39 results about "Digital holography" patented technology

The application discloses an optical element subsurface defect detection method and system based on phase contrast digital holography, and belongs to the field of precision measurement technology; the system adopts annular Bessel beam Kohler illumination, utilizes polarization modulation technology and a specially-made polarization contrast ring to realize synchronous four-step phase shift high-speed quantitative phase measurement in a U-shaped light path; the method acquires complex amplitude through a polarization camera, compensates for resolution loss by using a self-supervision super-resolution reconstruction algorithm fused with a physical model; full-field and local inverse diffraction reconstruction is carried out based on angular spectrum diffraction theory, high-precision depth positioning is realized based on the diffraction light complex amplitude distribution characteristics as a focusing criterion; three-dimensional information representation of defects is realized in combination with an optical field scattering and diffraction model and a machine learning algorithm; the application can realize high-sensitivity, high-signal-to-noise ratio, real-time in-situ quantitative detection and three-dimensional reconstruction of submicron defects without significantly increasing the cost.

In order to solve the light crosstalk problem caused by the low transmittance of general light splitting device in dual-wavelength digital holography, the application provides a method for solving the light crosstalk in dual-wavelength digital holography, which mainly adjusts the spot size of different wavelengths, adjusts the position of reference light while adjusting the size and direction of carrier frequency, and avoids the crosstalk area. The application can skillfully avoid the crosstalk area, is not limited by the transmittance of polarization splitting prism, dichroic mirror, filter and other light splitting devices, and can effectively solve the light wave crosstalk problem caused by the light splitting device with arbitrary transmittance in dual-wavelength digital holography.

An image reproduction device 6 reproduces an image including N different parameters of a wavelength range or the like, and comprises: a multiplexed hologram acquisition unit 61 for acquiring N to 2N multiplexed holograms obtained by multiplex-recording interference patterns for each parameter; a parameter selection unit 63 for selecting the parameters one by one; a hologram generation unit 64 for generating a calculation hologram including two light waves having the selected parameters from the multiplexed holograms; and a light wave restoration unit 65 for restoring one of the two light waves from the calculation hologram.

The present application relates to a kind of microstructure element cross-scale ultra-precision detection system and working method, belong to precision measurement technical field, this system is based on the phase information acquisition full aperture splicing system of digital holography and dynamic interference to record the information of object completely, and aberration correction is carried out to entire system, the problem of measurement accuracy is solved, then using the method that compressive sensing is combined with super-resolution algorithm, remove interference chart noise speckle simultaneously, improve resolution, to achieve higher measurement accuracy.Finally, by scanning splicing method to reach the full aperture large field of view detection of millimeter level, and using dynamic interference measurement system ensures the accuracy of splicing process.Compared with the traditional optical element surface detection system, the present application has the advantages of real-time, accuracy, high precision, large measurement range, etc., while ensuring the accuracy of surface detection, improves the efficiency of absolute detection method, can meet the needs of various kinds of microstructure optical element surface fast measurement.

The present invention relates to a cell analysis system based on virtual fluorescence generation technology, and a method therefor. According to the present invention, the system comprises: an input unit that receives a quantitative phase image of a sample including at least one cell through digital holography microscopy; and a cell identification unit that identifies at least one living cell by applying, to the received quantitative phase image, a cell segmentation mask generation model and a nuclei segmentation mask generation model constructed previously, and that masks a position of the nucleus of the living cell to derive an identification result. The system may further comprise a post-processing unit that derives a final result by applying a preset post-processing method to the derived identification result.

The present application relates to a kind of train wheel laser digital holography detection device and detection method, belong to nondestructive testing technical field.The present application obtains the holographic interferogram of train wheel by laser digital holography detection device, and based on holographic interferogram, three-dimensional model reconstruction is carried out to train wheel, and then relevant parameters are extracted to three-dimensional model, parameter is the data embodiment of the actual situation of train wheel, and staff determines the actual situation of train wheel by parameter;Using the detection device and detection method of the present application to carry out detection work to train wheel, can reduce the labor intensity of staff, improve detection efficiency, obtain higher accuracy detection result, improve the accuracy of judgment to the actual situation of train wheel.

