42 results about "Complex amplitude" patented technology

The invention relates to a high-resolution wavefront measurement method and device for a complex light field, electronic equipment and a storage medium, and the method comprises the steps: obtaining an observation image representing the to-be-measured wavefront intensity distribution based on to-be-measured light waves passing through a scattering sheet; obtaining initial complex amplitude space distribution corresponding to the wavefront to be measured based on the observation image; and inputting the initial complex amplitude space distribution and the observation image into a target function, taking the complex amplitude space distribution under the condition that the numerical value of the target function is minimum as the complex amplitude space distribution corresponding to the wavefront to be measured, and performing wavefront inversion by minimizing the target function to obtain the wavefront to be measured. The objective function comprises a data fidelity term, a spatial smoothness constraint term and a spatial spectrum bandwidth constraint term of the wavefront to be measured. And for a complex light field with strong aberration, turbulent flow or high-order singular points, the high-resolution wavefront is quickly reconstructed. Object information recording and imaging can be supported under the defocus condition, and the method is further suitable for application requirements of rapid and high-throughput detection and the like.

This invention belongs to the field of coaxial holographic reconstruction and discloses a holographic reconstruction method based on a wavelet domain feature correlation complex-valued neural network. Specifically, the method involves: adding a phase term to the coaxial hologram A to construct a complex amplitude B, and performing an n-level discrete wavelet transform on it. The transformed result and the complex amplitude B are used as inputs to the complex-valued neural network, outputting the object field complex amplitude C. Next, noise suppression is applied to the object field complex amplitude C, and the suppressed complex amplitude D is used to simulate the forward propagation process of coaxial holography to generate a hologram E. Finally, the similarity between coaxial hologram A and hologram E is calculated, and a smoothing total variational constraint is applied to the phase of the complex amplitude D. Holographic reconstruction is achieved through a gradient descent optimization algorithm of the complex-valued neural network. This invention aims to utilize the inherent coupling relationship between the wavefront amplitude and phase terms in optical holography to construct a complex-valued feature correlation model to separate the target object from the background information, preserving target features while suppressing noise, thus achieving superior holographic reconstruction.

The application discloses a motor rotor dynamic balance test system and method, comprising: arranging an acceleration sensor and an encoder, collecting vibration, angular position signal and current signal; establishing a multi-resonance phase-locked loop, outputting a de-bouncing phase and an angular position sequence, forming a phase reference; angular domain resampling and sparse harmonic decomposition, extracting complex amplitude and generating observation and working condition data; complex value reversible flow model reverse mapping, combining constraint processing, outputting target counterweight instruction; target counterweight instruction injection virtual correction, calculating vibration decline rate, dynamically optimizing counterweight instruction; physical correction and recheck, archiving working condition label, counterweight instruction and recheck result after passing. The application realizes intelligent detection and correction of motor rotor dynamic balance by fusing multi-resonance phase-locked loop and complex value reversible flow model, and is free of test weight, high in precision and capable of multi-working condition.

The invention discloses a construction method of a non-acceleration PST Airy wave packet, and relates to the technical field of non-diffraction beams. The method comprises the following steps: defining Lorentz acceleration of a light beam in a PST domain; lorentz acceleration is applied to the light beam of the PST domain parabola-shaped frequency spectrum; superposing a cubic phase on the parabolic frequency spectrum of the PST domain; a non-acceleration PST Airy wave packet is generated by using a complex amplitude modulation method based on a spatial light modulator. Compared with a space-time light pulse scheme needing a pulse laser source, a 4f pulse shaping system and a complex field scanning device, the method achieves efficient generation of the wave packet through simplified configuration.

The invention relates to the technical field of distortion correction, and discloses a laser imaging wavefront distortion correction system and method based on deep learning, and the system comprises a first module which collects three intensity images; the second module is used for estimating the Zernike coefficient and the amplitude of the target complex amplitude; the third module is used for constructing a loss function; a fourth module that calculates an actuator voltage; the fifth module is used for calculating the Stell ratio and the high-frequency lifting ratio in the modulation transfer function; and the sixth module is used for re-applying the voltage of the actuator when judging that the evaluation condition is not met. According to the method, a full-process correction mechanism is constructed by integrating deep learning and an optical physical rule, and initial correction is realized by stably solving the voltage of the actuator by utilizing Tagunov regularization, so that the high-frequency detail definition in imaging is improved, the correction accuracy, real-time performance and robustness are both considered, and the method is suitable for large-scale popularization and application. And the application suitability of the laser imaging technology in the high-precision field is greatly expanded.

