59 results about "Digital holography" patented technology

The application discloses a holographic multiplexing imaging method based on Kramers-Kroning relation, relates to the field of high-throughput multi-channel multiplexing digital holographic imaging technology, and is based on the quantitative phase measurement and the improvement of the space-bandwidth product; the holographic multiplexing imaging method based on Kramers-Kroning relation directly detects the complex amplitude field without any constraint; in addition, the holographic multiplexing imaging method can allow the target spectrum and other spectra to overlap without sacrificing the space-bandwidth and the time resolution, can realize the quantitative optical imaging without scanning, and provides a new way for significantly improving the application of digital holography and quantitative optical imaging.

The invention discloses an image encryption method based on phase-shift digital holography and a multi-mode biological characteristic key, which comprises the following encryption steps of: firstly, encrypting a grayscale image into a DNA compilation result by using DNA coding and an iris chaos mask; secondly, encrypting a DNA compiling result into three ciphertext holograms by using phase-shift digital holography and fingerprint and finger vein chaos masks; the decryption step comprises the following steps of: firstly, authenticating three biological characteristics of decrypted iris, fingerprint and finger vein; if the authentication is successful, the iris chaos mask and the fingerprint and finger vein conjugate chaos mask for subsequent decryption are generated by the system. And finally, obtaining a final decrypted image by using a digital holographic reconstruction technology and a DNA decoding technology. The method provided by the invention has the advantages of high security level, high biological key robustness and high digital key sensitivity.

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.

This invention discloses a digital holographic 3D reconstruction system and method based on a single-cavity dual-optical comb, belonging to the field of digital holographic 3D measurement technology. The invention includes: a single-cavity dual-optical comb, a coarse wavelength division multiplexer, a first fiber amplifier, a second fiber amplifier, a first fiber filter, a second fiber filter, a first fiber beam expander, a concave mirror, a second fiber beam expander, a beam splitter, an image sensor, and a computer. The single-cavity dual-optical comb emits two pulses, which are split, amplified, and filtered. The measurement light and the reference light produce interference fringes, forming a hologram. This invention uses a single-cavity dual-optical comb as a light source to achieve the separation of the zero-order image, twin image, and target re-phenomenon in coaxial holography, improving the quality of holographic imaging and facilitating engineering implementation. Based on multi-wavelength heterodyne technology, combined with the wide spectral bandwidth and high temporal coherence of the optical comb, this invention suppresses the influence of noise, enabling the measurement of large-size objects and expanding the application scenarios of 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 invention relates to an optical system (1) comprising at least the following components: a first holography arrangement (2) comprising a first diffraction element (3) which is formed by a first prism arrangement (4) having at least a quadrangular base surface, wherein a lateral surface of the first prism arrangement (4) has the following lateral surface regions: a first entrance surface (31) for reference light (100) extending along a first entrance plane (310), a second entrance surface (32) for object light (200) extending along a second entrance plane (320), wherein the first and second entrance surfaces (31, 32) form opposite lateral surface regions of the first prism arrangement (4), an exit surface (33) which extends along an exit plane (330) and through which diffracted reference light (102) and diffracted object light (201) can exit from the first diffraction element (3), a prism surface (34), opposite to the exit surface (33), extending along a prism plane (340), an optical transmission diffraction grating arrangement (36) which is arranged in the first diffraction element (3) and extends along a diffraction plane (360), which intersects the first entrance plane (310), between the first entrance surface (31) and the exit surface (33), wherein the transmission diffraction grating arrangement (36) of the first diffraction element (3) comprises at least one first volume phase hologram grating, and in that the first holography arrangement (2) has, on the side of the prism surface (34), a first mirror (35) having a first mirror plane (350), wherein the first mirror plane (350) encloses an angle α with the diffraction plane (360) and the prism plane (340) encloses an angle ω2 with the diffraction plane (360), wherein at least one of the angles α, ω2 is different from 45°.