The invention discloses a digital holographic lithography method based on light source phase coding and binary mask collaborative optimization, which comprises the following steps: 1, applying preset light source phase coding to an incident light field, and carrying out collaborative modulation with a binary amplitude mask to obtain a mask transmission light field; 2, propagating the transmission light field to a wafer plane by adopting an angular spectrum propagation model to obtain a wafer surface reproduction light field; 3, constructing a joint optimization function of the wafer surface light field intensity and a target graph, and carrying out collaborative optimization on a light source phase encoding parameter and a mask binarization structure parameter; and 4, performing holographic photoetching exposure and development based on an optimization result, and forming a high-resolution angular interference pitch line pattern on the surface of the wafer. By means of light source-mask collaborative coding, a traditional complex three-dimensional mask is simplified into a binary amplitude mask, the mask machining difficulty and manufacturing cost are reduced, meanwhile, the wafer surface angular resolution is effectively improved, and a feasible technical scheme is provided for a high-bandwidth digital holographic photoetching system.

The invention relates to a system (1) for digital holographic imaging, comprising at least the following components: - a beam splitter (2), - a retroreflector array (3) comprising a plurality of retroreflector elements (30), - a reference mirror (4), wherein the system (1) is configured to superimpose the object light (100) reflected off the reference mirror (4) and off the retroreflector array (3) such that a plurality of interference patterns that can be assigned to the respective retroreflector elements (30) are produced, wherein the system (1) has a phase-adapting optical structural component (5) for predefined phase adaptation of the object light (100), characterized in that the phase-adapting optical structural component has an assigned angle-of-incidence / phase relation (1000) for each of a predefined plurality of incidence directions (e) of the object light (100), wherein the phase-adapting optical structural component (5) is configured to impress phases (Φ) on the object light (100) in accordance with the assigned angle-of-incidence / phase relation (1000) for each of said plurality of incidence directions such that the interference patterns comprise information with which a hologram correspondingly reconstructed from said interference patterns has an improved resolution with respect to a system (1) without the predefined phase adaptation.

This application provides a PCB defect detection method and apparatus based on digital holography, belonging to the field of printed circuit boards. The method includes: acquiring multiple consecutive frames of interference fringe patterns; wherein, during the acquisition of the interference fringe patterns, the light intensities of the object beam and reference beam are acquired in real time and adjusted to make their intensities equal, thereby improving the quality of the interference fringe patterns; inter-frame alignment and temporal fusion are performed on the multiple frames of interference fringe patterns, followed by weak light enhancement processing to obtain enhanced interference fringe patterns; based on the enhanced interference fringe patterns, the three-dimensional topography of the PCB is reconstructed; and based on the reconstructed three-dimensional topography of the PCB, defect detection is performed on the PCB.

The application relates to an optimal reconstruction distance selection method, device and medium for off-axis digital holography, which comprises the following steps: running an off-axis digital holography optical path system to obtain an off-axis hologram to be processed; performing fractional Fourier transform on the off-axis hologram to obtain time-frequency domain information of the off-axis hologram; performing filtering processing on the positive first-order time-frequency domain information, and then performing fractional inverse Fourier transform to obtain positive first-order spectrum information; setting a reconstruction distance range, and then setting a plurality of candidate reconstruction distances at intervals of a fixed step length; performing an angular spectrum method to obtain corresponding reconstruction amplitude images; constructing a second-order total variation evaluation function, and calculating a second-order total variation function value of each reconstruction amplitude image; taking the reconstruction distance as the horizontal coordinate and the second-order total variation function value as the vertical coordinate, drawing a second-order total variation evaluation function curve, and determining the optimal reconstruction distance according to the attribute of a measured object. Compared with the prior art, the application has the advantages of high accuracy and strong robustness.

This invention discloses a multi-image encryption method based on 3D face keys and multiplexed digital holography. The encryption steps include: using 3D face high-order data acquisition technology, chaotic face structured light phase mask generation technology, grating modulation technology, multiplexed digital holographic coding technology, and watermark embedding technology based on discrete wavelet domain singular value decomposition, multiple plaintext information images can be encrypted into an amplitude-type holographic ciphertext and embedded into a host image; the decryption steps include: the user must first calculate the face similarity using a 3D face multilayer perceptron neural network. If the similarity exceeds a preset threshold, authentication is successful. Then, the final decryption result is generated using watermark image extraction technology based on discrete wavelet transform, image decryption technology based on the Cramer-Kroni relation, and spectral filtering technology; otherwise, authentication fails. This method has advantages such as a large key space, high sensitivity, strong robustness of the 3D face key, and low decryption crosstalk.

