A method and system for controlling a polarized wave of a transition radiation based on an isotropic material

Abstract

The application discloses a kind of based on isotropic material's transition radiation polarized wave regulation method and system, regulation method includes: according to the velocity vector of oblique incidence electron pulse calculation equivalent current and current is converted to frequency and wave number space;According to the set of Maxwell equations, electron radiation field equation and interface radiation field equation are calculated;Solving electron radiation field equation and interface radiation field equation obtains electron radiation field and interface radiation field;Total field on the two sides of the interface of regulation material is calculated using phase matching algorithm;When using boundary phase matching, the far-field radiation angular spectrum of transverse magnetic wave excited by electron incidence and the far-field radiation angular spectrum of transverse electric wave are calculated;According to the relationship between the calculated transition radiation field energy angular spectrum spatial distribution and electron pulse incidence angle and / or regulation material electromagnetic parameter, transition radiation polarized wave is separated in space.This application solves the problem that existing scheme is difficult to independently regulate the excitation of different mode transition radiation wave and the separation of different mode radiation field in space.

Description

Technical Field

[0001] This invention belongs to the field of communication technology, and in particular relates to a method and system for controlling transit radiation polarization waves based on isotropic materials. Background Technology

[0002] When a particle passes through a medium interface, the transient electronic field couples with the interface, exciting a new radiation phenomenon called transit radiation. A significant characteristic that distinguishes transit radiation from other free electron radiation, such as Cherenkov radiation, is that its radiated energy is proportional to the Lorentz constant over the relativistic velocity range, enabling the excitation of a very wide spectrum from microwaves to X-rays, and the generation of radiation is not limited by particle velocity. These characteristics simultaneously demonstrate the broad application prospects of transit radiation in various fields such as high-energy physics, astronomy, biomedicine, and quantum information processing.

[0003] To control transit radiation on demand, total field radiation manipulation methods based on photonic crystals, gain materials, ENZ materials, and recently metasurfaces have been proposed. For example, PTFE photonic crystals can achieve 5° directional radiation in the millimeter-wave band; gain materials and ENZ materials can achieve radiation enhancements of 4 and 8 orders of magnitude, respectively; and metasurfaces can control the direction and intensity of transit radiation from higher-velocity particles. However, current transit radiation manipulation schemes mainly focus on controlling the field intensity, directionality, and frequency, lacking control over the polarization properties of transit radiation, i.e., the excitation of different modes of transit radiation waves and the spatial separation of different mode radiation fields. Polarization is a fundamental characteristic of the radiation field and is closely related to practical applications, such as particle detectors, sensors, S-beam splitters, spatial filters, and polarization and angle-selective systems. This results in low manipulation efficiency of current transit radiation manipulation schemes, hindering their wider application.

[0004] To address the challenges of autonomously controlling the excitation of different modes of transit radiation waves and spatially separating radiation fields of different modes, a method and system for controlling transit radiation polarization waves based on isotropic materials is proposed. Summary of the Invention

[0005] This invention proposes a method and system for controlling the polarization of transit radiation based on isotropic materials, which at least solves the problem that existing schemes cannot autonomously control the excitation of different modes of transit radiation waves and the spatial separation of different modes of radiation fields.

[0006] According to an embodiment of the present invention, a method for controlling transit radiation polarization waves based on isotropic materials is provided, comprising:

[0007] The equivalent current is calculated based on the velocity vector of the obliquely incident electron pulse, and the current is converted to the frequency and wavenumber space.

[0008] Calculate the electron radiation field equation and the interface radiation field equation based on Maxwell's equations;

[0009] Solving the electron radiation field equation and the interface radiation field equation yields the electron radiation field and the interface radiation field under the transverse magnetic wave polarization mode and the transverse electric wave polarization mode.

[0010] The phase-matching algorithm is used to calculate and control the total field on both sides of the material interface;

[0011] Boundary phase matching was used to calculate the far-field radiation angular spectrum of transverse magnetic waves and transverse electric waves excited when electrons were incident, i.e. the spatial distribution of the energy angular spectrum of the transit radiation fields on both sides.

[0012] The spatial separation of the transit radiation polarization wave is controlled by adjusting the spatial distribution of the calculated transit radiation field energy angular spectrum with the incident angle of the electron pulse and / or the electromagnetic parameters of the control material.

