Multi-mode vortex electromagnetic wave generator

Abstract

The invention discloses a multi-mode vortex electromagnetic wave generator. The multi-mode vortex electromagnetic wave generator comprises metasurface condition displacement operators with the adjustable number and metasurface coin throwing operators with the adjustable number. The metasurface condition displacement operator comprises a first dielectric substrate, a first metal layer and a second dielectric substrate; a plurality of first metal sheets are arranged on the first dielectric substrate, the plurality of first metal sheets are arranged at a first gradient rotation angle, and the plurality of first metal sheets are all cross-shaped; a plurality of first holes are formed in the first metal layer, and a plurality of second metal sheets are arranged in the plurality of first holes; the metasurface coin throwing operator comprises a third dielectric substrate, a second metal layer and a fourth dielectric substrate; a plurality of third metal sheets are arranged on the third dielectric substrate, the plurality of third metal sheets are arranged at a second gradient rotation angle, and the plurality of third metal sheets are cuboids; a plurality of second holes are formed in the second metal layer, and a plurality of fourth metal sheets are arranged in the second holes.

Description

Technical Field

[0001] The present application relates to the technical field of electromagnetic wave generators, and in particular to a multi-mode vortex electromagnetic wave generator. Background Art

[0002] An electromagnetic wave generator is a device used to generate electromagnetic waves. In the related art, after the structure of the electromagnetic wave generator is fixed, the mode number of the generated vortex electromagnetic wave is correspondingly fixed, and it is impossible to generate vortex electromagnetic waves with multiple mode numbers. Summary of the invention

[0003] The present application aims to propose a multi-mode vortex electromagnetic wave generator capable of generating vortex electromagnetic waves with multiple modes.

[0004] The embodiment of the present application provides a multi-mode vortex electromagnetic wave generator, comprising:

[0005] A metasurface conditional displacement operator with adjustable quantity, the metasurface conditional displacement operator comprising a first dielectric substrate, a first metal layer, and a second dielectric substrate which are sequentially stacked; a plurality of first metal sheets are arranged on the first dielectric substrate, the plurality of first metal sheets are arranged at a first gradual rotation angle, and the plurality of first metal sheets are all cross-shaped; a plurality of first holes are arranged on the first metal layer, a plurality of second metal sheets are arranged in the plurality of first holes, the plurality of second metal sheets correspond to the plurality of first metal sheets in quantity and position, the plurality of second metal sheets are arranged at the first gradual rotation angle, and the plurality of second metal sheets are all cross-shaped;

[0006] A metasurface coin-tossing operator with adjustable quantity, the metasurface coin-tossing operator comprising a third dielectric substrate, a second metal layer and a fourth dielectric substrate stacked in sequence; a plurality of third metal sheets are arranged on the third dielectric substrate, the plurality of third metal sheets are arranged at a second gradual rotation angle, and the plurality of third metal sheets are all rectangular parallelepipeds; a plurality of second holes are arranged on the second metal layer, a plurality of fourth metal sheets are arranged in the plurality of second holes, the plurality of fourth metal sheets correspond in quantity and position to the plurality of third metal sheets, the plurality of fourth metal sheets are arranged at the second gradual rotation angle, and the plurality of fourth metal sheets are all rectangular parallelepipeds.

[0007] According to some embodiments of the present application, both the first gradual rotation angle and the second gradual rotation angle are adjustable.

[0008] According to some embodiments of the present application, the first gradual rotation angle and the second gradual rotation angle are both 45°.

[0009] According to some embodiments of the present application, the material of the first dielectric substrate and the second dielectric substrate is any one of FR-4 and silicon dioxide.

[0010] According to some embodiments of the present application, the material of the third dielectric substrate and the fourth dielectric substrate is any one of FR-4 and silicon dioxide.

[0011] According to some embodiments of the present application, the material of the first metal layer is any one of gold, silver and copper.

[0012] According to some embodiments of the present application, the material of the second metal layer is any one of gold, silver and copper.

[0013] According to some embodiments of the present application, the axes of the hypersurface conditional displacement operator and the hypersurface coin tossing operator coincide with each other.

