39 results about "Phase function" patented technology

The invention discloses a super-resolution imaging system and a super-resolution method based on phase coding, which are used for improving the imaging resolution and the imaging signal-to-noise ratio of a visible light imaging system. The system is composed of an imaging main lens 1, a first 4f relay lens 2, a phase mask plate 3, a second 4f relay lens 4, a camera 5 and an electric rotating table 6, and a system transfer function has anisotropy on a certain frequency component by optimally designing a phase function of the phase mask plate. The phase mask plate 3 is controlled to rotate and regulate through the electric rotating table 6, a series of coded low-resolution images are collected through the camera 5, combined constraint iteration of the spatial domain and the frequency domain is combined, the collected images are reconstructed until algorithm convergence is achieved, and a reconstructed image breaking through Nyquist sampling is obtained. Compared with the method based on intensity mask coding, the method has the advantages that anisotropy regulation and control of the point spread function can be realized under the condition that luminous flux is not lost, and the imaging resolution is improved by more than 2.5 times.

The invention relates to the technical field of optical application, and discloses a method for shaping Gaussian light into a linear light beam based on an analytical method, which comprises the following steps: S1, establishing a mathematical model of an input Gaussian light beam and an output linear light beam, and determining a relationship between a shape parameter of the output linear light beam and Uout (x, y), S2, deducing a phase compensation function, the method comprises the following steps: S1, deducing a phase compensation function which needs to be loaded by an SLM by means of an analytical method, S3, loading the phase function to the SLM, and checking the accuracy of phase modulation by using the characteristic that the SLM modulates a light beam phase, and S4, shaping and verifying the light beam. According to the method, the phase pattern can be accurately calculated according to the specific light beam parameters and the target shape, and the method has better universality. Corresponding phase patterns can be calculated through an analytical method for Gaussian beams with different wavelengths and waist radiuses or linear beams with different widths, lengths and light intensity distribution requirements, and the phase patterns are loaded to the SLM, so that efficient and accurate beam shaping is realized.

The invention discloses a periscope head image difference compensation method and system, a computer and a storage medium, a periscope head comprises a reflecting prism, a lens group and a diffractive optical element, and the non-reflecting surface of the reflecting prism is provided with a polarization coating; the method comprises the following steps: constructing an optical path model according to design requirements of a periscope lens module, and carrying out aberration analysis on the optical path model; calculating a chromatic aberration compensation phase function of the diffractive optical element according to a chromatic aberration compensation formula; calculating a spherical aberration compensation phase function of the diffractive optical element according to a spherical aberration expansion formula; and calculating a total phase function of the diffractive optical element, and performing aberration compensation on the optical path model according to the total phase function. According to the long-focus periscope lens module, the total aberration of the periscope lens module can be compensated by utilizing the cooperation of the diffractive optical element and the reflecting prism with the polarization coating, so that the size of the long-focus periscope lens module is reduced, and the imaging quality of the long-focus periscope lens module is improved.

The invention provides a slit-type spectral imaging method based on filtering phase reconstruction and a grating spectrometer. The method comprises the following steps: measuring wavefront aberration of a slit-type grating imaging spectrometer before slit filtering by using a wavefront sensor; based on a slit filtering principle, reconstructing a phase function after slit filtering by using wavefront aberration before slit filtering; and capturing a slit image, and reconstructing the slit image by using the reconstructed filtered phase function of the slit to obtain a final reconstructed image. According to the method, effective recovery of the slit imaging data of the grating spectrometer based on the slit is realized, the influence of optical aberration and image noise on the spectrum and spatial resolution of the spectrometer is effectively eliminated, and the slit imaging quality is remarkably improved and is close to the diffraction limit.

The invention provides a particulate matter physical property determination method based on Mie scattering, and relates to the technical field of particulate matter physical property measurement, and the method comprises the steps: generating and capturing a single particle; performing lateral scattering phase function imaging and interference correction backscattering phase function imaging on the particles; respectively extracting each imaging result to obtain a first gray value distribution curve and a second gray value distribution curve; calculating lateral off-sphere scattering electric field distribution and interference correction back off-sphere scattering electric field distribution of the particles under different particle physical characteristic values; determining first and second light intensity distribution curves of the particles; determining the distance between the gray value distribution curve and the light intensity distribution curve which correspond to each other; determining a target distance meeting a corresponding condition in all the distances; taking a particle physical characteristic value corresponding to the target distance as a candidate physical characteristic value of the captured particle; and determining the physical characteristic value of the captured particles according to all candidate physical characteristic values. The invention aims to reduce the measurement cost of the physical characteristics of particles.