[0013] In one exemplary embodiment, the step of calculating the equivalent current based on the obliquely incident electron pulse velocity vector and converting the current to frequency and wavenumber space includes:

[0014] Calculate the velocity vector of the obliquely incident electron pulse based on the incident angle of the electron pulse;

[0015] Calculate the equivalent current based on the components of the velocity vector in the spatial coordinate system;

[0016] The current is converted to frequency and wavenumber space to obtain the radiation characteristics at a specific frequency point.

[0017] In one exemplary embodiment, the calculation of the electron radiation field equation and the interface radiation field equation based on Maxwell's equations includes:

[0018] Substitute the transformed current equation into Maxwell's equations;

[0019] Calculate the electron radiation field equation and the interface radiation field equation based on Maxwell's equations.

[0020] In an exemplary embodiment, solving the electron radiation field equation and the interface radiation field equation to obtain the electron radiation field and interface radiation field in the transverse magnetic wave polarization mode and the transverse electric wave polarization mode includes:

[0021] Calculate the electric field radiation coefficient based on the boundary conditions;

[0022] The electron radiation field is calculated based on the electron radiation field equation and the electric field radiation coefficient, including the electron radiation electric field in the transverse magnetic wave polarization mode and the electron radiation magnetic field in the transverse electric wave polarization mode.

[0023] The interface radiation field is calculated based on the interface radiation field equation and the electric field radiation coefficient, including the interface radiation electric field in the transverse magnetic wave polarization mode and the interface radiation magnetic field in the transverse electric wave polarization mode.

[0024] In an exemplary embodiment, the step of calculating the total field on both sides of the material interface using a phase-matching algorithm includes:

[0025] Phase-matching calculations were used to control the space radiation electric and magnetic fields on one side of the material interface.

[0026] The total field on both sides of the material interface is formed by the sum of the electric and magnetic fields excited at the interface and the electric and magnetic fields generated by the direct radiation of electron pulses.

[0027] In an exemplary embodiment, the step of calculating the far-field radiation angular spectrum of the transverse magnetic wave and the far-field radiation angular spectrum of the transverse electric wave excited upon electron incident using boundary phase matching includes:

[0028] The radiation coefficient of the electromagnetic field is calculated based on boundary phase matching;

[0029] The expression for the far-field radiation angular spectrum of transverse magnetic waves is calculated using Poynting's theorem.

[0030] The expression for the far-field radiation angular spectrum of transverse electric waves is calculated using Poynting's theorem.

[0031] Substituting the radiation coefficient of the electromagnetic field into the expressions for the far-field radiation angle spectrum of transverse magnetic waves and transverse electric waves, the far-field radiation angle spectra of transverse magnetic waves and transverse electric waves excited by electron incident are calculated.

[0032] In an exemplary embodiment, the step of controlling the spatial separation of the transit radiation polarization wave based on the calculated spatial distribution of the transit radiation field energy angular spectrum and the electron pulse incident angle and / or the relationship between the electromagnetic parameters of the control material includes:

[0033] The influence equation of electron pulse incident angle is calculated based on the effect of electron pulse incident angle variation on transverse magnetic wave far-field radiation angle spectrum and transverse electric wave far-field radiation angle spectrum.

[0034] The influence equation of the electromagnetic parameters of the control material is calculated based on the effect of the change of the electromagnetic parameters of the control material on the far-field radiation angle spectrum of transverse magnetic wave and transverse electric wave.

[0035] Calculate the influence equation of radiation polarization wave based on the influence equation of electron pulse incident angle and / or the influence equation of material electromagnetic parameters;

[0036] The spatial distribution of the required polarization wave and the electron pulse incident angle corresponding to the radiation direction are calculated based on the radiation polarization wave influence equation, the transverse magnetic wave far-field radiation angle spectrum and the transverse electric wave far-field radiation angle spectrum, and / or the electromagnetic parameters of the material are controlled.

[0037] By configuring the calculated incident angle of the electron pulse and / or adjusting the electromagnetic parameters of the material, the desired radiation polarization wave is obtained, thus realizing the control of the transit radiation polarization wave.

[0038] According to another embodiment of the present invention, a transit radiation polarization wave manipulation system based on isotropic materials is also provided, comprising:

[0039] The radiation control unit is used to calculate the electron pulse incident angle and / or control the electromagnetic parameters of the material based on the spatial distribution and radiation direction control requirements of the polarization wave and the transit radiation polarization wave control method based on isotropic materials.

[0040] Electromagnetic radiation generating unit: used to emit electron pulses according to the electron pulse incident angle calculated by the radiation control unit. The electron pulses strike the control material at a uniform speed with an incident angle and a preset velocity, generating electromagnetic radiation and exciting transverse electric waves and transverse magnetic waves.