[0014] According to some embodiments of the present application, the first metal sheet includes a first strip portion and a second strip portion that cross each other, the length of the first strip portion is 5.8 mm, the width of the first strip portion is 1.1 mm, the thickness of the first strip portion is 0.2 mm, the length of the second strip portion is 4.5 mm, the width of the second strip portion is 1.1 mm, and the thickness of the second strip portion is 0.2 mm.

[0015] According to some embodiments of the present application, the length of the third metal sheet is 5.8 mm, the width of the third metal sheet is 1.1 mm, and the thickness of the third metal sheet is 0.2 mm.

[0016] In the embodiment of the present application, by stacking metasurface conditional displacement operators and metasurface coin tossing operators and changing the number of metasurface conditional displacement operators and metasurface coin tossing operators, vortex electromagnetic waves with multiple modes can be generated.

[0017] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present application is further described below with reference to the accompanying drawings and embodiments, wherein:

[0019] Figure 1 A schematic diagram of the structure of a multi-mode vortex electromagnetic wave generator provided in an embodiment of the present application;

[0020] Figure 2 A schematic diagram of the structural decomposition of the hypersurface conditional displacement operator provided in an embodiment of the present application;

[0021] Figure 3 A schematic diagram of the structural decomposition of the hypersurface coin tossing operator provided in an embodiment of the present application;

[0022] Figure 4A schematic structural diagram of a first dielectric substrate of a metasurface conditional displacement operator provided in an embodiment of the present application;

[0023] Figure 5 A schematic diagram of the structure of the first metal layer of the supersurface conditional displacement operator provided in an embodiment of the present application;

[0024] Figure 6 A schematic structural diagram of a third dielectric substrate of a metasurface coin tossing operator provided in an embodiment of the present application;

[0025] Figure 7 A schematic diagram of the structure of the second metal layer of the metasurface coin tossing operator provided in an embodiment of the present application;

[0026] Figure 8 A diagram showing the energy distribution simulation test results of the vortex electromagnetic wave generated by the multi-mode vortex electromagnetic wave generator provided in an embodiment of the present application when the number of transmissions is one;

[0027] Fig. 9 A diagram showing the energy distribution simulation test results of the vortex electromagnetic waves generated by the multi-mode vortex electromagnetic wave generator provided in an embodiment of the present application when the number of transmissions is two;

[0028] Fig.10 A diagram showing the energy distribution simulation test results of the vortex electromagnetic waves generated by the multi-mode vortex electromagnetic wave generator provided in an embodiment of the present application when the number of transmissions is three;

[0029] Fig.11 A diagram showing the energy distribution simulation test results of the vortex electromagnetic waves generated by the multi-mode vortex electromagnetic wave generator provided in an embodiment of the present application when the number of transmissions is four;

[0030] Fig.12 A diagram showing the energy distribution simulation test results of the vortex electromagnetic waves generated by the multi-mode vortex electromagnetic wave generator provided in an embodiment of the present application when the number of transmissions is five.

[0031] Reference numerals:

[0032] Metasurface conditional displacement operator 100, first dielectric substrate 110, first metal layer 120, second dielectric substrate 130, first metal sheet 140, second metal sheet 150, first hole 160, metasurface coin tossing operator 200, third dielectric substrate 210, second metal layer 220, fourth dielectric substrate 230, third metal sheet 240, fourth metal sheet 250, second hole 260. DETAILED DESCRIPTION

[0033] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0034] In the description of the present application, it should be understood that the descriptions involving orientation, such as the orientation or positional relationship indicated as up, down, etc., are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0035] In the description of this application, "a plurality" means more than two. If there is a description of "first" or "second", it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0036] In the description of this application, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in this application based on the specific content of the technical solution.

[0037] Orbital Angular Momentum (OAM) is mainly used in the following fields:

[0038] 1. Communication technology field: Wireless communication mainly relies on the dimension of electric field intensity of plane electromagnetic waves. With the continuous iterative development of science and technology, the time domain, frequency domain, code domain, spatial domain and polarization domain, which are used to improve spectrum efficiency, have gradually shown a saturation trend and are limited by the MIMO capacity boundary. For this reason, it is urgent to develop new dimensions. It is of great significance to break through the classic transmission method of plane electromagnetic waves from the perspective of the physical characteristics of electromagnetic waves. The use of OAM as a new dimension of wireless communication is characterized by the fact that the number of OAM modes will not change after direct radiation, reflection and scattering, which gets rid of the energy divergence problem of traditional vortex electromagnetic waves and is suitable for long-distance multiplexing transmission.

