9 results about "Helmholtz equation" patented technology

The invention discloses a PINN-based large numerical aperture photoetching objective lens vector diffraction field calculation method, which comprises the following steps: obtaining a three-dimensional vector diffraction light field of a large NA photoetching objective lens through simulation, reconstructing the three-dimensional vector diffraction light field at a sampling point position, and generating corresponding complex electric field distribution matrix data; performing physical purification on the complex electric field distribution matrix data to construct a corresponding data set; constructing a corresponding Helmholtz equation as a constraint equation based on the light field tight focusing characteristic of the large NA photoetching objective lens; constructing an initial model, and training the initial model by using the data set in combination with the constraint equation to obtain a PINN model for predicting complex electric field data; and inputting space coordinates of a to-be-predicted target into the PINN model to obtain complex electric field data. According to the method provided by the invention, the calculation efficiency of the vector diffraction field can be remarkably improved on the premise of keeping relatively high simulation precision, and the method is suitable for rapid modeling and analysis of the three-dimensional vector light field of the large-numerical-aperture photoetching object mirror.

The invention discloses an atmospheric laser communication turbulence compensation method based on a novel Kolmogorov-Zakharov model, and belongs to the technical field of atmospheric laser communication. The objective of the invention is to solve the technical problem that the transmission quality and stability of atmosphere laser communication are affected due to reduction of compensation precision in a strong turbulence scene in the prior art. The method comprises the following steps: acquiring phase distribution and light intensity fluctuation of a laser signal in real time to obtain an atmospheric refractive index structure constant, mapping a model parameter and an atmospheric laser communication physical quantity, and updating a model based on the atmospheric refractive index structure constant; based on the model and a Helmholtz equation of atmospheric laser transmission, an atmospheric laser channel KZ turbulence random matrix model is obtained and solved, and a prediction result is obtained; and then turbulence dynamic compensation is carried out based on a prediction result. The method is mainly used for atmosphere laser communication turbulence compensation.

This invention relates to a method for preparing vector Hermitian-Laguerre Gaussian beams based on collinear interference. Combining the relationship between the Poincaré sphere and the Jones matrix, and based on the vortex light field generated by the complete solutions of two sets of Helmholtz equations, a method for preparing vector Hermitian-Laguerre Gaussian beams based on collinear interference is proposed. Unlike the commonly used single-mode vector light field preparation, this method, based on a phase-type spatial light modulator, a polarization beam splitter, and a half-wave plate, realizes the preparation of a dual-mode vector Hermitian-Laguerre Gaussian beam, reconstructs the polarization distribution on its intensity cross section, and studies the influence of mode difference on the polarization distribution with transmission distance. Compared with traditional single-mode vector light fields, this method achieves good results in preparing vector light fields with different modes. This method belongs to the category of light field manipulation and can be applied to the design of optical polarization elements.

The embodiment of the invention discloses a Helmholtz equation quantum solving method and an electromagnetic wave characteristic determination method and device, and the method comprises the steps: carrying out the series expansion of a solution and a source item of a Helmholtz equation according to a selected primary function, and discretizing a computational domain of the Helmholtz equation into grid points; substituting the solution and the series form of the source item into a margin function corresponding to the Helmholtz equation, and applying a weighted margin method at each network point to obtain a large linear equation set of which the dimension is consistent with the number of grid points; solving a linear equation set through a quantum linear solver to obtain a solution coefficient of the primary function, wherein the linear equation set is obtained by applying a weighted margin method to all grid points; and substituting the solution coefficient of the primary function into the series form of the solution to obtain the solution. By adopting the embodiment of the invention, the hardware resources of the computer can be saved, and the solving speed of the Helmholtz equation can be improved.

This invention relates to the field of geophysical exploration technology, specifically to a high-precision three-dimensional forward modeling method for airborne electromagnetic spectral elements considering induced polarization effects. Based on the Cole-Cole model, a complex conductivity expression considering induced polarization effects is established, and the frequency domain Helmholtz equation is introduced to construct the corresponding governing equations. A regular hexahedral mesh is generated, and reference domain vector basis functions are constructed using the Gauss-Lobatto-Legendre orthogonal polynomial method according to the spectral element method. The mapping relationship between these functions and physical mesh elements is established. The Galerkin weighted residual method is applied to discretize the governing equations into element system matrices, which are then assembled to form the overall system matrix and the corresponding linear equation set. A direct solver is used to obtain the frequency domain three-dimensional electromagnetic response, and the time domain three-dimensional forward modeling result of the computational region is obtained through Hankel transformation. This invention achieves rapid and high-precision three-dimensional forward modeling simulation of complex geological models containing induced polarization effects.