[0041] In an exemplary embodiment, the transverse electric wave is an electromagnetic wave with only an electric field component in the direction perpendicular to the electron pulse incident surface, and the transverse magnetic wave is an electromagnetic wave with only a magnetic field component in the direction perpendicular to the electron pulse incident surface.

[0042] In one exemplary embodiment, the control material is an isotropic material, preferably any one of polytetrafluoroethylene, polyethylene, and epoxy resin.

[0043] The advantages of the method and system for controlling transit radiation polarization waves based on isotropic materials according to the present invention are as follows:

[0044] (1) Using isotropic materials as radiation control materials, compared with control devices using anisotropic materials such as metasurfaces, the structure is simpler and easier to manufacture, which can significantly reduce the device size and is conducive to the subsequent miniaturization and intelligent application of the device.

[0045] (2) The radiation energy angular spectrum can be controlled on demand based on the combination characteristics of the incident angle of the incident electron pulse and the electromagnetic parameters of the control material. Compared with the traditional transit radiation control unit, it can effectively realize the excitation of radiation fields of different modes along different directions, thereby realizing the automatic spatial separation of radiation modes and eliminating the subsequent complex mode extraction steps.

[0046] (3) Based on the influence of the change in the incident angle of the electron pulse and / or the change in the electromagnetic parameters of the control material on the far-field radiation angle spectrum of the transverse magnetic wave and the far-field radiation angle spectrum of the transverse electric wave, the spatial distribution of the required polarization wave and the change in the incident angle of the electron pulse and / or the change in the electromagnetic parameters of the control material corresponding to the radiation direction are calculated. Compared with the traditional transit radiation control unit, the polarization characteristics of transit radiation can be adjusted more accurately and effectively, which is convenient for realizing the concentrated excitation of the energy angle spectrum in space or the multi-mode controllable excitation. The control efficiency is higher and it is suitable for more transit radiation application scenarios. Attached Figure Description

[0047] Figure 1 This is a flowchart of a method for controlling transit radiation polarization waves based on isotropic materials according to an embodiment of the present invention;

[0048] Figure 2 This is a flowchart of the method for sub-step S01 in an embodiment of the present invention;

[0049] Figure 3 This is a flowchart of the method for sub-step S02 in an embodiment of the present invention;

[0050] Figure 4 This is a flowchart of the method for sub-step S03 in an embodiment of the present invention;

[0051] Figure 5 This is a flowchart of the method for sub-step S04 in an embodiment of the present invention;

[0052] Figure 6 This is a flowchart of sub-step S05 of an embodiment of the present invention;

[0053] Figure 7 This is a flowchart of sub-step S06 of an embodiment of the present invention;

[0054] Figure 8 This is a schematic diagram of spatial separation of transit radiation radio wave modes according to an embodiment of the present invention, wherein, Figure 8 (a) is the transverse magnetic wave mode excited at an incident angle of 20°. Figure 8 (b) is the transverse electromagnetic wave mode excited at an incident angle of 20°. Figure 8 (c) is the transverse magnetic wave mode excited at an incident angle of 80°. Figure 8 (d) is the transverse electromagnetic wave mode excited at an incident angle of 80°;

[0055] Figure 9 This is a schematic diagram of a transit radiation polarization wave modulation system based on isotropic materials according to an embodiment of the present invention. Detailed Implementation

[0056] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention. The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. No specific limitations are made in this application depending on the specific settings of the actual application environment.

[0057] The space is defined by a Cartesian coordinate axis along the plane containing the control material, where the xy-axis is the plane containing the control material surface, and the z-axis is perpendicular to the control material surface. The vertical axis of the polar coordinate system is defined as the x-axis of the Cartesian coordinate system. The angle φ in the polar coordinate system represents the angle with the x-axis, ranging from 0 to 360°. The radial distance in the polar coordinate system represents the pitch angle in free space, ranging from 0 to 90°; the incident angle of charged particles ranges from 0 to 90°, but not including 90°. In this embodiment of the invention, an electron pulse is obliquely incident on the control material. The combination of the electromagnetic parameters of the control material (including the dielectric constant ε and magnetic permeability μ) and the incident angle of the electron pulse is used to achieve on-demand control of the radiation energy angular spectrum, including the excitation of transverse electric and magnetic waves, and the automatic separation of the radiation direction.