[0039] 2. Optical imaging: In optical imaging, OAM is used to improve image resolution and the ability to detect fine structures. The OAM characteristics of light beams can be used to achieve ultra-high-resolution microscopy imaging, lidar imaging and other applications.

[0040] 3. Quantum information processing: OAM is used to realize the encoding and transmission of quantum bits. By controlling the OAM state of photons, more efficient quantum computing and safer quantum communication can be achieved.

[0041] 4. Material processing: The OAM state of the beam can be used to achieve precise cutting of materials, providing a more efficient laser processing method. At the same time, by regulating the OAM state of the beam, micro-nano processing of materials can be further achieved, providing a new development direction for the fields of nanotechnology and photonics.

[0042] At present, the methods for generating vortex electromagnetic waves can be divided into the following categories. The first category: using a stepped spiral phase plate to convert a plane wavefront into a spiral wavefront, which has a simple structure but high processing accuracy and is mainly used in high-frequency bands; the second category: using spiral phase feeding in an array structure antenna to generate vortex electromagnetic waves, which can be used in microwave bands with lower frequencies, but the antenna structure and feeding structure are quite complex, especially when the number of OAM electromagnetic wave modes is large, it is extremely difficult to achieve; the third category: using a circular traveling waveguide with orthogonal feeding to realize vortex electromagnetic waves, but the number of vortex electromagnetic wave modes and the operating frequency will be fixed with the structure, and the flexibility is low; the fourth category: generating vortex electromagnetic waves based on artificial surface plasmons, which also requires fine design and precision processing.

[0043] However, after the structure of the existing electromagnetic wave generator is fixed, the pattern of the vortex electromagnetic wave generated is correspondingly fixed, and the flexibility is low.

[0044] In order to solve the above problems, the present application proposes a multi-mode vortex electromagnetic wave generator.

[0045] Refer to the following Figures 1 to 12 A multi-mode vortex electromagnetic wave generator according to an embodiment of the present application is described.

[0046] The present application embodiment provides a multi-mode vortex electromagnetic wave generator, such as Figure 1 As shown, including:

[0047] The number of adjustable metasurface conditional displacement operators 100, such as Figure 2 As shown, the metasurface conditional displacement operator 100 includes a first dielectric substrate 110, a first metal layer 120, and a second dielectric substrate 130 which are stacked in sequence. Figure 4 As shown, a plurality of first metal sheets 140 are disposed on the first dielectric substrate 110, and the plurality of first metal sheets 140 are arranged at a first gradually rotating angle, and the plurality of first metal sheets 140 are all in a cross shape. Figure 5 As shown, a plurality of first holes 160 are disposed on the first metal layer 120, and a plurality of second metal sheets 150 are disposed in the plurality of first holes 160. The number and position of the plurality of second metal sheets 150 correspond to the plurality of first metal sheets 140. The plurality of second metal sheets 150 are arranged at a first gradually rotating angle, and the plurality of second metal sheets 150 are all cross-shaped;

[0048] The number of tunable metasurface coin tossing operators 200, such as Figure 3 As shown, the metasurface coin tossing operator 200 includes a third dielectric substrate 210, a second metal layer 220, and a fourth dielectric substrate 230 which are stacked in sequence. Figure 6 As shown, a plurality of third metal sheets 240 are disposed on the third dielectric substrate 210, and the plurality of third metal sheets 240 are arranged at a second gradual rotation angle, and the plurality of third metal sheets 240 are all rectangular parallelepipeds. Figure 7 As shown, a plurality of second holes 260 are disposed on the second metal layer 220, a plurality of fourth metal sheets 250 are disposed in the plurality of second holes 260, the number and position of the plurality of fourth metal sheets 250 correspond to the plurality of third metal sheets 240, the plurality of fourth metal sheets 250 are arranged at a second gradual rotation angle, and the plurality of fourth metal sheets 250 are all rectangular prisms.

[0049] The multi-mode vortex electromagnetic wave generator provided in the embodiment of the present application has a simple structure and does not require redesign. It can generate multi-mode vortex electromagnetic waves by simply stacking the metasurface conditional displacement operator 100 and the metasurface coin tossing operator 200 and changing the number of the metasurface conditional displacement operator 100 and the metasurface coin tossing operator 200.

