5 results about "Helmholtz equation" patented technology

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.

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 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.