[0058] According to an embodiment of the present invention, a method for controlling transit radiation polarization waves based on isotropic materials is provided, the flowchart of which is shown below. Figure 1 As shown, it includes:

[0059] Step S01: Calculate the equivalent current based on the velocity vector of the obliquely incident electron pulse and convert the current to the frequency and wavenumber space;

[0060] Step S02: Calculate the electron radiation field equation and the interface radiation field equation based on Maxwell's equations;

[0061] Step S03: Solve the electron radiation field equation and the interface radiation field equation to obtain the electron radiation field and interface radiation field in the transverse magnetic wave polarization mode and the transverse electric wave polarization mode.

[0062] Step S04: Calculate the total field on both sides of the control material interface using a phase-matching algorithm;

[0063] Step S05: Calculate the far-field radiation angular spectrum of the transverse magnetic wave and the far-field radiation angular spectrum of the transverse electric wave excited when the electron is incident, i.e. the spatial distribution of the energy angular spectrum of the radiation fields on both sides.

[0064] Step S06: Based on the calculated spatial distribution of the energy angular spectrum of the transit radiation field and the relationship between the incident angle of the electron pulse and / or the electromagnetic parameters of the control material, the spatial separation of the transit radiation polarization wave is controlled.

[0065] In an exemplary embodiment, step S01, calculating the equivalent current based on the obliquely incident electron pulse velocity vector and converting the current to frequency and wavenumber space, is illustrated in the flowchart below. Figure 2 As shown, it includes:

[0066] Step S011: Calculate the velocity vector of the obliquely incident electron pulse based on the incident angle of the electron pulse;

[0067] Step S012: Calculate the equivalent current based on the components of the velocity vector in the spatial coordinate system;

[0068] Step S013: Convert the current to frequency and wavenumber space to obtain the radiation characteristics at a specific frequency point.

[0069] In this embodiment, the incident angle θ is determined by the angle θ0 between the electron pulse incident direction and the normal to the material surface, where the normal points from the material to the vacuum. Therefore, the incident angle θ is equal to π - θ0. Based on the incident angle θ and the conversion relationship between polarized coordinates and rectangular coordinates, the velocity vector of the obliquely incident electron pulse is obtained, expressed as: The equivalent current is calculated based on this. To obtain the radiation characteristics at a specific frequency, the current needs to be converted to frequency and wavenumber space. After the transformation, the equivalent current in frequency and wavenumber space is obtained as follows: ,in, Let ω be the horizontal wave vector, ω be the frequency, and q be the number of electrons in the particle.

[0070] In an exemplary embodiment, step S02, calculating the electron radiation field equation and the interface radiation field equation based on Maxwell's equations, is illustrated in the flowchart below. Figure 3 As shown, it includes:

[0071] Step S021: Substitute the transformed current equation into Maxwell's equations;

[0072] Step S022: Calculate the electron radiation field equation and the interface radiation field equation based on Maxwell's equations.

[0073] In this embodiment, the equivalent current in frequency and wavenumber space is substituted into Maxwell's equations, which are:

[0074] (1)

[0075] (2)

[0076] (3)

[0077] The electron radiation field equation and the interface radiation field equation are derived from Maxwell's equations. The electron radiation field equation in the transverse magnetic wave polarization mode is shown in equation (4), and the interface radiation field equation is shown in equation (5).

[0078] (4)

[0079] (5)

[0080] In an exemplary embodiment, step S03, solving the electron radiation field equation and the interface radiation field equation to obtain the electron radiation field and interface radiation field in the transverse magnetic wave polarization mode and the transverse electric wave polarization mode, is illustrated in the flowchart below. Figure 4 As shown, it includes:

[0081] Step S031: Calculate the electric field radiation coefficient based on the boundary conditions;

[0082] Step S032: Calculate the electron radiation field based on the electron radiation field equation and the electric field radiation coefficient, including the electron radiation electric field in the transverse magnetic wave polarization mode and the electron radiation magnetic field in the transverse electric wave polarization mode.

[0083] Step S033: Calculate the interface radiation field based on the interface radiation field equation and the electric field radiation coefficient, including the interface radiation electric field in the transverse magnetic wave polarization mode and the interface radiation magnetic field in the transverse electric wave polarization mode.

[0084] In this embodiment, the electric field radiation coefficient a1 is calculated based on the boundary conditions; the z component of the electron radiation electric field in the transverse magnetic wave polarization mode is calculated based on the electron radiation field equation and the electric field radiation coefficient, as shown in equation (6).