The present invention discloses a fracture weakness parameter inversion method, comprising the following steps: S1: acquiring 3CVSP data of a target study area, and processing to obtain an upgoing S1 wave and an upgoing S2 wave; S2: obtaining the P wave velocity and the S wave velocity of the overlying stratum above the target layer according to the first arrival waves of the P wave and the S wave in the logging data and the 3CVSP data; S3: calculating and obtaining the travel time of the target layer at different detectors; S4: picking up the phase axis one closest to the target layer in the upgoing S1 wave according to the travel time, and obtaining the observed PS1 propagation time; S5: using the upgoing S1 wave, extracting the phase axis two of the target layer in the upgoing S2 wave through waveform matching, and obtaining the observed PS2 propagation time according to the travel time corresponding to the phase axis two; S6: establishing an objective function based on the observed PS1 propagation time and the observed PS2 propagation time, and inverting and obtaining the fracture weakness parameter according to the objective function. The present invention can accurately invert the fracture weakness parameter using the propagation time of the PS1 wave and the PS2 wave.

A method for multifocal energy gradient laser holographic cutting of hard and brittle materials includes the following steps: S1, determining the parameters of the incident beam and the high numerical aperture focusing objective; S2, determining the three-dimensional multifocal beam and parameters of the target hard and brittle material; S3, setting a two-dimensional linear phase distribution on the spatial light modulator plane as the initial phase for subsequent iterative calculations; S4, establishing a forward-backward propagation iterative loop based on phase optimization to calculate the multifocal holographic phase distribution; S5, superimposing a linear blazed grating phase on the multifocal holographic phase distribution, and generating a composite diffraction phase hologram using MATLAB code and inputting it into the spatial light modulator; achieving uniform holographic cutting with consistent actual absorbed energy in each layer. This invention features controllable three-dimensional focal positions, adjustable energy gradients along the depth direction at each focal point, strong deep-layer energy compensation capability, simultaneous aberration correction, and high consistency in cutting at different depths.

The invention relates to a focus depth controllable Gaussian-Bessel beam generation method, a focus depth controllable Gaussian-Bessel beam generation device and a storage medium, and belongs to the technical field of laser processing. In the optimization process, a standard axicon phase corresponding to a target non-diffraction propagation length is introduced as a fixed initial value, the problems of slow convergence and uncontrollable focal depth caused by a random or zero initial value in a traditional method are avoided, rapid, flexible and controllable focal depth is realized, and by obtaining the actually measured light intensity along the optical axis direction, the target non-diffraction propagation length is optimized. Compared with numerical simulation light intensity point by point, a difference field matrix is constructed and fed back to an optimization process to iteratively update a phase function, so that not only is the uniformity of axial intensity improved, but also attenuation caused by tail energy collapse and environmental noise under a long focal depth condition is effectively inhibited, and the method has high robustness and practicability. The technology is suitable for scenes with extremely high requirements on uniformity and focal depth, such as laser precision processing, long focal depth microscopic imaging, optical communication and the like.

The invention discloses a three-dimensional optical focus regulation and control device, and relates to the technical field of micro-nano optics. The three cascaded metasurfaces are arranged to be capable of relatively rotating and moving, and the three metasurfaces have the synergistically designed phase distribution functions, so that decoupling control of axial focus change and transverse focus offset is realized. Specifically, a complementary rotation pair is formed by a second metasurface and a third metasurface, and the relative rotation of the second metasurface and the third metasurface is used for adjusting an axial focus and inhibiting aberration (such as coma and astigmatism) introduced by a lateral offset term at the same time; the relative rotation of the first metasurface and the second metasurface mainly regulates and controls an angular phase item to realize the lateral offset of a focus; due to the fact that the phase function is designed to be separable in angular modulation and radial modulation, controlled focuses can transversely move and axially move through different rotation pairs, and independence of the two control modes, namely decoupling regulation and control, is achieved.