The invention belongs to the technical field of high-precision morphology measurement, and discloses an automatic refocusing large-measurement-range nano-morphology measurement method, which comprises the following steps of: 1, acquiring a spectral interference signal of a sample by using an OCT (Optical Coherence Tomography) system, and performing one-dimensional inverse Fourier transform on the signal in a wavenumber domain to obtain an airspace complex amplitude signal; step 2, selecting a surface complex amplitude signal according to the maximum signal intensity based on the airspace complex amplitude signal; step 3, calculating average low-frequency intensity based on the surface complex amplitude signal to obtain an actual defocusing distance; 4, performing refocusing calculation based on the surface complex amplitude signal and the actual out-of-focus distance to obtain a refocusing surface signal; and step 5, based on the refocusing surface signal, calculating and outputting a morphology height difference. According to the method, the effective measurement range of OCT nano-morphology detection can be expanded, the morphology detection capability of a non-flat surface is optimized, side lobe artifacts caused by defocusing are inhibited, the method is realized based on numerical calculation, and the system complexity and cost are reduced.

The invention discloses an Airy beam generation method and device. The method comprises the following steps: S1, determining a working frequency and constructing the device; s2, establishing a corresponding relationship between the geometric parameters of the leaky wave unit and the leaky wave phase and amplitude; s3, solving one-dimensional Airy beam complex amplitude distribution; s4, reversely solving unit geometric parameters to realize target complex amplitude regulation and control; and S5, constructing the metasurface complex amplitude regulation and control device based on the one-way electromagnetic mode. According to the invention, the size of the metal block and the thickness of the air dielectric layer are independently regulated and controlled, so that complex amplitude regulation and control of transmission waves in a free space are realized; the metasurface device is simple and convenient in structural design, high in efficiency, easy to integrate and reconfigurable, can replace a spatial light modulator through a one-way waveguide phase regulation and control function, reduces the system cost, improves the integration level, and is suitable for on-chip integrated efficient free space wavefront control application.

The invention discloses a four-focus long-focal-depth broadband achromatic superlens design based on an improved weighted GS algorithm, and belongs to the field of micro-nano optics. The super lens comprises a silicon dioxide substrate and a titanium dioxide cylindrical nano column array. In the initial iteration stage of the GS algorithm, focusing and axicon superposition phases are adopted to construct a complex amplitude field, and a dynamic amplitude weighted feedback mechanism is introduced. According to the design, four off-axis focuses with highly uniform energy are realized on a target focal plane, and focal length drift caused by broadband dispersion is covered by using an expanded super-long focal depth. Simulation shows that within the range of 640-740 nm, the average focal depth of the device reaches 6.33 microns, the focus intensity deviation is smaller than 5%, the average focusing efficiency is 62.47%, and broadband achromatic focusing is effectively achieved. The method has a wide application prospect in the fields of parallel laser processing, high-throughput imaging and the like.

This invention proposes a low-noise holographic 3D display method based on a fractional Fourier transform algorithm. The method includes the following steps: First, setting the signal and noise intervals of the recorded object to obtain a preprocessed image RD(X,Y); Second, superimposing the image RD(X,Y) with a quadratic phase generator to produce a corresponding complex amplitude distribution D0(X,Y) on the object plane; then, performing a fractional Fourier transform based on the complex amplitude distribution D0(X,Y) on the object plane to obtain a complex amplitude distribution D1(X,Y) on the holographic plane; extracting the phase information of D1(X,Y) and... The complex amplitude distribution D2(X,Y) of the object plane is obtained through fractional-order inverse Fourier transform. A double constraint of amplitude and second-order phase is applied to the signal interval of D2(X,Y) to obtain the complex amplitude distribution D3(X,Y) of the object plane, completing the first iteration. The complex amplitude distribution D3(X,Y) is then used to replace D0(X,Y) to start the next loop, continuing until the phase converges to the optimal solution. In the third step, the phase distribution of the optimal solution is extracted to generate a pure phase hologram. By superimposing pure phase holograms of different depths, the final pure phase hologram of the 3D object is obtained. Low-noise holographic 3D display is achieved by illuminating the pure phase hologram of the 3D object with coherent light.