[0085] (6)

[0086] Similarly, the x and y components of the electron radiation electric field in the transverse magnetic wave polarization mode can be calculated, which is the electron radiation electric field in the transverse magnetic wave polarization mode.

[0087] Using the same method, the z-component of the electron radiation magnetic field in the transverse electric wave polarization mode can also be calculated, as shown in equation (7).

[0088] (7)

[0089] Similarly, the x and y components of the electron radiation magnetic field in the transverse electric wave polarization mode can be calculated, which is the electron radiation magnetic field in the transverse electric wave polarization mode.

[0090] The z-component of the interface radiation electric field in the transverse magnetic wave polarization mode is calculated based on the interface radiation field equation and the electric field radiation coefficient, as shown in equation (8).

[0091] (8)

[0092] Similarly, the x and y components of the interface radiation electric field in the transverse magnetic wave polarization mode can be calculated, which is the interface radiation electric field in the transverse magnetic wave polarization mode.

[0093] Using the same method, the z-component of the interface radiation magnetic field in the transverse electric wave polarization mode can also be calculated, as shown in equation (9).

[0094] (9)

[0095] Similarly, the x and y components of the interface radiation magnetic field in the transverse electric wave polarization mode can be calculated, which is the interface radiation magnetic field in the transverse electric wave polarization mode.

[0096] In an exemplary embodiment, step S04, which involves calculating the total field on both sides of the material interface using a phase-matching algorithm, is illustrated in the flowchart below. Figure 5 As shown, it includes:

[0097] Step S041: Use phase matching to calculate and control the space radiation electric field and space radiation magnetic field on one side of the material interface;

[0098] Step S042: The total field on both sides of the material interface is formed by the sum of the electric and magnetic fields excited at the interface and the electric and magnetic fields generated by the direct radiation of the electron pulse.

[0099] In this embodiment, taking the xy plane where the material interface is located as a reference, the step of using phase matching to calculate and control the spatial radiation electric field and spatial radiation magnetic field on one side of the material interface is based on phase matching conditions. and To calculate the electric and magnetic fields of space radiation when z>0 or z<0, where , and , The magnetic and electric fields on either side of the interface are, respectively:

[0100] (10)

[0101] (11)

[0102] (12)

[0103] (13)

[0104] The numbers 1 and 2 in the labels represent the parameters corresponding to the upper and lower half-space, the q symbol represents the parameter corresponding to the charge, the R symbol represents the parameter corresponding to the transit radiation field, the z symbol represents the z component of the parameter in the rectangular coordinate system, the angular frequency of the radiated radio wave, and k is the corresponding wave number.

[0105] The total field includes the electric and magnetic fields generated at the interface, as well as the electric and magnetic fields generated by direct electron radiation; these four fields are summed to form the total field on both sides of the interface. In this case... , and , All field components are already included. In actual implementation, the field vectors on both sides of the interface can be superimposed.

[0106] In an exemplary embodiment, step S05, calculating the transverse magnetic wave far-field radiation angular spectrum and transverse electric wave far-field radiation angular spectrum excited at electron incidence using boundary phase matching, is illustrated in the flowchart below. Figure 6 As shown, it includes:

[0107] Step S051: Calculate the radiation coefficient of the electromagnetic field based on the boundary phase matching;

[0108] Step S052: Calculate the far-field radiation angular spectrum expression of transverse magnetic waves using Poynting's theorem;

[0109] Step S053: Calculate the far-field radiation angular spectrum expression of transverse electric waves using Poynting's theorem;

[0110] Step S054: Substitute the radiation coefficient of the electromagnetic field into the expressions for the far-field radiation angle spectrum of the transverse magnetic wave and the far-field radiation angle spectrum of the transverse electric wave to calculate the far-field radiation angle spectrum of the transverse magnetic wave and the far-field radiation angle spectrum of the transverse electric wave excited when the electron is incident.

[0111] In this embodiment, the radiation coefficients a1 and b1 of the electromagnetic field are calculated based on the boundary phase matching, as expressed in equations (14) and (15).

[0112] (14)

[0113] (15)

[0114] The expression for the far-field radiation angular spectrum of transverse magnetic waves is calculated using Poynting's theorem, as shown in equation (16).

[0115] (16)

[0116] The expression for the far-field radiation angular spectrum of transverse electric waves is calculated using Poynting's theorem, as shown in equation (17).