The application discloses a terahertz environment semantic map construction method based on a physical information flow matching model, and relates to the technical field of communication.The method comprises the following steps: constructing a sparse directional beam received signal strength dataset of a real scene collection, a real omnidirectional radio map and a training set of a real physical environment; constructing a flow matching model with a built-in three-class propagation region dynamic judgment module, taking the sparse data as a condition, integrating a Helmholtz equation constraint and a regionalized power boundary constraint as double physical constraints, synchronously generating a radio map and a physical environment by adopting a double-output U-Net architecture, and training through a non-classifier guiding mechanism; in actual application, sparse directional beam data is collected to input the trained model, and an omnidirectional radio map and a physical environment of a current scene are generated by reasoning.The application solves the problems of sparse data and poor physical consistency in terahertz communication, reduces the hardware and time cost, and improves the map construction precision and generalization ability.

The method for modeling complex scattering channel in airplane cabin under electromagnetic constraint and freedom degree analysis belongs to the cross technical field of wireless communication channel modeling and electromagnetic information theory, and aims to solve the problem that the current airplane cabin internal communication system lacks channel model for algorithm design. The method is based on Green function and distribution of electromagnetic excitation source in space to determine the electric field distribution of any point; the spherical wave is equivalent to the superposition of plane waves radiated in each direction, the Green function is expressed as the combination form of plane waves according to the decomposition of spherical wave, and then the electric field expression when the excitation source is an impulse current source is obtained; based on the eigen solution of homogeneous Helmholtz equation, the response value corresponding to the wave number direction is divided into two hemispheres according to space, and then the receiving channel coefficient expressed by the combination of eigen functions is obtained, the channel model is connected with the electromagnetic wave space distribution according to the receiving channel coefficient, and the channel model meeting the electromagnetic distribution constraint is obtained.

The invention discloses a ring array ultrasonic imaging method and system based on frequency domain transformation, and provides an imaging algorithm system based on Helmholtz equation frequency domain modeling and a bispectrum reconstruction mechanism in order to solve the problems of high wave field curvature, serious near-field interference, insufficient real-time performance and the like in a small-radius outward imaging ring array structure. The method comprises the steps of signal acquisition, frequency domain transformation, angular Fourier expansion, radial Hankel transformation reconstruction and minimum group delay wavefront fitting correction. According to the system, a propagation model is established in a cylindrical spectrum domain, decoupling of radial and angular components and fast FFT operation are achieved, and the complexity of a delay summation algorithm is reduced; meanwhile, near-field phase distortion and a sidelobe diffusion effect are suppressed through a wavefront correction strategy constrained by minimum group delay. The method is suitable for external ring array scenes such as intravascular cavity, prostate and industrial detection, and real-time imaging can be realized on GPU, DSP and FPGA platforms.

The application discloses a large numerical aperture lithography objective vector diffraction field calculation method based on PINN, comprising the following steps: obtaining a three-dimensional vector diffraction light field of a large NA lithography objective through simulation, reconstructing the three-dimensional vector diffraction light field at a sampling point position, and generating corresponding complex electric field distribution matrix data; performing physical purification on the complex electric field distribution matrix data to construct a corresponding data set; constructing a corresponding Helmholtz equation as a constraint equation based on the light field tight focusing characteristics of the large NA lithography objective; constructing an initial model, training the initial model by using the data set in combination with the constraint equation, and obtaining a PINN model for predicting complex electric field data; and inputting the spatial coordinates of a target to be predicted into the PINN model to obtain complex electric field data. The method provided by the application can significantly improve the calculation efficiency of the vector diffraction field while maintaining high simulation accuracy, and is suitable for fast modeling and analysis of three-dimensional vector light fields of large numerical aperture lithography objectives.