The invention discloses a surface structure design method of a super-structure surface device. The surface structure design method comprises the following steps: (1) obtaining a phase dispersion value corresponding to a super-structure atom; (2) designing a phase function of the device; (3) performing iterative optimization according to the phase function and the phase dispersion value of the super-structure atoms to obtain optimized phase bias terms and super-structure atom arrangement; (4) obtaining corresponding actual physical parameters according to the obtained meta-structure atom arrangement, then comparing the actual physical parameters with design target parameters to analyze errors, and when the errors meet requirements, outputting a current phase bias item and current meta-structure atom arrangement; otherwise, updating the function item, and returning to the step (2). According to the invention, various metasurface dispersion devices can be flexibly designed, and the method provided by the invention can obtain relatively high far-field diffraction efficiency. And secondly, the method is suitable for dispersion design of continuous bandwidth and discrete wavelength. And thirdly, the feasibility of the invention is not limited by the central wavelength of the device, but is suitable for any electromagnetic wave band.

The present disclosure refers to an encoding method for quantum key distribution, the method being carried out in a transmitter device (11) having a classical processor (11a) and means for preparing and transmitting quantum signals, the method comprising: generating an encoder initial bit sequence; generating, from the encoder initial bit sequence, a quantum signal comprising a plurality of optical pulses, wherein generating each optical pulse of the plurality of optical pulses comprises at least one of: modulating an intensity profile of the optical pulse according to an intensity function which depends on a time and on a first encoder value of at least one first bit of the encoder initial bit sequence; and modulating a phase profile of the optical pulse according to a phase function which depends on a time and a second encoder value of at least one second bit of the encoder initial bit sequence; transmitting the plurality of optical pulses to a receiver device (12) via a quantum channel (10a); and determining a shared key shared between the transmitter device (11) and the receiver device (12) from the encoder initial bit sequence by classical post-processing and at least one of transmitting classical information to the receiver device (12) and receiving further classical information from the receiver device (12). Further, a decoding method, a method, a transmitting device (11), a receiver device (12), and a system are disclosed.

In a three-dimensional (3D) display, a display panel having an array of subpixels may display an image according to stereo mapping coordinates associated with a viewer. A periodic optical element may direct light from the display panel to the viewer. The periodic optical element may be invariant along an optical axis having a slant angle relative to the display panel. A viewer tracker may determine a location of the viewer. The stereo mapping coordinate of a selected subpixel of the array of subpixels may be a function of the location of the viewer, a location of the selected subpixel, a phase function of the periodic optical element, a separation between the periodic optical element and the display panel, and a refractive index of a material disposed between the periodic optical element and the display panel.

The invention relates to a method and system for quantum key distribution. An encoding method for quantum key distribution, the method being performed in a transmitter device (11) having a classical processor (11a) and means for preparing and transmitting quantum signals, the method comprising: generating an encoder initial bit sequence; according to the encoder initial bit sequence, generating a quantum signal comprising a plurality of optical pulses, generating each of the plurality of optical pulses includes at least one of: modulating an intensity profile of the optical pulse according to an intensity function of a first encoder value dependent on time and dependent on at least one first bit of the encoder initial bit sequence; and modulating a phase curve of the optical pulse according to a phase function dependent on time and a second encoder value of at least one second bit of the encoder initial bit sequence; transmitting a plurality of optical pulses to the receiver device (12) via the quantum channel (10a); and determining a shared key shared between the transmitter device (11) and the receiver device (12) according to the encoder initial bit sequence by at least one of classic post-processing and transmitting classic information to the receiver device (12) and receiving another classic information from the receiver device (12). Further, a decoding method, a method, a transmitting device (11), a receiver device (12) and a system are disclosed.

The present application relates to the technical field of target detection, in particular to a target infrared polarization characteristic model construction method based on Monte Carlo method, comprising: S1, determining the position, scattering angle and azimuth angle of the scattered photon according to the propagation distance of the photon, the initial Stokes vector of the photon, the Mueller matrix and the phase function of the incident light when the photon occurs scattering; S2, updating the new Stokes matrix after the elastic interaction of the photon according to the rotation matrix and the initial Stokes vector; S3, updating the direction cosine of the scattered photon. The present application can construct a model for simulating the infrared polarization characteristics of the target.

The present invention discloses a method for simulating the optical pulse response of an underwater wireless optical channel, which includes the following steps: calculating the seawater backscattering probability according to the actually measured seawater parameters; calculating each coefficient in the scattering phase function expression according to the backscattering probability; calculating the root mean square of the scattering angle according to the scattering phase function; calculating the optical pulse transmission delay of the underwater wireless optical channel according to the root mean square of the scattering angle; and obtaining the optical pulse response waveform of the underwater wireless optical channel according to the transmission delay. The present invention combines the photon small-angle approximation scattering model with the TTHG scattering phase function, which can effectively reduce the computational complexity while considering the influence of backscattering on the optical pulse response of the underwater wireless optical channel, making the result as close to the actual situation as possible.

