11 results about "Coherent diffraction imaging" patented technology

The invention belongs to the technical field of micro-nano processing, and particularly relates to a Pt-HSQ-based high-resolution X-ray Fresnel zone plate and a preparation method thereof. According to the X-ray Fresnel zone plate, a Pt-HSQ metal-inorganic material system is adopted, a diffraction structure with a large aspect ratio and Pt material quasi-periodic dense stripes specially needed by an X-ray zone plate lens is formed through electron beam lithography and an ALD process, and diffraction focusing from a soft X-ray wave band to a hard X-ray wave band and imaging with an amplification function are achieved. The wave zone plate has excellent mechanical stability, and the irradiation resistance and morphology retentivity of the wave zone plate under high-energy irradiation are remarkably improved. And high-resolution X-ray focusing elements with different energy wavebands and different focal lengths can be prepared according to geometric design and material selection of the wave zone plate. The lens is suitable for microscopic imaging, coherent diffraction imaging, X-ray spectrum, nanometer detection and other scenes of a synchrotron radiation or off-line laboratory X-ray light source, and has wide popularization value and application prospect.

This application belongs to the field of coherent diffraction imaging technology, specifically disclosing an ultra-low dose coherent diffraction imaging method and apparatus. Based on a blind source separation strategy, this application uses principal component analysis to process the acquired diffraction signals, performing noise separation and updating in reciprocal space. This effectively separates mixed noise energy into noise components, thus avoiding crosstalk to the reconstruction process and significantly improving the convergence stability and robustness of coherent diffraction imaging when reconstructing diffraction signals with extremely low signal-to-noise ratios under ultra-low exposure doses. Simultaneously, this application constructs noise components separately for each scanning position and correlates noise components at different positions through low-dimensional spatial projection, achieving non-stationary noise separation. This enables more effective handling of random noise caused by the low quantum efficiency of ultra-short band detectors, thus maintaining extremely high noise robustness and reconstruction accuracy even under ultra-low exposure doses, achieving an effective improvement in resolution.

The invention discloses a double-domain joint evaluation method for imaging quality in wide-spectrum coherent diffraction imaging, which belongs to the related technical field of wide-spectrum coherent diffraction imaging, and comprises the following steps: 1, measuring light source spectrum distribution for wide-spectrum coherent diffraction imaging, and imaging a wide-spectrum diffraction field through an imaging algorithm; 2, obtaining a current reconstructed image and actually measured diffraction light intensity after each iteration of the imaging algorithm, constructing wide spectrum diffraction light intensity by using spectral distribution and reconstructed image values, and using and calculating diffraction field errors; 3, performing no-reference quality evaluation on the reconstructed image after each iteration, and calculating an image error; and 4, using weighting to form a double-domain joint evaluation result. The method can effectively solve the problem that the existing wide-spectrum laminated diffraction imaging lacks a unified and accurate evaluation method, thereby improving the reliability and consistency of reconstruction quality evaluation.

The application provides a single-pixel diffraction imaging method and device, and belongs to the field of coherent diffraction imaging and computational photography, wherein the method comprises the following steps: (1) in the single-pixel imaging light path, different modulation sequences are used to modulate the illumination light beam of the target scene, and a single-pixel detector is used to record the intensity value of a one-dimensional sequence; (2) the intensity value corresponding to the different modulation sequences is used to replace the amplitude value of the reconstructed diffraction light field on the detector plane, and then alternating iteration calculation is performed until the target scene is reconstructed. The application has the advantages of simple structure, strong operability, wide application range and strong expandability. Through the application, the cost of single-pixel diffraction imaging can be reduced, fast and accurate measurement of the target scene is realized, and convenience is brought to high-quality single-pixel imaging.

The invention discloses a reflective coherent diffraction imaging method and system based on tilt phase correction, and relates to the technical field of extreme ultraviolet optical imaging. The method comprises the following steps: acquiring extreme ultraviolet diffraction signals to obtain an original data matrix; acquiring an initial inclination angle value of the sample; executing a phase recovery iteration process: substituting the current inclination angle parameter into a coordinate mapping relational expression to calculate a corrected frequency domain coordinate, and determining a reflectivity compensation coefficient; performing coordinate resampling and amplitude correction on the original data to generate correction data; calculating a reconstruction error and dynamically updating an inclination angle parameter; and outputting a reconstructed image if the convergence condition is satisfied, otherwise, returning to re-execute. According to the method, the inclination angle is used as a variable optimization variable to be embedded into an iterative closed loop, and the extreme ultraviolet multilayer film reflectivity compensation is combined, so that the problems of geometric distortion and intensity artifacts caused by sample inclination are effectively solved, sub-pixel-level angle correction precision and high-fidelity image reconstruction are realized, and the imaging efficiency and stability are remarkably improved.

The invention discloses a hyperspectral diffraction imaging device, system and method based on blind coding, and relates to the technical field of hyperspectral coherent diffraction imaging.The method comprises the steps that a hyperspectral light beam emitted by a light source is transmitted to a mask plate through a reflector after being subjected to beam expanding, focusing and collimation; controlling the mask plate to move from the first position to the second position, so that the mask plates at different positions before and after movement have overlapped areas along the light path direction, and obtaining a diffraction image of each lamination scanning position; and according to the diffraction image, performing joint reconstruction on the unknown mask plate, the spectrum and the imaging object by using a broadband phase reconstruction algorithm based on multi-parameter constraint to obtain amplitude and phase information of the reconstructed mask plate, the spectrum and the imaging object so as to complete hyperspectral illumination coherent diffraction imaging. According to the method disclosed by the invention, multi-spectrum amplitude-phase-spectrum joint reconstruction of the hyperspectrum under low-time coherent illumination can be realized by utilizing laminated scanning under the condition that codes are unknown.