[0117] (17)

[0118] Substituting the radiation coefficient of the electromagnetic field into the expressions for the far-field radiation angular spectrum of transverse magnetic waves and transverse electric waves, the far-field radiation angular spectrum of transverse magnetic waves and transverse electric waves excited by electron incident can be calculated, thus obtaining the spatial distribution of the energy angular spectrum.

[0119] In an exemplary embodiment, step S06, which involves controlling the spatial separation of the transit radiation polarization wave based on the calculated spatial distribution of the transit radiation field energy angular spectrum and the electron pulse incident angle and / or the relationship between the electromagnetic parameters of the control material, is illustrated in the flowchart below. Figure 7 As shown, it includes:

[0120] Step S061: Calculate the equation for the influence of the electron pulse incident angle on the far-field radiation angle spectrum of transverse magnetic waves and the far-field radiation angle spectrum of transverse electric waves based on the effect of the change in the incident angle of the electron pulse.

[0121] Step S062: Calculate the influence equation of the electromagnetic parameters of the control material based on the effect of the change of the electromagnetic parameters of the control material on the far-field radiation angle spectrum of the transverse magnetic wave and the far-field radiation angle spectrum of the transverse electric wave.

[0122] Step S063: Calculate the radiation polarization wave influence equation based on the electron pulse incident angle influence equation and / or the material electromagnetic parameter control influence equation;

[0123] Step S064: Calculate the required spatial distribution of polarization waves and the electron pulse incident angle corresponding to the radiation direction, and / or adjust the electromagnetic parameters of the material, based on the radiation polarization wave influence equation, the transverse magnetic wave far-field radiation angle spectrum, and the transverse electric wave far-field radiation angle spectrum.

[0124] Step S065: Configure the material according to the calculated incident angle of the electron pulse and / or the electromagnetic parameters of the control material to obtain the required radiation polarization wave, that is, realize the control of the transit radiation polarization wave.

[0125] In this embodiment, the equation for calculating the influence of the electron pulse incident angle on the transverse magnetic wave far-field radiation angle spectrum and the transverse electric wave far-field radiation angle spectrum is obtained by training the spatial distribution of the transverse magnetic wave far-field radiation angle spectrum and the transverse electric wave far-field radiation angle spectrum excited under different electron pulse incident angles. The spatial distribution of the radiation angle spectrum is represented by U, and the equation for the relationship between the electron pulse incident angle and the spatial distribution of the radiation angle spectrum is expressed as U=f(θ).

[0126] The equation for calculating the influence of the electromagnetic parameters of the control material on the far-field radiation angle spectrum of transverse magnetic waves and transverse electric waves is obtained by training the spatial distribution of the far-field radiation angle spectrum of transverse magnetic waves and transverse electric waves excited under different permittivity and permeability of different control materials. The equation for the relationship between the electromagnetic parameters of the control material and the spatial distribution of the radiation angle spectrum is expressed as U=g(ε,μ).

[0127] The calculation of the radiation polarization wave influence equation based on the electron pulse incident angle influence equation and / or the material electromagnetic parameter influence equation is obtained by calculating the radiation polarization wave influence equation based on the relationship equation between the electron pulse incident angle and the spatial distribution of the radiation angular spectrum U=f(θ) and / or the relationship equation between the material electromagnetic parameters and the spatial distribution of the radiation angular spectrum U=g(ε,μ), denoted as U=h[f(θ), g(ε,μ)];

[0128] Based on the spatial distribution and radiation direction of the desired polarization wave, the value of the spatial distribution U of the radiation angle spectrum is obtained. The radiation polarization wave influence equation U=h[f(θ), g(ε, μ)] is solved to obtain the corresponding electron pulse incident angle θ and / or the electromagnetic parameters (ε, μ) of the material are controlled.

[0129] The electron pulse incident angle is adjusted or the material is selected based on the calculated incident angle θ of the electron pulse and / or the electromagnetic parameters (ε, μ) of the control material to obtain the desired radiation polarization wave, thus realizing the control of the transit radiation polarization wave.

[0130] Data simulation was performed on the method described in the embodiments of the present invention to obtain the following results: Figure 8 The diagram shown illustrates the spatial separation of transit radiation modes. When an electron pulse incident at an angle of 20° is used, the excited transverse magnetic wave mode is as follows: Figure 8 As shown in (a), the excited transverse electric wave mode is as follows: Figure 8 As shown in (b), it can be clearly seen that the polarization wave excited at an electron pulse incident angle of 20° exhibits opposite-side separation; when the electron pulse incident angle is 80°, the excited transverse magnetic wave mode is as follows: Figure 8 As shown in (c), the excited transverse electric wave mode is as follows: Figure 8 As shown in (d), it is evident that the polarization waves excited at an electron pulse incident angle of 80° exhibit same-side separation. Therefore, by flexibly adjusting the electron incident angle and selecting appropriate materials, spatial separation of transit radiation electromagnetic wave modes can be effectively achieved.