The invention discloses a double-reflector antenna electromechanical coupling rapid analysis method and system, and aims to reconstruct a physical optical integral expression. Dispersing the reflecting surface into triangular grids, and performing linear fitting on amplitude and phase functions in each grid; an equivalent wave number / wavelength concept is introduced, a phase fitting error is analyzed, a differentiated grid processing strategy is put forward, a closed expression for calculating a far-field directional diagram is deduced through affine transformation and partial integration, and numerical integration is replaced by analytical calculation; and converting the structural deformation into an additional phase error, and integrating the additional phase error into a rapid calculation framework. The method breaks through the limitation of the traditional electromagnetic analysis on the grid size, greatly improves the electromechanical coupling analysis speed on the premise of guaranteeing the precision, and provides an efficient tool for the design and profile compensation of a high-frequency-band antenna.

The present application relates to the technical field of light scattering characteristic calculation, and particularly relates to a method for calculating the transmission characteristic of light in a multi-particle Mie scatterer, comprising: Mie particle scattering phase function calculation: according to the scattering particle density, the scattering particle size and the particle refractive index, the coefficients of Mie scattering are calculated to obtain the Mie scattering phase function; the propagation mode of light is analyzed through the Mie scattering phase function; multi-particle Mie scattering calculation: an equivalent free path is defined; after scattering, the probability of particle collision is calculated; according to the probability, a particle is randomly sampled from the particles, the phase function corresponding to the selected particle is used for angle sampling, the new direction cosine is calculated by using the angle and the original direction cosine, and the direction of the photon is updated; the process is repeated until the light propagates out of the scatterer. The method has the advantages that the scattering behavior is processed through a unified calculation framework, the modeling efficiency and the application range are improved while the physical consistency is ensured.

The invention relates to the technical field of light scattering characteristic calculation, in particular to a method for calculating transmission characteristics of light in a multi-particle Mie scatterer. Comprising the following steps: calculation of a Mie particle scattering phase function: calculating a Mie scattering coefficient according to scattering particle density, scattering particle size and particle refractive index to obtain the Mie scattering phase function; analyzing the propagation mode of the light through a Mie scattering phase function; calculation of multi-particle Mie scattering: defining an equivalent free path; after scattering occurs, the collision probability of the particles is calculated; randomly sampling from the particles according to the probability, performing angle sampling by using a phase function corresponding to the selected particle, calculating a new direction cosine by using an angle obtained by sampling and an original direction cosine, and updating the direction of the photon; and repeating until the light is transmitted out of the scatterer. The method has the advantages that scattering behaviors are processed through a unified calculation framework, the modeling efficiency is improved while physical consistency is guaranteed, and the application range is widened.

The invention discloses a spiral elliptical lens and a preparation method thereof, and relates to the field of vortex beams, and the spiral elliptical lens is obtained by modifying a hyperbolic lens phase through an elliptical polar coordinate equation and then superposing a spiral phase. The preparation method comprises the following steps: step 1, determining polar coordinate equation parameters of an ellipse; 2, the focal length and the wave number of the modified hyperbolic lens are designed; 3, designing a spiral phase function; step 4, superposing the phase of the modified hyperbolic lens and the spiral phase to obtain the height morphology of the processing material; and 5, carrying out selective polymerization on the processed material according to the height morphology. The spiral elliptic lens designed by the invention can efficiently generate an elliptic perfect vortex beam at any designed focal length; and meanwhile, the miniaturization of the spiral elliptic lens is realized by utilizing the high-precision processing capability of the femtosecond laser direct writing technology, so that the application of the device in a micro-optical system and integrated optics is facilitated.

A method for quantum key distribution includes generating an encoder initial bit sequence; generating a quantum signal comprising optical pulses by modulating an intensity profile of the optical pulses according to an intensity function depending on a time and on a first encoder value of at least one first bit of the encoder initial bit sequence, and / or modulating a phase profile of the optical pulse according to a phase function which depends on a time and a second encoder value of at least one second bit of the encoder initial bit sequence; transmitting the plurality of optical pulses to a receiver device via a quantum channel; and determining a shared key shared between the transmitter device and the receiver device from the encoder initial bit sequence by classical post-processing and at least one of transmitting classical information to the receiver device and receiving further classical information from the receiver device.