The application discloses a mode purity measurement method of a few-mode ring core fiber based on principal component prior information. First, all spatial modes supported by the few-mode ring core fiber to be measured are calculated to determine the highest order; second, a nonlinear equation set connecting the fiber output intensity mode spot and the complex amplitude of each spatial mode is listed, and an algorithm for solving the equation set by using the principal component order prior information is designed, so that the recovery of the complex amplitude of each mode and the measurement of the principal component mode purity are realized. Then, an optical device for detecting the fiber exit mode field is built. For the fiber near-field intensity mode spot at any time, the prior information of the principal component order is obtained through an interference pattern or the shape of the intensity mode spot, and the measurement of the mode purity can be realized by applying the above-mentioned algorithm. The application can accurately recover the mode purity of the few-mode ring core fiber from the fiber output near-field intensity mode spot only, and has strong applicability.

The application provides a line spectrum estimation method for a two-dimensional blind source compressed signal. The blind source is reflected in that the number of effective signal sources is unknown, the azimuth angle is unknown, and the signal complex amplitude is also unknown. Signal data is obtained by a sensor and then compressed and added with noise to obtain detection data. According to the detection data, an approximate message passing method on a factor graph is used to respectively estimate the activated factor sequence and the approximate posterior probability of the signal complex amplitude, the signal angle value is obtained by using a positioning module, and then the estimation value of the signal source number and the signal complex amplitude is obtained according to the signal source number and the approximate posterior probability of the signal complex amplitude. Compared with the prior art, the advantages of the present application are as follows: first, compared with BIG-AMP, the algorithm has the advantage of not needing the prior distribution of the signal azimuth angle; second, compared with ESPRIT, the algorithm has the advantage of also providing an estimation of the signal complex amplitude; and third, compared with the AMP+ESPRIT algorithm, the algorithm has the advantage of allowing the signal source number to be unknown.

The application relates to a UAV array dynamic angle of arrival estimation method and system, which comprises the following steps: S1, acquiring array snapshot data after reference channel auxiliary synchronization and waveform compensation; S2, establishing a parameterized space-time coupling phase model in a short coherence processing interval; S3, based on the array snapshot data, obtaining a single-channel input sequence through beam forming, and estimating a radial parameter pair by using time domain atom matching filtering; S4, based on the radial parameter pair, performing common time phase compensation on the array snapshot data to obtain a compensated snapshot matrix; S5, performing two-dimensional correlation calculation by using a space-time steering atom to estimate an angle parameter pair; S6, constructing a complete space-time dictionary atom, and estimating a complex amplitude by using a least square criterion; and S7, performing successive interference cancellation to update a residual error. Compared with the prior art, the application has the advantages of keeping low signal-to-noise ratio coherence gain and significantly reducing calculation complexity.

The invention discloses an information encryption method and system based on incoherent topological structure light. The method comprises the following steps: determining a target topological structure serving as an encryption key and a statistical coherence parameter representing to-be-encrypted information; constructing a cross spectral density function of a light source surface based on the two, and coding coherent singular point distribution of a corresponding target topological structure in the complex coherence degree; generating a complex amplitude hologram according to the function, generating a partially coherent topological structure light field through modulation of a spatial light modulator, and performing interference with reference light to obtain a light field image; performing coordinate transformation and frequency domain filtering on the image, and extracting a complex coherence degree function and counting far-field intensity distribution corresponding to coherence parameters; and finally, authentication is completed by verifying the consistency of the reconstructed topological structure and the target topological structure, and transmitted information is decoded based on intensity distribution. According to the invention, high-capacity and high-security optical information encryption is realized through two-degree-of-freedom independent coding of a topological structure and statistical coherence.

The invention discloses a mode selection analysis method and system for a satellite-ground laser communication mode diversity technology, a product and an element manufacturing method, belongs to the technical field of space laser communication, and solves the problem that the prior art directly selects first several modes as a group of fixed orthogonal mode bases due to experience; therefore, the technical problem that the stability of a communication link is reduced due to the fact that the optimal performance cannot be kept in a dynamically changing channel is solved. The method comprises the steps of 1, constructing a dynamic turbulence data set; 2, performing dynamic mode decomposition on complex amplitude distribution of the degraded light spots in the dynamic turbulence data set to obtain instantaneous power proportions of the degraded light spots in different modes; and 3, carrying out statistical analysis on the instantaneous power proportions of the degraded light spots in different modes, and screening out an optimal fixed mode combination in combination with the target turbulence intensity. The invention is used for realizing efficient optical signal transmission.