The invention belongs to the technical field of imaging, and discloses a monochromatization method applied to wide-spectrum coherent diffraction imaging, which aims at a wide-spectrum coherent diffraction imaging experiment and reconstructs an obtained multi-wavelength diffraction pattern into a diffraction pattern under a single wavelength through spectral characteristic analysis. According to the method, based on a theoretical model in which a wide-spectrum diffraction pattern is a non-coherently superposed single-color wavelength diffraction pattern, the single-color wavelength diffraction pattern is accurately extracted in combination with a gradient descent optimization algorithm. According to the method, the dependence of traditional coherent diffraction imaging on a monochromatic source is broken through, and the calculation efficiency of monochromatization reconstruction is remarkably improved. The method is suitable for a coherent diffraction imaging scene of a wide-spectrum weak coherent light source, the problem of light intensity attenuation caused by a traditional light splitting scheme is effectively avoided, and a new solution is provided for high-resolution imaging under the weak light source. Meanwhile, the method is expected to be expanded to a desktop attosecond light source and other novel light source systems, and key technical support is provided for ultrafast process imaging under the attosecond scale.

The invention discloses a spectrum-image combined measurement device and system based on double networks, and relates to the field of wide spectrum coherent diffraction imaging, the spectrum-image combined measurement device comprises a light source, a first lens, an aperture diaphragm, a second lens, a third lens, an imaging object and a CMOS camera which are arranged along a light path direction, the CMOS camera receives a diffraction pattern and transmits the diffraction pattern to a processor, and the processor is used for processing the diffraction pattern. The processor reconstructs the received diffraction pattern by adopting a spectrum-image combined measurement method based on double networks, including collecting the diffraction pattern, and obtaining a fused diffraction pattern after high dynamic range fusion; a monochromatic diffraction pattern is collected, an actual diffraction distance is obtained in combination with the monochromatic diffraction propagation model, and an actual wide-spectrum physical propagation model is constructed based on the actual diffraction distance; and based on the fused diffraction pattern, reconstructing the image and the spectrum by using a spectrum-image joint reconstruction algorithm based on double networks to obtain a reconstructed diffraction pattern and spectrum. Spectrum calibration is not needed, the image and the spectrum can be reconstructed at the same time, and the difficulty of wide-spectrum diffraction imaging is greatly lowered.

This application belongs to the field of coherent diffraction imaging, specifically disclosing a method and system for reconstructing stacked diffraction imaging based on subgradient projection regularization. Through this application, based on the convex problem optimization theory of subgradient projection, a spatially varying gradient weighting function is further introduced into the stacked diffraction imaging reconstruction model to adaptively adjust the update step size, thereby improving the iterative convergence speed. This method can achieve a balanced improvement in convergence speed within the support domain without introducing any additional computational overhead by penalizing or suppressing extreme step sizes during the update process. Furthermore, this method requires no hardware modification, is directly compatible with stacked diffraction imaging models, and reduces the parameter sensitivity of the iterative algorithm during reconstruction, achieving robust convergence without fine-tuning.

The application relates to the technical field of optical detection, and discloses a material surface defect super-resolution optical detection system and method. The system and method utilize an evanescent wave chip to form a structured evanescent wave field on a surface as a near-field illumination probe, change the relative position of the probe and a sample through an angle or wavelength tuning non-mechanical scanning mode, and acquire a set of far-field polarization resolution diffraction patterns through a diffraction signal acquisition module. A central control and data processing unit carries out iterative calculation on the diffraction data set through a vector coherent diffraction imaging algorithm, and simultaneously reconstructs the complex amplitude distribution of the probe and a high-resolution Jones matrix image of the sample. Through analysis of the Jones matrix, quantitative detection of the morphology, size and anisotropic physical properties of the surface defect can be completed. The application avoids vibration caused by mechanical scanning, and realizes high-stability and high-resolution nondestructive detection.

The present application belongs to the technical field of coherent diffraction imaging, and discloses a kind of laminated diffraction position correction imaging method, system and electronic equipment, wherein the method comprises: for each scan position coordinate of motion platform, the minimum difference between the calculated diffraction light field intensity information and the collected diffraction light field intensity information is the optimal value by particle swarm algorithm, and the updated integer pixel position coordinate of motion platform is obtained by iterative updating;The cross-correlation peak position before and after the diffraction exit wave update of each updated integer pixel position coordinate of motion platform is calculated, and the updated sub-pixel position coordinate of motion platform is obtained by continuously searching and updating the irradiation probe position;The complex amplitude function of irradiation probe and sample to be measured is calculated, and the amplitude and phase of sample to be measured and irradiation probe are reconstructed from this.The convergence speed of position correction algorithm is improved by effectively combining particle swarm position correction method and cross-correlation position correction method, and the final accuracy is also guaranteed.