The application provides a 3DGS re-illumination method and system based on light absorption rate calculation and volume light, and belongs to the technical field of three-dimensional scene rendering. The application is aimed at 3DGS re-illumination of high-temperature scenes, obtains a 3DGS Gaussian point set, a temperature distribution and a light source camera position of a scene, and constructs a refractive index gradient field from temperature data. A probe light ray is emitted from a light source to a target Gaussian point, a refractive index vector of each sampling point is obtained through step sampling and interpolation, the curvature of the light ray is calculated, and the real incident direction of each Gaussian point on the propagation path is determined. The forward scattering coefficient is determined according to the ratio of the Gaussian point particle diameter to the light source wavelength, the spatial angle between the incident direction and the observation direction is combined, the anisotropic light absorption rate is calculated by using the scattering phase function. Finally, the transmittance is determined according to the light absorption rate of all Gaussian points on the path, and the color is modulated to realize re-illumination rendering. The application realizes physically accurate 3DGS volume light re-illumination rendering in a high-temperature gradient scene.

The invention provides an annular flat-topped beam optimization method based on an improved GS algorithm, and the method comprises the steps: multiplying amplitude distribution with a phase function through employing the diffraction effect of a binary optical element, obtaining the complex amplitude distribution of a light field, and representing the diffraction effect through Fourier transform, the energy conversion efficiency of an actual shaping light beam and a target annular flat-topped light beam is calculated in real time in the algorithm iteration process and compared with a preset threshold value, the phase distribution of an optimal binary optical element is obtained, and a Gaussian light beam is shaped into a hollow annular flat-topped light beam. According to the method, the problems that a traditional algorithm is sensitive to an initial phase and a convergence path easily deviates from an optimal solution are solved, it is ensured that the output beam has a higher energy utilization rate while meeting the amplitude distribution requirement, and the stability and practicability of annular flat-topped beam shaping are effectively improved.

The application discloses a microstructure multilayer material recovery method and system, comprising the following steps: constructing a multilayer microstructure material model based on SpongeCake, regarding each layer of material as a volume medium, and there is no interface between layers; the optical properties of each layer of medium are determined by a phase function; taking the material parameters and maps of each layer of medium as input values of the multilayer microstructure material model based on SpongeCake; rendering the multilayer microstructure material model based on SpongeCake, and the multilayer microstructure material model based on SpongeCake outputs a three-dimensional rendering image; calculating a loss function between the three-dimensional rendering image and a camera shooting image in the rendering process, using an optimizer to update the material parameters of each layer of medium according to the loss function value, gradually approximating the real material parameters, and outputting the material parameters of each layer of medium when a set number of iterations is reached, so that a simulation material model of a real multilayer microstructure material sample is obtained.

Provided is an imaging system including a phase mask including a phase modulation meta surface coded with an image reconstruction phase function configured to reconstruct an image, the image reconstruction phase function being obtained by adding a first phase function corresponding to a lens phase to a second phase function which is a random function, and an image sensor configured to convert light, transmitted through the phase mask from an object, into an electrical signal.

The invention provides a method for an object to project a soft shadow in a volumetric fog environment, and relates to the technical field of computer images, and the method comprises the steps: carrying out the volumetric fog generation of a built rendering scene, obtaining a target scene, and determining a target distance from a shadow pixel point to an upper shielding object; determining a phase scattering parameter value range corresponding to the shadow pixel point according to the target distance and the illumination intensity; determining the maximum scattering angle corresponding to the shadow pixel point based on the phase scattering parameter value range and the phase function texture; determining a sampling range corresponding to the shadow pixel point according to the target distance and the maximum scattering angle; determining the soft shadow intensity grade of the shadow pixel point according to the depth information of the sampling pixel point in the sampling range; and performing shadow synthesis rendering on the target scene according to the respective soft shadow intensity levels of all shadow pixel points. The objective of the invention is to improve scene rendering credibility.