In a digital holographic wrapped phase aberration compensation method based on deep learning, a random Zernike polynomial coefficient and a corresponding wrapped phase map are generated by a computer and are respectively treated as a learning label and a network to train a neural network model. A digital holographic optical setup is built to record a hologram of a sample to be measured, the wrapped phase map is inputted into the trained neural network model after numerical reconstruction, and the Zernike polynomial coefficient is outputted to reconstruct a phase aberration distribution and to compensate complex amplitude in a spatial domain. Phase filtering and unwrapping are performed on the compensated wrapped phase map, and Zernike polynomial fitting based on background segmentation is performed on the unwrapped phase to compensate for residual aberration.

This invention discloses a method and system for phase measurement of metalenses in a refractive-meta-hybrid system. By constructing a reference complex amplitude distribution corresponding to the modulation characteristics of the refractive optical unit, the phase modulation introduced by the refractive optical unit can be decoupled based on the reference complex amplitude distribution after phase inversion. When the physical parameters of the refractive optical unit are set to be equivalent to free space or air, the reference complex amplitude distribution is the light field distribution directly propagated from the illumination source to the surface of the metalens. To address factors such as light source power fluctuations, exposure differences, and non-ideal illumination beam profiles, the measurement amplitude distribution corresponding to the measurement intensity distribution of the defocus plane is normalized and corrected using an energy ratio coefficient. Furthermore, by fusing the reference amplitude distribution with a hybrid weighting factor and the return amplitude distribution corresponding to the return complex amplitude distribution of the exit surface, the stability of the iterative inversion process can be improved and the inversion bias introduced by amplitude mismatch can be reduced.

This invention provides a wavefront phase recovery method, an atmospheric channel estimation method, and an apparatus for atmospheric laser communication systems. The method includes: acquiring multiple sets of deflection measurement amplitude data corresponding to a target distorted beam; obtaining a first complex amplitude corresponding to each set of deflection measurement amplitude data based on a non-convex initialization prediction algorithm; iteratively operating on each set of first complex amplitudes using a gradient descent-based non-convex optimization algorithm to obtain a reconstructed complex amplitude that meets the target recovery conditions; and determining the wavefront phase information of the target distorted beam based on the reconstructed complex amplitude. This invention can obtain the globally optimal wavefront phase information when using a gradient descent-based non-convex optimization algorithm for wavefront phase recovery, thereby improving the accuracy of phase recovery.

The invention provides an electrically tunable three-channel wavefront modulation method and system based on a polarization dependent metasurface, and the method comprises the steps: obtaining an incident light field, and enabling the incident light field to sequentially pass through a polarizer, a first liquid crystal retarder, the metasurface, a second liquid crystal retarder and an analyzer; obtaining a first Jones matrix shared by the polarizer and the analyzer, a second Jones matrix shared by the first liquid crystal delayer and the second liquid crystal delayer, and a metasurface Jones matrix of the metasurface; performing cascade calculation on the first Jones matrix, the second Jones matrix and the metasurface Jones matrix to generate a cascade calculation result; and performing complex amplitude modulation according to a preset target based on a cascade calculation result, electrically adjusting through the first liquid crystal delayer and the second liquid crystal delayer to generate phase shift, generating metasurface related parameters, and performing metasurface design based on the metasurface related parameters to complete wavefront modulation. According to the invention, the problems of few pre-modulation channels and low switching efficiency in the prior art are solved.

The invention discloses a terahertz metasurface reverse design method based on a cascade neural network, and belongs to the crossing field of terahertz technology and artificial intelligence, the method aims at a specific target frequency, the complex amplitude of a metasurface unit structure is extracted as training input, and metasurface unit structure parameters are taken as output; firstly, a forward prediction network is trained, the weight is frozen, then the forward prediction network is cascaded with a reverse design network, a complex amplitude mean square error is used as unique loss, only reverse propagation is carried out on the reverse network, and therefore one-to-one mapping of parameters and responses of a unit structure is established. According to the method, the terahertz metasurface structure parameters can be efficiently and accurately predicted, and the effectiveness of the terahertz metasurface structure parameters is verified through holographic imaging experiments. Through the cascaded bidirectional network structure, the problem of one-to-many mapping in a deep learning reverse design method is effectively solved, and rapid, accurate and reliable reverse design of the terahertz metasurface is realized.