The application relates to a method for eliminating off-axis digital holographic zero-order terms, which comprises the following steps: obtaining holographic data of off-axis digital holography, and obtaining spectrum information through Fourier transform. Pixel points with intensity higher than a certain value in the spectrum are selected as initial data objects, the initial data objects are divided into clustering categories through a K-means clustering method, and clustering centers are calculated. The clustering centers are taken as initial mean values of GMM, the covariance of each cluster is calculated, the mixing coefficient of GMM is calculated according to the proportion of data points in each cluster, the posterior probability of each data point belonging to each Gaussian distribution is calculated through Bayes theorem, and the GMM model is updated, so that the final clustering result is obtained. The clustering result located at the center position of the spectrum is eliminated, and the zero-order spectrum information is eliminated. Compared with the prior art, the application has the advantages of high accuracy and strong universality.

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 application discloses a cross-scale composite wavefront sensing method based on a deep learning model, combines a Shack-Hartmann wavefront sensor (SHWFS) and off-axis digital holography (OADH) through a composite wavefront sensing system, fuses data of a wavefront measured by the composite wavefront sensing system by using an MSWM-Net model based on a deep neural network, realizes complementary advantages of performances of the two measurement systems, and further obtains a high-confidence reconstructed wavefront. When measuring a wavefront aberration containing different spatial frequencies, the method not only solves the problem of low phase accuracy in SHWFS measurement, but also solves the limitation of wrapping the wavefront in a period in OADH measurement. The feasibility and effectiveness of the method in wavefront detection are verified through tests. The application is more easy to realize quantitative measurement of atmospheric turbulence aberration, can provide design input parameters for an atmospheric turbulence aberration correction system, and can be used for distortion wavefront detection of the atmospheric turbulence correction system.

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 an underwater active polarization imaging method based on off-axis digital holography, and relates to the field of computational optical imaging. According to the technical scheme, on the basis of the off-axis digital holography, the characteristics of an active polarization coherent light source are utilized, cross-polarization holograms (0 degree and 90 degrees) are recorded through interference of reference light and object light, after a + 1-level spectrum center is displaced through Fourier transform, amplitude information is reconstructed through reverse angular spectrum diffraction, and the phase position of the object light is calculated. And accurately separating a target optical signal in combination with an active polarization model. The off-axis digital holography is utilized to enable the non-scattered object light to interfere with the reference light, the scattered light interference is inhibited, the image definition and contrast in a turbid underwater environment can be effectively improved, a new technical path is provided for optical imaging in a high-scattering environment, and the method is suitable for optical imaging requirements in an underwater complex environment.

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.

A metrology system comprising: an illumination source, the illumination source configured to produce a beam of illumination; wherein at least a first portion of the beam is diffracted by a target and wherein at least a second portion of the beam is not diffracted by the target; a detector, the detector configured to detect a recombination of the first portion of the beam diffracted by the target and the second portion of the beam not diffracted by the target; and a processor operatively connected with the detector, the processor configured to determine a phase and / or amplitude of a waveform of the first portion of the beam after it has interacted with the target based on the recombination detected by the illumination detector.

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.

The application discloses a hologram generation method based on deep learning and angular spectrum method, and belongs to the field of deep learning and digital holography.The application solves the problems of long time consumption, high cost, and difficulty in guaranteeing the quality of obtained data in the existing training data set acquisition method, and the problem of poor quality of a reconstructed image obtained by using a denoised hologram output based on the existing deep learning method.The application proposes an HG-Net network structure, uses multiple input intensity distributions and holograms obtained by ASM propagation as training data sets by randomly adjusting the density and size of the speckle, so as to improve the complexity of the training data set.The HG-Net network is trained by using the training data set, so as to improve the generalization of the model.The real part hologram and the imaginary part hologram output by the HG-Net network are combined to obtain a generated hologram, and numerical and optical reconstruction is carried out based on the generated hologram.The method can be applied to hologram generation.

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.