image sensor, matching the pixel size, making incident light to penetrate through the thin scattering medium to form speckles distributed spatially, and using thedigital image sensor for collecting formed speckle patterns; preprocessing the original speckle pattern; building a CNN and training a network by using the acquired and preprocessed picture pair data; extracting wavefront information in a speckle pattern by using a trained CNN network, the input of the network being a processed single-frame speckle pattern, and the output of the network being a phase grey-scale map or an amplitude grey-scale map or a complex amplitude corresponding to the wavefront according to a specific imaging task and a network training data set composed of different components. According to the invention, a single-frame, real-time and no-reference phase extraction method is realized, and the method has high image reconstruction quality and good robustness.

The invention discloses a phase microscopic imaging method based on deep learning, and the method comprises the following steps: employing a microscopic imaging system to collect an under-focus image,an in-focus image, and an over-focus image of a training sample; Obtaining a phase diagram of the training sample by using a phase recovery algorithm based on an intensity transmission equation; Andtaking the in-focus graph of the training sample and the corresponding phase graph as a training set to train the neural network. The training process only needs to be carried out once, then an in-focus image of an unknown sample is collected, and the phase image can be recovered by inputting the in-focus image into the trained network. The method has the advantages that reference light is not needed, a part of coherent light sources can be used, calculation is rapid and fast, limitation of boundary conditions is avoided, phase information of an object can be recovered only through one focus intensity graph, the method can be directly combined with an existing microscopic imaging system at low cost, and phase imaging is achieved while microscopic imaging is conducted.

The invention discloses a Fourier power spectrum detection-based single-pixel phase imaging method, and belongs to the field of phase imaging. The Fourier power spectrum detection-based single-pixel phase imaging method comprises the steps of employing a part of random Hadamard matrixes as measurement matrixes; employing an LED array (1) to irradiate, inputting the Hadamard matrixes, controlling alight-emitting sequence of array points of the Hadamard matrixes; forming a frequency spectrum surface (5) by an optical Fourier lens (4), measuring a central composite power signal by a single optical signal detector (6), and eliminating double image noise by employing a non-symmetric mask; and recovering phase information of a sample by employing frequency domain compression sensing reconstruction algorithm and a phase recovering algorithm. Fourier ptychography theory is used as a foundation, the compression sensing theory is employed as a method for reducing sampling data size, sampling can be performed at a low sampling rate, the data size is remarkably reduced, favorable phase information is obtained, and no halo effect is generated.

An interferometric-spatial-phase imaging (ISPI) system includes a substrate wafer. An alignment configuration is permanently embedded in the substrate wafer. The alignment configuration uses a global coordinate reference system by providing a plurality of global reference marks that encompass up to the entire substrate wafer. A plurality of alignment markings is provided on a surface in close proximity to the alignment configuration for obtaining continuous six-axis control of a scanning probe tip with respect to the global coordinate reference system.

The invention discloses a two-step phase-free imaging method for solving an electromagnetic inverse scattering problem based on a neural network. In the field of electromagnetic inverse scattering imaging, full-wave data need to be used in a full-wave data inversion algorithm, but actual measurement of the full-wave data is quite difficult. A phase-free inversion algorithm only needs to use phase-free total field data, actual measurement of the phase-free total field data is much easier, but the phase-free inversion algorithm has higher nonlinearity, and calculation is difficult. The method isgenerated by aiming at the advantages and disadvantages of a full-wave data inversion algorithm and a phase-free inversion algorithm; phase recovery is carried out on phase-free data in combination with the CNN, and then an image is reconstructed in combination with the full-wave data inversion algorithm.