43 results about "Dynamic speckle" patented technology

A 2D or 3D velocity field is reconstructed from a cross-correlation analysis of image pairs of a sample, without first reconstructing images of the sample spatial structure. The method can be implemented via computer tomographic x-ray particle image velocimetry, using multiple projection angles, with phase contrast images forming dynamic speckle patterns. Estimated cross-correlations may be generated via convolution of a measured autocorrelation function with a velocity probability density function, and the velocity coefficients iteratively optimised to minimise the error between the estimated cross-correlations and the measured cross-correlations. The method may be applied to measure blood flow, and the motion of tissue and organs such as heart and lungs.

The present invention relates to a novel method and a novel device, incorporating dynamic speckle lighting with a conventional wide field fluorescence microscope organically to implement approximately confocal fluorescence microscopy (i.e., quasi-confocal fluorescence microscopy). The present invention employs an argon ion laser as the light source; the exciting light passes through a scattering object, a relay light path system for expanding and shaping, and then is coupled to the fluorescence microscope and focused to the sample. The stepping and revolution of the scattering object is controlled with a computer to produce a dynamic speckle pattern on the sample. The received fluorescent images are processed to obtain high-resolution spatial chromatographic images under no need to scan condition. The method can be used to obtain high-resolution three-dimensional chromatographic and microscopic image information of biological tissue samples in a non-intrusive manner. The device has simple structure, high cost-performance ratio, and is favorable for post data processing, easy to operate and apply; therefore, the device and method have a wide market application prospect and great significance for clinical diagnosis and life science research.

The invention discloses a laser speckle optical path and a laser projection light source system, and relates to the technical field of laser display. The system comprises a diffusion assembly and a lens assembly used for collimation and spotlight, the diffusion assembly is composed of at least two diffusion parts, wherein one of the diffusion parts is a dynamic speckle device, the other diffusionparts are static speckle devices, and the movement mode of the dynamic speckle device is cyclical rotation; and the lens assembly is arranged among the diffusion parts. The laser speckle optical pathand the laser projection light source system have the advantages that better speckle and facula homogenization functions can be achieved through the combined use of the dynamic diffusion assembly andstatic diffusion assemblies; the laser beams are diverged and collimated repeatedly to greatly reduce the spatial coherence of the laser beams, thereby effectively solving the problem of speckle; thelaser speckle optical path is simple in structure and small is size, and can be integrated easily in a laser display system to make the structure of an x ray machine more compact.

A 2D or 3D velocity field is reconstructed from a cross-correlation analysis of image pairs of a sample, without first reconstructing images of the sample spatial structure. The method can be implemented via computer tomographic X-ray particle image velocimetry, using multiple projection angles, with phase contrast images forming dynamic speckle patterns. Estimated cross-correlations may be generated via convolution of a measured autocorrelation function with a velocity probability density function, and the velocity coefficients iteratively optimised to minimise the error between the estimated cross-correlations and the measured cross-correlations. The method may be applied to measure blood flow, and the motion of tissue and organs such as heart and lungs.

The invention discloses a frequency domain laser speckle imaging based blood flow velocity measuring method. The frequency domain laser speckle imaging based blood flow velocity measuring method comprises the following steps of illuminating laser beams on a measured object, imaging the measured object through an imaging system, collecting an original speckle image of the measured object through an image sensor, transferring dynamic speckle intensity with single pixel points being in a time domain of the collected original speckle image into a frequency domain, calculating the power spectral density, performing polynomial fitting on the power spectral density to obtain a smooth curve, transferring the smooth curve into the time domain through Fourier transform, calculating an autocovariance function of the pixel points and performing normalization, establishing a blood velocity measuring model, obtaining a relationship between the covariance function and the blood velocity and finally performing fitting to obtain a blood velocity value. The frequency domain laser speckle imaging based blood flow velocity measuring method has the advantages of not only eliminating static noise, improving the blood velocity measuring accuracy, avoiding influences from imaging environmental factors such as intensity and illumination angles and improving the measuring stability.

The invention discloses a dynamic speckle measurement method for the particle size and concentration change of turbid medium. The invention adopts the principle that when laser irradiates on turbid medium solution with dynamic change, dynamic speckles are formed in a forward scattering field and a backward scattering field, and the speckle size and contrast value of a dynamic speckle picture is in direct proportion with the particle size in the turbid media and in inverse proportion with concentration. Therefore, the particle size and concentration change in the turbid medium can be dynamically monitored in a real time mode by calculating the change of speckle size and contrast value of a dynamic speckle picture sequence. The method is a non-invasive type detection method, has the characteristics of simple operation and wide application range, and can be widely applied in the fields of medical biology, atmospheric environmental monitoring, underwater exploration, and the like.