[0131] According to another embodiment of the present invention, a transit radiation polarization wave modulation system based on isotropic materials is also provided, the structural schematic diagram of which is shown below. Figure 9 As shown, it includes:

[0132] The radiation control unit is used to calculate the electron pulse incident angle and / or control the electromagnetic parameters of the material based on the spatial distribution and radiation direction control requirements of the polarization wave and the transit radiation polarization wave control method based on isotropic materials.

[0133] Electromagnetic radiation generating unit: used to emit electron pulses according to the electron pulse incident angle calculated by the radiation control unit. The electron pulses strike the control material at a uniform speed with an incident angle and a preset velocity, generating electromagnetic radiation and exciting transverse electric waves and transverse magnetic waves.

[0134] In an exemplary embodiment, the transverse electric wave is an electromagnetic wave with only an electric field component in the direction perpendicular to the electron pulse incident surface, and the transverse magnetic wave is an electromagnetic wave with only a magnetic field component in the direction perpendicular to the electron pulse incident surface.

[0135] In one exemplary embodiment, the control material is an isotropic material, preferably any one of polytetrafluoroethylene, polyethylene, and epoxy resin; however, it is not limited to this, and any material with a relative permittivity of 2 can be used, and different materials can be selected according to different excitation requirements.

[0136] Furthermore, the system model of the present invention includes two media: the upper layer is a vacuum, and the lower layer is a control material used to generate transit radiation. The interface between the two media is planar.

[0137] Furthermore, automatic separation of radiation direction is defined as transverse electric waves and transverse magnetic waves radiating in different directions in space without interfering with each other; the control object of the radiation field is the far field of radiation, which is determined by the angular spectral density of the transit radiation energy.

[0138] Furthermore, apart from the embodiments described above, the degrees of freedom related to the transit radiation angular spectrum in this application are all ranges of adjustable parameters, including the material's dielectric constant and magnetic permeability, and electron pulse velocity; these will not be listed individually in this application. It should be noted that the terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, or material that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, or material. Without further limitations, the statement only lists typical elements and does not exclude the presence of other identical elements in the process, method, or material that includes said elements.

[0139] Of course, the above descriptions are merely typical examples of specific embodiments of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not limited to the embodiments shown herein, and any changes or modifications to the above embodiments within the scope of this invention will fall within the protection scope of this invention.

Claims

1. A method for controlling transit radiation polarization waves based on isotropic materials, characterized in that, include: The equivalent current is calculated based on the velocity vector of the obliquely incident electron pulse, and the current is converted to the frequency and wavenumber space. Calculate the electron radiation field equation and the interface radiation field equation based on Maxwell's equations; Solving the electron radiation field equation and the interface radiation field equation yields the electron radiation field and the interface radiation field under the transverse magnetic wave polarization mode and the transverse electric wave polarization mode. The phase-matching algorithm is used to calculate the total field on both sides of the control material interface, including: calculating the spatial radiation electric field and spatial radiation magnetic field on one side of the control material interface using phase matching; and summing the electric and magnetic fields excited by the interface and the electric and magnetic fields generated by the direct radiation of the electron pulse to form the total field on both sides of the control material interface. The method of using phase matching to calculate and control the space radiation electric field and space radiation magnetic field on one side of the material interface is based on phase matching conditions. and To calculate the electric and magnetic fields of space radiation when z>0 or z<0, where , and , These are the magnetic and electric fields on either side of the interface; The boundary phase matching method is used to calculate the far-field radiation angular spectra of transverse magnetic waves and transverse electric waves excited when electrons are incident, i.e., the spatial distribution of the energy angular spectra of the transit radiation fields on both sides. The calculation of the far-field radiation angular spectra of transverse magnetic waves and transverse electric waves excited when electrons are incident includes: calculating the radiation coefficient of the electromagnetic field based on the boundary phase matching; calculating the expression of the far-field radiation angular spectrum of transverse magnetic waves using Poynting's theorem; calculating the expression of the far-field radiation angular spectrum of transverse electric waves using Poynting's theorem; and substituting the radiation coefficient of the electromagnetic field into the expressions of the far-field radiation angular spectra of transverse magnetic waves and transverse electric waves to calculate the far-field radiation angular spectra of transverse magnetic waves and transverse electric waves excited when electrons are incident. The spatial separation of the transit radiation polarization wave is controlled based on the calculated spatial distribution of the transit radiation field energy angular spectrum and the electron pulse incident angle and / or the electromagnetic parameters of the control material. This control includes: calculating the influence equation of the electron pulse incident angle on the transverse magnetic wave far-field radiation angular spectrum and the transverse electric wave far-field radiation angular spectrum based on the effect of changes in the electron pulse incident angle on the transverse magnetic wave far-field radiation angular spectrum; and adjusting the electromagnetic parameters of the control material on the effect of changes in the electromagnetic parameters of the control material on the transverse magnetic wave far-field radiation angular spectrum. The influence equations of the electromagnetic parameters of the control material are calculated based on the effects of the spectrum and the far-field radiation angle spectrum of the transverse electromagnetic wave; the influence equation of the radiation polarization wave is calculated based on the influence equation of the electron pulse incident angle and / or the influence equation of the electromagnetic parameters of the control material; the spatial distribution of the required polarization wave and the electron pulse incident angle and / or the electromagnetic parameters of the control material are calculated based on the influence equation of the radiation polarization wave, the far-field radiation angle spectrum of the transverse magnetic wave, and the far-field radiation angle spectrum of the transverse electromagnetic wave; the calculated electron pulse incident angle and / or the electromagnetic parameters of the control material are configured according to the calculated electron pulse incident angle and / or the electromagnetic parameters of the control material to obtain the required radiation polarization wave, that is, to achieve the control of the transit radiation polarization wave.