[0050] In some embodiments of the present application, the second metal layer 220 of the metasurface coin tossing operator 200 is used to adjust the phase.

[0051] In one embodiment of the present application, both the first gradual rotation angle and the second gradual rotation angle are adjustable.

[0052] In this embodiment, by adjusting the first gradual rotation angle and the second gradual rotation angle of the metasurface coin tossing operator 200 and the conditional displacement operator, a vortex electromagnetic wave with asymmetric energy distribution of each mode number can be generated.

[0053] In an embodiment of the present application, the first gradual rotation angle and the second gradual rotation angle are both 45°.

[0054] In this embodiment, when the first gradual rotation angle and the second gradual rotation angle are both 45°, a vortex electromagnetic wave with symmetrical energy distribution of each mode number can be generated.

[0055] In an embodiment of the present application, the material of the first dielectric substrate 110 and the second dielectric substrate 130 is any one of FR-4 and silicon dioxide.

[0056] In one embodiment of the present application, the material of the third dielectric substrate 210 and the fourth dielectric substrate 230 is any one of FR-4 and silicon dioxide.

[0057] In one embodiment of the present application, the material of the first metal layer 120 is any one of gold, silver and copper. The first metal layer 120 may also be made of other good conductor materials.

[0058] In one embodiment of the present application, the material of the second metal layer 220 is any one of gold, silver and copper. The second metal layer 220 may also be made of other good conductor materials.

[0059] In one embodiment of the present application, Figure 1 As shown, the first dielectric substrate 110, the first metal layer 120, the second dielectric substrate 130, the third dielectric substrate 210, the second metal layer 220 and the fourth dielectric substrate 230 are all disc-shaped, and the axes of the metasurface conditional displacement operator 100 and the metasurface coin tossing operator 200 coincide.

[0060] In some embodiments of the present application, the metasurface conditional displacement operator 100 and the metasurface coin tossing operator 200 are arranged in concentric circles and fixed by a square truss.

[0061] In one embodiment of the present application, Figure 2 As shown, the first metal sheet 140 includes a first strip portion and a second strip portion that cross each other, the length of the first strip portion is 5.8 mm, the width of the first strip portion is 1.1 mm, the thickness of the first strip portion is 0.2 mm, the length of the second strip portion is 4.5 mm, the width of the second strip portion is 1.1 mm, and the thickness of the second strip portion is 0.2 mm.

[0062] In one embodiment of the present application, Figure 2 As shown, the second metal sheet 150 and the first metal sheet 140 have the same shape and size.

[0063] According to some embodiments of the present application, the length of the third metal sheet 240 is 5.8 mm, the width of the third metal sheet 240 is 1.1 mm, and the thickness of the third metal sheet 240 is 0.2 mm.

[0064] In one embodiment of the present application, Figure 3 As shown, the fourth metal sheet 250 and the third metal sheet 240 have the same shape and size.

[0065] The implementation principle of the present application based on quantum walk is explained below.

[0066] A classical optical system simulating discrete-time quantum walk is established using a metasurface. The coin space is represented by the orthogonal polarization state of the incident beam, and the position space of the walker is represented by the orbital angular momentum mode number. The conditional displacement operator and coin tossing operator are respectively realized through the design of the metasurface structure. The mathematical model of the metasurface conditional displacement operator 100 in classical optics is:

[0067]

[0068] Among them, Q is a quantity related to the particle energy, |l> is the OAM eigenstate, |L> is the left-hand circularly polarized wave, and |R> is the right-hand circularly polarized wave.

[0069] The conditional displacement operator will generate a vortex electromagnetic wave with a positive or negative mode number according to the left-hand or right-hand direction of the circularly polarized wave, which is equivalent to taking a step in quantum walk according to the state of the coin.

[0070] The mathematical model of the hypersurface coin tossing operator 200 is:

[0071]

[0072] Among them, |L> is a left-hand circularly polarized wave, |R> is a right-hand circularly polarized wave, It is a superposition state of left-hand and right-hand circularly polarized waves.