The invention relates to a device and a method for measuring particulate motion of turbid media by using a dynamic speckle method. The device comprises a laser beam shaping contracting part, a forward scattering speckle field measuring part, a backward scattering speckle field measuring part, and a computer control and processing system. The method comprises the following steps: utilizing the device to record a forward scattering speckle field and a backward scattering speckle field generated by the particulate motion of turbid media and store the fields into the computer; according to the particle light scattering theory, choosing the forward scattering speckle field or backward scattering speckle field data; and analyzing the motion characteristic of the particulate, by utilizing a speckle chart characteristic value. The method is characterized by real time, dynamic and accuracy and can be widely applied to the fields such as medicaments, biology, life science, and the like.

The invention discloses a complete and high-resolution test method for the motion characteristics of particles in turbid media. The method comprises the following steps of: performing continuous, complete and real-time detection on the motion characteristics of the particles in the process of 'solution-colloid-sediment' of the turbid media by combining the resolution relation between the characteristic value of a speckle pattern and particle motion and utilizing a dynamic speckle test light path according to the particle light scattering theory; simultaneously, performing transient study on different critical points of the particle motion in the process by using a femtosecond laser test light path to perform the analysis of high spatial and temporal resolution on transient dynamics of the particles in the turbid media; and combining the two steps to realize the complete test with high spatial and temporal resolution characteristic on motion images of the particles in the process of 'solution-colloid-sediment' of the turbid media finally. The method is a non-contact, high-accuracy and real-time online detection method, has the characteristics that the operation is simple and the application range is wide, and can be widely used in the fields of medical science, pharmacy, chemical production and the like.

The invention relates to the technical field of laser display and discloses a method for eliminating laser display speckles and a laser source. The method comprises steps of: arranging multiple laser emission sources in an array, wherein the multiple laser emission sources have the same light emission direction and form a laser emission array; repeatedly enabling, at equal time intervals, a plurality of laser emission sources in the laser emission array to emit laser until the laser display speckles generated by the laser emission array are eliminated, wherein the number of the selected laser emission sources is a preset value, and the number of the selected laser emission sources at each time is not completely same. The method enables multiple laser emission sources in the laser emission array to emit laser in turns so as to eliminate the time coherence of the laser emission sources and continuously superpose the dynamic speckles, thereby gradually reducing the contrast of the speckles and finally eliminating the speckles. In addition, other optical devices are not arranged in an optical path so that the utilization rate of optical energy is increased and laser display quality is improved.

The invention provides a microscopic imaging method and system based on double-core optical fiber light control and dynamic speckle illumination. The method is characterized in that a light control part of the device is formed by oppositely installing two two-core optical fibers of which the output end surfaces are processed into specific angles. Laser beams are respectively coupled into a two-core optical fiber through a single-mode optical fiber, a focusing light field is formed near an output end face, and cells to be detected are stably captured. And the cells rotate around a specific axis by adjusting the output power of each fiber core of the other two-core optical fiber. And after the cells rotate to a certain angle and reach a stable state every time, a tomographic image of the cells is acquired by using a dynamic speckle illumination wide-field fluorescence microscopy technology, and finally a three-dimensional structure image of the cells is reconstructed. The system constructed by the invention can be used for obtaining a three-dimensional structure image with high temporal and spatial resolution of a living single cell, has the characteristics of simple structure, low cost, simplicity and convenience in operation and the like, and has wide application prospects in numerous research fields such as biology, medicine, life science and the like.

The invention disclose a dynamic speckle eliminating device for laser projection display, relates to the technical field of laser projection display, and aims at improving the speckle eliminating effect. The dynamic speckle eliminating device comprises a prism and a driving part, the prism includes first and second diffusing surfaces and a reflection surface, and a laser beam is input in the firstdiffusing surface, reflected in the reflection surface and finally output from the second diffusing surface; and the driving part drives the prism to vibrate according to a preset track and period. In the vibration process of the dynamic speckle eliminating device, the two diffusing surfaces generate different vibration tracks, so that the phase coherence of the laser beam is reduced greatly, anda better speckle eliminating effect is achieved. The dynamic speckle eliminating device is suitable for a laser projector.