The invention relates to the technical field of metasurfaces, and discloses a double-layer all-metal Huygens metasurface unit with independently regulated amplitude and phase and an antenna. The double-layer all-metal Huygens metasurface unit with independently regulated amplitude and phase does not need a dielectric substrate; the problem of antenna performance reduction caused by dielectric constant change of the dielectric substrate in extreme environments of high temperature, high power radiation and the like can be avoided, the cost is reduced, the double-layer structure can effectively reduce the profile height, and the transmission loss is reduced. The metal plate is provided with the inner concentric folding sub-ring groove and the outer concentric sub-ring groove which are of a specific structure, on the basis that 360-degree transmission phase regulation and control are achieved and the transmission amplitude is kept higher than-2 dB, independent regulation and control of the phase and the amplitude can be achieved, the defect that an existing double-layer all-metal transmission-type metasurface can only control the phase is overcome, and the performance of the metasurface is improved. And complex wavefront control requirements of sidelobe suppression, high-precision beam forming, complex amplitude vector holography and the like can be met.

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 application discloses a metasurface holographic optimization method based on a limited super atom response library selection, belongs to the metasurface holographic field, and has the steps that a three-dimensional logarithmic probability matrix P (an element represents the logarithmic probability of a structure in a response library selected by a super atom at a grid position) is randomly initialized; a Gumbel-Softmax sampling strategy is used to generate a discrete selection matrix, an index corresponding complex amplitude response is constructed, and a complex amplitude distribution matrix of the whole metasurface is constructed; then, a differentiable wave front propagation algorithm is used to calculate a target complex amplitude distribution; multi-polarization multiplexing is supported, image superposition is realized through time multiplexing; a structural similarity constraint is introduced; a total loss value gradient relative to the probability matrix is calculated; the probability matrix is updated through a stochastic gradient descent; and finally, iteration is performed until convergence, so that a selection matrix and a directly manufacturable metasurface structure layout are obtained. The application can realize high-precision and high-efficiency polarization multiplexing metasurface holographic design.

The invention provides a low-noise metasurface holographic 3D display method based on double spatial constraints, and the method comprises the following four steps: 1, carrying out the layering processing of a 3D object, obtaining a target plane light field, calculating the corresponding complex amplitude distribution based on the angular spectrum diffraction principle, and obtaining a target plane light field; by adding double constraints of a step function and bandwidth limitation to the spatial frequency, precise calculation of holographic plane complex amplitude is realized; 2, performing back propagation on the obtained holographic plane complex amplitude and the randomly generated pure phase hologram to obtain a target complex amplitude and a calculation complex amplitude respectively; step 3, generating a loss function by comparing the difference between the amplitude and the phase in the calculated complex amplitude and the target complex amplitude, and continuously iteratively optimizing the loss function through a stochastic gradient algorithm to enable the calculated complex amplitude to approach the target complex amplitude to obtain an optimized pure phase hologram; and 4, designing a metasurface structure according to the optimized pure phase hologram, and when laser irradiates the metasurface structure, reproducing a low-noise reconstructed image of the 3D object.

A system (20) for quantum computing includes an array of qubits (40) and a radiation source (28) that simultaneously applies radiation to a plurality of qubits in the array that includes a set of spectral components having different respective complex amplitudes in a plurality of vibration sidebands of internal transition frequencies of the qubits. The sidebands are generated by a set of normal patterns having a minimum spacing f between respective vibration frequencies. A controller (32) initializes a multi-qubit gate comprising at least five qubits to an initial state and drives the radiation source to apply radiation to each of the qubits at a respective complex amplitude of a spectral component in the selected set so as to switch the multi-qubit gate to a target state for a gate time of less than 50 / f.

The invention discloses a design method of a variable pattern acoustical holography mask, which comprises the following steps: generating a random phase matrix, constructing an object plane initial complex amplitude field based on sound pressure distribution of the lower surface of an acoustical holography mask sheet and the random phase matrix, normalizing a gray value of a target image into a matrix, and taking the matrix as a target sound pressure distribution constraint condition, target phase distribution is solved based on a gradient acceleration iteration angular spectrum method; repeating the steps under different pressurization conditions to obtain target phase distribution under different pressure conditions, and determining optimal thickness distribution of the acoustical holography mask meeting different pressurization conditions simultaneously by using a direct search method; and generating an acoustic holographic mask sheet entity structure according to the thickness distribution. The invention further discloses a system corresponding to the design method. According to the design method and system provided by the invention, the single acoustical holographic mask can generate different target sound field patterns under different pressures by utilizing a phase regulation and control mechanism of an acoustic velocity variable material, so that single-mask multi-image loading is realized.