The application discloses a precision surface three-dimensional appearance measurement device and method based on phase shift digital holography, which comprises the following modules: a light beam splitting module for generating a reference light and an object light beam irradiated to the surface of a measured object and returned; a reference light beam adjusting module for receiving the reference light generated by the light beam splitting module, generating different reference light beams based on different voltage forces, and generating different reference light beams after different brightening and increasing; a lens imaging system for receiving the object light beam generated by the light beam splitting module and performing light beam amplification; a second polarization beam splitter for receiving the different reference light beams generated by the reference light beam adjusting module and the amplified object light beam of the lens imaging system, and performing light beam combination; a linear polaroid for respectively interfering a series of light beams after combination; an image acquisition module for acquiring a series of interference images; and a computer for receiving the series of interference images transmitted by the image acquisition module, extracting phase information of the object light by using a phase shift algorithm, and realizing measurement of the three-dimensional appearance of the surface of the measured object.

A synthetic aperture quantitative phase imaging method based on a hybrid of digital holography and Fourier ptychography. A programmable LED array which is annularly arranged is mounted on an off-axis digital holographic system for providing oblique illumination at varying angles; accurate noise-containing low-frequency information of an object is obtained by means of digital holography and is used as initial estimation; and then, high-frequency information of the object is reconstructed by means of a Fourier ptychographic algorithm based on intensity measurement, so as to realize synthetic aperture quantitative phase imaging. Using the accurate low frequency provided by holography as initial estimation ensures the accuracy of phase retrieval and wavefront aberration reconstruction, without strictly meeting matching illumination conditions, and reduces the number of intensity graphs required by Fourier ptychography; and a non-interferometric phase retrieval method based on Fourier ptychography improves the imaging resolution to an incoherent diffraction limit, and also effectively solves the problem of inherent speckle noise in digital holography.

The utility model belongs to the field of anti-counterfeiting marks, and discloses a multicolor digital holographic positioning hot stamping film and water transfer printing paper. The stripping layer, the information unit layer, the heat preservation unit layer and the back glue layer are arranged on the base film layer layer by layer, the digital information layer of the color pattern layer is formed through jet printing of a digital jet printing machine of a multi-color module, and multi-color three-dimensional color patterns can be formed at a time in cooperation with position sleeving mold pressing. In this way, the problems that in the silk-screen printing or offset printing process, due to the fact that alignment errors, ink leakage and the like often occur, product scrapping is large, and time and labor are consumed can be solved, the back glue layer can be conveniently and directly pasted on carriers such as wine bottles, baking is avoided, and the printing device is more convenient and faster to use.

The invention discloses an optical material defect identification method for vibration deformation measurement through a time average holographic method, and relates to the technical field of digital holographic measurement, the optical material defect identification method specifically comprises the following steps: simplifying an optical material into a circular thin plate, and obtaining the influence of the surface defect of the circular thin plate on the amplitude; obtaining the influence relation of the exposure time change of the circular thin plate under sinusoidal vibration excitation on the reconstruction effect of the time-averaged hologram; constructing a digital holographic reflective optical path; respectively shooting time average holograms before and after vibration deformation of the to-be-detected sample; extracting interference information of the to-be-detected sample; inverse Fourier transform is carried out to obtain complex amplitude distribution, phase extraction is carried out, and the phase difference before and after vibration deformation is calculated; and based on the phase difference before and after the vibration deformation, obtaining the occurrence position of the surface defect of the to-be-detected sample to realize defect identification. According to the invention, the identification of different types of defects is realized by positioning the areas with obviously abnormal phase difference stripes.

The invention discloses a dynamic monitoring lens surface defect detector, which belongs to the field of optical detection and comprises an optical fiber light source, an optical fiber beam splitter body is arranged below the optical fiber light source, an optical fiber connector is arranged below the optical fiber beam splitter body, a convex mirror or a concave mirror is arranged on the left side of the optical fiber connector, and the convex mirror or the concave mirror is arranged on the right side of the optical fiber connector. A convex mirror or a concave mirror is arranged on the left side of the base, a mirror to be measured is arranged above the convex mirror or the concave mirror, a telecentric lens is arranged above the mirror to be measured, a half-wave plate is arranged above the telecentric lens, and a collimator is arranged on the left side above the half-wave plate; the lens surface defect detection is realized by adopting digital holography, meanwhile, the advantages of large depth of field and high resolution of the digital holography are applied to the field of lens surface defects, a foundation is laid for rapid detection of the lens surface defects, and the method is clear and convenient to operate.

The application relates to the technical field of optical imaging, and particularly discloses a system for realizing real-time edge enhancement of double-channel self-interference digital holography through T-Net, which comprises the following steps: a double-light-source unit irradiates a target object through a collimating lens; a shared imaging lens collects reflected light; a spatial light modulator is loaded with a vortex phase for edge modulation; a half-wave plate and a polarization beam splitter are used for beam splitting to form orthogonal polarization double channels; double CMOS image sensors synchronously collect holograms with a phase shift difference of pi; a data processing unit reconstructs an edge-enhanced image by eliminating a background term and a conjugate image and an angular spectrum propagation function through T-Net neural network parameters pre-stored in a memory and combined with a three-step phase shift algorithm to complete a third pi / 2 phase shift graph.