The invention discloses a speckle elimination light path and a three-color laser projection system, which relate to the technical field of laser display. The three-color laser projection system comprises a reflective optical path assembly, a dynamic speckle elimination device and an optical rod, wherein the dynamic speckle elimination device comprises a diffusing component and a driving componentconnected with the diffusing component; and the reflective optical path assembly focuses a laser beam passing through the diffusing component to an inlet of the optical rod after at least one reflection. The light path turns for multiple times by means of the reflective optical path assembly, the functions of a plurality of dynamic speckle elimination devices are realized by means of only one dynamic speckle elimination device disclosed by the invention, and a good speckle elimination effect is achieved. The laser speckle elimination light path provided by the invention is simple in structure,the reflection or refraction and reflection combined light path design makes the structure of an optical machine more compact, and the miniaturization of the three-color laser projection system is easy to realize.

The invention discloses a high-brightness controllable pseudo-thermal light source based on liquid crystal light valve modulation, which comprises a pulsed laser, an adjustable beam expanding and collimating system, a polarizer, a first analyzer, an adjustable aperture diaphragm, a liquid crystal light valve, a second analyzer and a liquid crystal light valve control system. The pulsed laser, the adjustable beam expanding and collimating system, the polarizer, the first analyzer and the adjustable aperture diaphragm are arranged on the same optical axis. The optical axis is arranged on the incident light optical axis of the liquid crystal light valve. The second analyzer is arranged on the reflected light optical axis of the liquid crystal light valve corresponding to the incident light optical axis. Laser light output by the laser finally irradiates the liquid crystal light valve controlled by a liquid crystal light valve control system. Through controlling the liquid crystal light valve, a dynamic speckle field, i.e. a pseudo-thermal light field is obtained. The thermal fluctuation of the high-brightness controllable pseudo-thermal light source produced by the invention can be truly recorded by the photoelectric detection system of a limited transmission band, the cross spectrum purity conditions satisfying a true-thermal light field can be obtained through controlling RGB images loaded on the liquid crystal light valve and the pseudo-thermal light field produced at any time is controllable.

The invention discloses an optical vortices-based dynamic speckle test method. The optical vortices-based dynamic speckle test method comprises following steps: firstly, dynamic speckle sequential images of a dynamic changing process of an object is obtained; then the dynamic speckle sequential images are converted by a Laguerre-Gauss complex filter so as to obtain an optical vortices core structure parameter distribution matrix; and at last, quantitative analysis and measurement of the dynamic changing process are realized by using two novel characteristic factors, wherein the two novel characteristic factors are dynamic vortex survival rate and in-plane average speed of survival vortex. The optical vortices-based dynamic speckle test method is capable of realizing monitoring on dynamic random processes effectively, and is suitable for rapid changing and gradual changing processes, and quasi-static processes.

The invention provides a laser speckle contrast ratio measuring method. The method includes the following steps of setting a template length NT, wherein the template length NT represents the number of pixels participating in calculation of the method each time, the value of NT ranges from 1 to N, and N represents the total number of pixels of a measured laser field; calculating the average laser intensity and variance of pixel positions N(n) within the range of the template length NT, wherein n is equal to 1, 2, ..., N-NT+1, and the value of N(n) ranges from 1 to NT; calculating the dynamic speckle contrast ratio of a speckle image, wherein the speckle contrast ratio of the template length NT is the ratio of the standard deviation of the pixel positions N(n) to the average laser intensity of the pixel positions N(n); moving the position of a template without changing the template length NT, and repeating the steps to obtain a series of speckle contrast ratios. By means of the method, the contrast ratio of the whole frame of image can be dynamically reflected, the characteristics of speckles can be completely presented, and the estimation errors of laser display system indexes can be reduced as well.

The invention provides a dynamic speckle fluorescence microscopic imaging method and system based on four-core optical fiber light control. The device is characterized in that a light control part of the device is formed by mounting a four-core optical fiber of which the output end face is processed into a specific angle. A laser beam is divided into four beams through a beam splitter, the four beams are coupled into a four-core optical fiber through single-mode optical fibers respectively, a Bessel light field can be formed near the output end face, cells to be detected are stably captured, the output power of fiber cores of the optical fibers can be changed by adjusting a modulator, and the cells are made to rotate around a specific axis. And after the cells rotate to a certain angle and reach a stable state every time, a tomographic image of the cells is acquired by using a dynamic speckle illumination wide-field fluorescence microscopy technology, and a three-dimensional structure image of the cells is finally reconstructed. The constructed system has the advantages of being simple in structure, low in cost, easy to operate and the like, and has wide application prospects in many research fields such as biology, medicine and life science.