A design method of an achromatic fast hyperspectral zoom imaging system without focusing comprises the following steps: S1, establishing a light field function of a hyperspectral imaging system based on physical optics and Fourier optics theories; s2, for a diffractive optical element DOE, determining a basic surface shape, a phase function and optimizable parameters, and combining a neural network to design a super depth-of-field function; s3, for the MOIRE, determining a basic surface shape, a phase function, an optimizable parameter and a system target zoom ratio, and designing an optimizable parameter range in combination with a zoom principle; and S4, establishing a neural network for end-to-end collaborative design of the deep learning-based optical element group (DOE + MOIRE)-hyperspectral reconstruction network. And S5, designing a loss function suitable for the end-to-end collaborative design neural network of the optical element group-hyperspectral reconstruction network, and realizing achromatic hyperspectral zoom imaging. The technical effects are that DOE with a super depth-of-field function and MOIRE surface shape design of rotary zooming are realized, and achromatic fast hyperspectral zooming imaging without focusing is realized by cooperating with a reconstruction network.

The application discloses a light field regulation method, a wave aberration detection system and a method for a reflective objective. It relates to the technical field of image processing and optical engineering. The application designs a two-dimensional Gaussian angular spectrum homogenization phase function and a one-dimensional grating phase function, constructs a total composite phase function through linear weighted fusion. The total composite phase function is iteratively optimized through an optimization objective function, and the phase distribution of the MCGH element is obtained, so that the light field regulation is performed through the MCGH element containing the phase distribution. Further, the wave aberration detection system and the method for the reflective objective containing the MCGH element are also disclosed. The application composites the pupil homogenization and spatial modulation functions on a single microstructure surface, solves the problems of low integration degree, alignment error sensitivity and difficulty in adapting to structured illumination of traditional discrete elements, and realizes high-precision and high-robustness in-situ wave aberration detection for any reflective high-NA optical system.

The invention relates to a personalized aberration compensation and depth-of-field fusion type implantable contact lens based on calculation optical wavefront regulation and control, and belongs to the crossing field of ophthalmic medical instruments and calculation optics. A composite wavefront regulation and control structure is formed on at least one optical surface of an optical area of a lens main body of the contact lens; a target phase function corresponding to the composite wavefront regulation and control structure is a two-dimensional function and at least comprises an aberration compensation phase term used for compensating wavefront aberration of a target eyeball and a depth-of-field extension phase term used for generating an extension focal depth; the target phase function is determined through a computational optical reverse optimization method, the optimization process aims at improving the imaging quality of the eyeball-ICL combined optical system under a plurality of preset object distances, and meanwhile, the expected positioning error of the ICL relative to the pupil is used as a robustness constraint condition. The problems of individualized aberration correction and continuous depth-of-field expansion are solved, and a novel ICL solution with high visual quality, high clinical robustness and manufacturability is provided.

Disclosed in the present invention are a phase encoding-based super-resolution imaging system and a super-resolution method, used for improving the imaging resolution and imaging signal-to-noise ratio of a visible light imaging system. The super-resolution imaging system consists of a main imaging lens, a first 4f relay lens, a phase mask, a second 4f relay lens, a camera, and an electric rotating stage. By optimizing a phase function of the phase mask, a transfer function of the super-resolution imaging system has anisotropy on a certain frequency component. The electric rotating stage controls the rotation regulation of the phase mask and the camera captures a series of encoded low-resolution images. By mean of joint spatial- and frequency-domain constraint iteration, the captured images are reconstructed until an algorithm converges, so as to obtain reconstructed images that break through Nyquist sampling. Compared with being based on intensity mask encoding, the method can implement the regulation and control of the anisotropy of a point spread function without losing luminous flux, thereby achieving an imaging resolution improvement of more than 2.5 times.

The present application relates to a PCB hole positioning method, device, equipment, and medium. The method comprises: sequentially projecting four grating fringe images onto a flat plate where the hole to be positioned is located, and collecting the reflected grating fringe images formed by each grating fringe image on the flat plate where the hole to be positioned is located. Determining two wrapped phases in the modulated light phase of the reflected grating fringe image; unwrapping the two wrapped phases in the reflected grating fringe image to obtain the phase information of the flat plate where the hole to be positioned is located; determining the three-dimensional coordinate set of the flat plate where the hole to be positioned is located based on the phase information of the flat plate where the hole to be positioned is located, and the correspondence between the three-dimensional coordinates and the phase; and filtering out the three-dimensional coordinates of the edge points of the hole to be positioned from the three-dimensional coordinate set to determine the position of the hole to be positioned. This method can determine the three-dimensional coordinates of the hole to be positioned by projecting four grating fringe images, without the need to obtain another phase function through other measurement methods, thereby improving the alignment speed of the PCB hole.