The present application relates to the technical field of nanophotonics and computational optical imaging, and particularly relates to a computational spectral metasurface reverse design method based on an iterative optimization algorithm, comprising: S1, physical structure parameterization, defining the geometric parameters, arrangement period and material refractive index of the nanostructure in the unit, initializing the physical structure parameters and the corresponding electromagnetic response operator; S2, constructing a differentiable simulation model, using a rigorous coupled wave analysis algorithm based on an automatic differentiation framework to calculate the complex amplitude transmission spectrum data under the current parameters, and keeping the electromagnetic response gradient flow continuous in the calculation graph. In the present application, through end-to-end soft and hard collaborative optimization of the metasurface physical structure parameters and the neural network reconstruction algorithm weight, the deep coupling and collaborative evolution of the hardware coding characteristics and the software decoding logic are realized, the performance mismatch problem caused by the traditional step-by-step design is fundamentally solved, and the restoration accuracy and recognition sensitivity of the system to complex spectral characteristics are significantly improved.

The invention discloses a laser phase noise elimination method and system for a phi-OTDR (Optical Time Domain Reflectometer), solves the problem of dependence of a phase-sensitive optical time domain reflectometer on a high-cost narrow-linewidth laser in the prior art, and realizes reduction of the influence of the phase noise of the laser in combination with a signal processing algorithm. Therefore, the requirement of the system on the line width of the laser is relaxed, the system cost is greatly reduced, and the compatibility of a sensing system and a communication system is improved; the method comprises the following steps: injecting a composite detection pulse into a to-be-detected optical fiber to obtain backscattered light; performing coherent beat frequency on the backscattered light and the local oscillation light to obtain a synthesized complex amplitude electric signal; processing and synthesizing the complex amplitude electric signal, and separating a scattering signal component corresponding to each sub-pulse through a frequency domain filtering or decoding mode; calculating an instantaneous phase difference between the at least one pair of scattered signal components to obtain a spatial differential phase; wherein the space differential phase eliminates common phase noise introduced by the local oscillation light.

A technique for accurately measuring acoustic characteristics of a parametric array is provided. A first calculation unit that calculates a complex amplitude d of an optical phase at a frequency fd from an amount of change φs of the optical phase caused by demodulated sound S, assuming that qdiff(ξ′, η′) is a function defined using a Gaussian beam expansion method, a second calculation unit that calculates a function value qdiff(ξ, η) at a point X and a line integral value ∫Lqdiff(ξ′, η)dξ′ of the function qdiff(ξ′, η) along the optical path L, and a third calculation unit that calculates a complex amplitude p of the demodulated sound with the frequency fd at the point X using the complex amplitude d, the function value qdiff(ξ, η), and the line integral value ∫Lqdiff(ξ′, η)dξ′ are included.

The application discloses a large-interval array ultrasonic signal anti-symmetry Lamb wave dispersion extraction method for a cased well, an electronic device and a program product. The method comprises the following steps: constructing a Hankel matrix according to a frequency domain space sequence of a large-interval ultrasonic Lamb wave array signal, and then solving spatial poles; constructing a Vandermonde matrix according to the spatial poles, and then solving real complex amplitudes of the spatial poles; performing adaptive dynamic phase unwrapping on the spatial poles according to a phase velocity of a prior A0 mode, and obtaining phase velocities and spatial attenuation coefficients of all spatial poles in a full frequency band; selecting an initial anchor point according to the real complex amplitudes of the poles in a dynamic pole library; eliminating cross modes and noise interference according to the initial anchor point and a monotonicity constraint of the phase velocity; eliminating artifact points according to a difference between an error mean of imaginary parts of the dynamic poles and a fitting curve and a fitting variance, and obtaining a final A0 mode dispersion curve. The application effectively suppresses spatial aliasing and mode cross artifact.

The invention discloses a device for calculating logarithm of complex amplitude, a signal processing method, a device, an integrated circuit, an electromagnetic wave device and electronic equipment, which are applied to the field of digital signal processing and are used for calculating and outputting by taking the sum of absolute values of a real part and an imaginary part of a complex as input based on a lookup table. Taking the data as an input, and calculating and outputting the data based on the lookup table; ,...; the embodiment of the invention does not need a multiplier, and the hardware area is small. Compared with the prior art, the method has the advantage of higher cost, and can also achieve higher numerical precision when the lookup table is used for calculating the logarithm.