A high-brightness pulsed pseudothermal light source, which consists of a pulsed laser, a beam expander collimation system, a pinhole filter, an adjustable aperture stop, a frosted glass disc and a speed-regulating motor, the pulsed laser, beam expander The collimation system, the pinhole filter and the adjustable aperture stop are on the same optical axis, the pinhole filter is placed on the focal plane of the telescope of the beam expander collimation system, and the laser output from the pulsed laser Finally, it is irradiated on the frosted glass disk driven by the speed-adjusting motor to form a dynamic speckle field, which is the pseudo-thermal optical field. The thermal fluctuation of the pseudothermal optical field of the high-brightness pulsed pseudothermal light source of the present invention can be truly recorded by the photoelectric detection system with a limited passband, and is not affected by the passband of the photoelectric detection system used, meeting the requirements of the real thermal optical field Cross Spectrum Purity Conditions.

The invention relates to a character recognition system and method. One embodiment of the system comprises a light source, a digital micromirror array, a bucket detector and a computing device. The digital micromirror array converts light emitted by the light source into a dynamic speckle signal, and projects the dynamic speckle signal to the surface of a to-be-recognized target; the bucket detector receives a light intensity signal reflected by the to-be-recognized target; the calculation device performs second-order correlation calculation on the dynamic speckle signal and the light intensity signal to obtain a ghost imaging image of the to-be-recognized target; and inputting the ghost imaging image into a pre-trained character recognition model to obtain characters in a to-be-recognizedtarget. According to the embodiment, accurate recognition of the characters can be achieved with low cost.

The invention relates to the technical field of measuring devices, in particular to a double-sided dynamic shear testing device and method based on a Hopkinson pressure bar system, and the double-sided dynamic shear testing device comprises a rock sample, a testing device, a force application mechanism, a signal shear mechanism and a displacement shear mechanism, the force applying mechanism impacts a rock sample subjected to normal stress, and the displacement shearing mechanism collects dynamic change of the rock sample to obtain a dynamic speckle image and analyzes the dynamic speckle image to obtain a rock sample surface displacement field evolution law and a dynamic slip rate; an incident pulse signal, a reflection pulse signal and a transmission pulse signal which are generated when the force applying mechanism impacts the rock sample are acquired and analyzed through the signal shearing mechanism, so that incident energy, reflection energy and transmission energy are obtained; the problem that direct shearing of an existing dynamic shearing and friction measuring device based on the Hopkinson pressure bar cannot dynamically shear a rock structural surface under the action of medium-high strain rate dynamic load is solved.

The invention provides a wide-field multispectral fluorescence microscopic imaging method and system based on dynamic speckle illumination. The system is characterized in that a mode-locked titanium sapphire femtosecond pulse laser is used as a light source. A femtosecond laser pulse with a wide spectral range forms a speckle pattern after passing through a scatterer, full-field illumination is formed in the field of view of the microscope objective, and different types of fluorophores in a biological sample to be detected are excited at the same time. Illumination speckle patterns are sequentially changed, a CCD camera detects and receives fluorescence images obtained through illumination of the dynamically-changed speckle patterns, and the wide-field multispectral fluorescence microscopic imaging method based on dynamic speckle illumination is achieved through a tomography extraction algorithm. The system constructed by the invention can simultaneously and quickly acquire three-dimensional space distribution images of different types of fluorophores in a biological sample, has the characteristics of high temporal and spatial resolution, simple structure, easiness in operation and the like, and has wide application prospects in the research fields of biology, medicine, life science and the like.

The invention discloses a computational correlation imaging denoising method and a system based on dynamic speckle field. The method comprises the following steps of substituting a fixed light intensity modulated signal with a frame in a digital micromirror modulator original light intensity modulated signal sequence; according to the substituted light intensity modulated signal, modulating the coherent light emitted by a laser into incoherent light, and using the modulated incoherent light to illuminate the object to linearly estimate the change of the noise and further recover the signal ofthe reflected light intensity of the real object; finally, reconstructing a image of the object to be measured by calculating and correlating the signal of the reflected light intensity with the lightintensity modulated signal of the incoherent light. The computational correlation imaging denoising method or system based on dynamic speckle field of the present invention is capable of resisting the effects of dynamic interference in associated imaging.