2. The method for controlling transit radiation polarization waves based on isotropic materials according to claim 1, characterized in that, The step of calculating the equivalent current based on the obliquely incident electron pulse velocity vector and converting the current to frequency and wavenumber space includes: Calculate the velocity vector of the obliquely incident electron pulse based on the incident angle of the electron pulse; Calculate the equivalent current based on the components of the velocity vector in the spatial coordinate system; The current is converted to frequency and wavenumber space to obtain the radiation characteristics at a specific frequency point.

3. The method for controlling transit radiation polarization waves based on isotropic materials according to claim 1, characterized in that, The calculation of the electron radiation field equation and the interface radiation field equation based on Maxwell's equations includes: Substitute the transformed current equation into Maxwell's equations; Calculate the electron radiation field equation and the interface radiation field equation based on Maxwell's equations.

4. The method for controlling transit radiation polarization waves based on isotropic materials according to claim 1, characterized in that, Solving the electron radiation field equation and the interface radiation field equation yields the electron radiation field and interface radiation field in the transverse magnetic wave polarization mode and the transverse electric wave polarization mode, including: Calculate the electric field radiation coefficient based on the boundary conditions; The electron radiation field is calculated based on the electron radiation field equation and the electric field radiation coefficient, including the electron radiation electric field in the transverse magnetic wave polarization mode and the electron radiation magnetic field in the transverse electric wave polarization mode. The interface radiation field is calculated based on the interface radiation field equation and the electric field radiation coefficient, including the interface radiation electric field in the transverse magnetic wave polarization mode and the interface radiation magnetic field in the transverse electric wave polarization mode.

5. A transit radiation polarization wave modulation system based on isotropic materials, characterized in that, include: A radiation control unit is used to calculate the incident angle of the electron pulse and / or control the electromagnetic parameters of the material according to the spatial distribution of the polarization wave and the control requirements of the radiation direction, and the method described in any one of claims 1-4. Electromagnetic radiation generating unit: used to emit electron pulses according to the electron pulse incident angle calculated by the radiation control unit. The electron pulses strike the control material at a uniform speed with an incident angle and a preset velocity, generating electromagnetic radiation and exciting transverse electric waves and transverse magnetic waves.

6. The transit radiation polarization wave modulation system based on isotropic materials according to claim 5, characterized in that, The transverse electric wave is an electromagnetic wave with only an electric field component in the direction perpendicular to the incident plane of the electron pulse, and the transverse magnetic wave is an electromagnetic wave with only a magnetic field component in the direction perpendicular to the incident plane of the electron pulse.

7. The transit radiation polarization wave modulation system based on isotropic materials according to claim 5, characterized in that, The control material is an isotropic material, including any one of polytetrafluoroethylene, polyethylene, and epoxy resin.

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