The invention relates to a system (1) for digital holographic imaging, comprising at least the following components: - a beam splitter (2) - a retroreflector array (3) comprising a large number of retroreflector elements (30), - a reference mirror (4), wherein the system (1) is configured to superimpose the object light (100) reflected by the reference mirror (4) and by the retroreflector array (3) so that a multitude of interference patterns attributable to the respective retroreflector elements (30) are created, wherein the system (1) has a phase-adapting optical structural component (5) for predefined phase adaptation of the object light (100), characterized in that the phase-adapting optical structural component has an associated angle-of-incident phase relation (1000) for each of a predefined plurality of incidence directions (e) of the object light (100), wherein the phase-adapting optical structural component (5) is configured to imprint phases (Φ) on the object light (100) for each of these plurality of incidence directions according to the associated angle-of-incident phase relation (1000), so that the interference patterns contain information with which a hologram reconstructed accordingly from these interference patterns has an improved resolution with respect to a system (1) without the predefined phase matching.

1. Name of the designed product: detection vehicle (road surface digital holography and road structure ground penetrating three-dimensional radar). 2. Use of the designed product: used as a detection vehicle. 3. Design points of the designed product: in shape. 4. Picture or photo best indicating the design points: perspective view 1.

The application discloses a kind of data processing methods of road surface disease image fusion based on three-dimensional digital holography, and original graph is obtained by generating digital interference fringe image and projecting to road surface through laser interferometer and collecting road surface;Computer simulation restoration reconstruction is obtained three-dimensional holographic disease graph;Two-dimensional disease graph is obtained using Fourier transform;Three-dimensional holographic disease graph and two-dimensional disease graph are fused to generate fusion disease graph;Using specified data, the final training model is obtained by testing simulation correction to fusion model.This application can obtain three-dimensional disease graph and two-dimensional disease graph according to original hologram, and through least square method, left and right and before and after disease graph are spliced to form multi-size disease database, the combination of two-dimensional and three-dimensional disease graph data not only greatly improves data precision, but also improves image quality, and disease detection type covers various diseases of road surface, which can facilitate equipment to automatically identify road surface disease.

A metrology system comprising: a first illumination beam, the first illumination beam configured to be diffracted by a target; a second illumination beam, the second illumination beam configured to be dispersed by a dispersive element, wherein the dispersive element is configured to introduce a tilt in the second illumination beam in at least one direction; a detector, the detector configured to detect an interference pattern of the first illumination beam diffracted by the target and the second illumination beam dispersed and tilted by the dispersive element; and a processor operatively connected with the detector, the processor configured to determine a phase and / or amplitude of a waveform of the first illumination beam after it has interacted with the target based on the interference pattern detected by the detector.

The application discloses a method for simultaneously and dynamically measuring two-dimensional distribution of optical activity and circular dichroism of a chiral sample by using circularly polarized object light wave digital holography. The method utilizes the modulation characteristics of left and right circularly polarized light amplitude and phase of the chiral sample, and the full-field, non-contact and high-precision dynamic measurement advantages of digital holography on the complex amplitude distribution of the light field. Left and right circularly polarized light is taken as object light wave respectively, and the simultaneous and dynamic measurement of the two-dimensional distribution of optical activity and circular dichroism of the chiral sample can be realized by using double-exposure digital holography.

The invention discloses a real-time quantitative phase detection device and method based on white light diffraction digital holography, and belongs to the technical field of optical imaging. The device comprises a collimation light source, a light collecting mirror, an aperture diaphragm, a convergent lens diaphragm, a convergent lens, a polarizer, a polarization beam splitter prism, an achromatic wave plate, a tube lens, a microscope objective, a measured reflective object, a reflective concave grating, an analyzer, a spatial filter, a positive lens and a 3CMOS camera. The spatial filter is located between the analyzer and the positive lens. According to the method, a 3CMOS camera is adopted, three light intensity images of different channels are recorded at the same time, white light diffraction digital holography is used for real-time quantitative phase detection, spatial domain multiplexing is achieved through polarization regulation and control, through halo effect compensation and TIE-based direct phase demodulation, complex PU steps are omitted, complex amplitude distortion correction operation of DHM is avoided, and the method is suitable for large-scale industrial production. And the robustness of the real-time quantitative phase detection device is improved. According to the invention, high-precision and high-stability three-dimensional quantitative phase detection can be realized.

Systems and methods for generating multiple mutually variant wavelengths of coherent radiation for three-dimensional imaging of a physical object, such as a tooth, are disclosed. A single radiation source, such as a laser diode, emits coherent electromagnetic radiation. A highly dispersive optical element, such as an echelle diffraction grating, separates radiation having specific wavelengths from the emitted spectrum into distinct beams. Optical components, such as optical masks, mirrors, and lenses, select and orient desired beams to illuminate the object. Small changes in drive current or heatsink temperature of the radiation source similarly affect all wavelengths of the emitted spectrum, so the relative wavelength differences of the desired beams of radiation remain constant. This wavelength stability is useful for synthetic wavelength generation for digital holography and minimizes errors in object shape profile measurements at various scales. Use of a single radiation source also reduces system cost and complexity.

The invention discloses an angular spectrum diffraction method based on dynamic acquisition of effective information of an object field spectrum, and the method comprises the steps: dynamically extracting the effective information in the object field spectrum through a multistage threshold image segmentation algorithm, adaptively adjusting the filtering bandwidth, optimizing a sampling strategy of a transfer function, and obtaining the effective information of the object field spectrum. Therefore, the calculation complexity and the memory occupation are remarkably reduced while the calculation precision is ensured. The method solves the problems of undersampling and computing resource waste in far-field diffraction calculation of a traditional angular spectrum method, is particularly suitable for diffraction calculation of a complex light field containing a high-frequency component, and has a wide application prospect in the fields of digital holography, light beam quality analysis and the like.

A lens-less system for holographic imaging or a holographic imaging device is provided. The method / device includes a stationary image sensor to capture an image of a sample illuminated by light from a stationary illumination source. A reference lens-less holographic image may be captured and used as a base line to reduce image artifacts and / or remove noise from the lens-less holographic image. Since real wavefronts produced by a diverging point source are neither perfectly spherical nor planar but a combination of both qualities, theoretical estimates for wavefront reconstruction based on perfectly planar or spherical incident waves cannot be applied accurately. The method / device here provides a solution by performing a calibrated wavefront reconstruction based on equations governing coherent light propagation for both spherical waves and planar waves with a mathematical correlation between numerical magnification and propagation depth to produce accurate three-dimensional details of the object.

A method for chromatic aberration compensation in dual-wavelength digital holography is provided. The method includes: obtaining a dual-wavelength interferogram simultaneously containing two wavelengths; obtaining complex amplitudes of the two different wavelengths at a camera plane; performing numerical propagation on object wavefronts of the two wavelengths within a defocus range to obtain complex amplitudes of the two wavelengths at different axial propagation positions within the defocus range using an angular spectrum method; calculating single-wavelength phase distributions corresponding to the axial propagation positions within the defocus range; calculating, for all combinations of different axial propagation positions for the two wavelengths, dual-wavelength synthetic phase distributions; obtaining a chromatic-aberration-compensated dual-wavelength synthetic phase by identifying a combination of optimal axial propagation positions at which the gradient value of the corresponding dual-wavelength synthetic phase distribution reaches a minimum, and subtracting two single-wavelength phases corresponding to the identified axial propagation positions.

Apparatuses and methods for analyzing fluid samples are provided. For example, an example apparatus may include a fluid imaging chamber, at least one illumination source component, and an image sensor component. In some examples, the fluid imaging chamber comprises a flow channel for receiving a fluid sample. In some examples, the at least one illumination source component is configured to emit at least one light beam, and the at least one light beam is directed through the fluid sample in the flow channel from a top surface of the fluid imaging chamber. In some embodiments, the image sensor component is positioned under a bottom surface of the fluid imaging chamber and configured to generate digital holography image data of the fluid sample.

The application discloses a kind of based on multi-stage deep learning's incoherent digital holography weak light three-dimensional imaging method and system, belong to optical imaging technical field.The method includes: obtaining the multiple phase shift incoherent digital hologram collected under weak light condition;It is input to the first stage deep learning network model trained in advance, and the corresponding enhanced hologram is output, and the model is trained with weak light hologram as input, normal light hologram as label;The preliminary image is obtained by digital reconstruction to enhanced hologram;Preliminary image is input to the second stage deep learning network model trained in advance, and the final high-quality reconstructed image is output, and the model is trained with the image obtained by digital reconstruction to enhanced hologram as input, and the digital reconstructed image of normal light hologram is label;The fidelity and signal-to-noise ratio of three-dimensional reconstruction of FINCH system under weak light condition can be significantly improved without changing the existing optical hardware structure.