[0073] The metasurface coin tossing operator 200 can convert the left-handed or right-handed circularly polarized wave in the beam after the conditional displacement operator into a superposition state of uniform left-handed and right-handed circularly polarized waves. By superimposing the mathematical models of the metasurface conditional displacement operator 100 and the metasurface coin tossing operator 200, the following mathematical model can be obtained:

[0074]

[0075] Among them, |l+2q>, |l-2q> are OAM eigenstates, representing the addition or subtraction of the vortex electromagnetic wave mode number, respectively. They are the superposition states of left-hand circularly polarized wave and right-hand circularly polarized wave respectively.

[0076] This mathematical model describes the generation process of vortex electromagnetic waves.

[0077] The mathematical model of quantum walk is:

[0078]

[0079] Among them, H is the coin tossing operation, I is the unit operator acting on the walker, S is the conditional walk operator, which means that the walker takes a step left or right according to the state of the coin, |j+1> represents the grid point position, is the spin state of the particle.

[0080] By comparing the mathematical model of the superposition of the metasurface conditional displacement operator 100 and the metasurface coin tossing operator 200 with the mathematical model of quantum walk, it is not difficult to see that their mathematical forms are consistent. In quantum walk, the position state of the walker can be marked by the OAM mode in the beam, and the mode number of the vortex electromagnetic wave generated after multiple transmissions and the proportion of vortex electromagnetic waves of each mode number can be calculated.

[0081] Therefore, quantum walking can be realized in OAM space, and it is feasible to simulate the process of quantum walking with a light beam. By using the metasurface conditional displacement operator 100 and the metasurface coin tossing operator 200 and freely combining them, it is finally possible to flexibly generate multi-mode vortex electromagnetic waves based on the idea of ​​quantum walking.

[0082] like Figures 8 to 12 The multi-mode vortex electromagnetic wave generator provided in the embodiment of the present application is respectively provided with a super-surface conditional displacement operator 100 and a super-surface coin tossing operator 200, and the energy distribution simulation test results of the generated vortex electromagnetic waves when the number of transmissions is one to five. Under different transmission times, the energy proportion of each mode number of the vortex electromagnetic waves of different mode numbers of the multi-mode vortex electromagnetic wave generator provided in the embodiment of the present application is shown in Table 1.

[0083] Table 1. Energy proportion of each mode number of vortex electromagnetic waves

[0084]

[0085] The embodiments of the present application are described in detail above in conjunction with the accompanying drawings, but the present application is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present application.

Claims

1. A multi-mode vortex electromagnetic wave generator, characterized in that: include: A metasurface conditional displacement operator with an adjustable number, wherein the metasurface conditional displacement operator comprises a first dielectric substrate, a first metal layer, and a second dielectric substrate which are sequentially stacked; A plurality of first metal sheets are arranged on the first dielectric substrate, the plurality of first metal sheets are arranged at a first gradual rotation angle, and the plurality of first metal sheets are all cross-shaped; a plurality of first holes are arranged on the first metal layer, a plurality of second metal sheets are arranged in the plurality of first holes, the plurality of second metal sheets correspond to the plurality of first metal sheets in number and position, the plurality of second metal sheets are arranged at the first gradual rotation angle, and the plurality of second metal sheets are all cross-shaped; A metasurface coin-tossing operator with adjustable quantity, the metasurface coin-tossing operator comprising a third dielectric substrate, a second metal layer and a fourth dielectric substrate stacked in sequence; a plurality of third metal sheets are arranged on the third dielectric substrate, the plurality of third metal sheets are arranged at a second gradual rotation angle, and the plurality of third metal sheets are all rectangular parallelepipeds; a plurality of second holes are arranged on the second metal layer, a plurality of fourth metal sheets are arranged in the plurality of second holes, the plurality of fourth metal sheets correspond in quantity and position to the plurality of third metal sheets, the plurality of fourth metal sheets are arranged at the second gradual rotation angle, and the plurality of fourth metal sheets are all rectangular parallelepipeds.

2. The multi-mode vortex electromagnetic wave generator according to claim 1, characterized in that: The first gradual rotation angle and the second gradual rotation angle are both adjustable.

3. The multi-mode vortex electromagnetic wave generator according to claim 1, characterized in that: The first gradual rotation angle and the second gradual rotation angle are both 45°.

4. The multi-mode vortex electromagnetic wave generator according to claim 1, characterized in that: The material of the first dielectric substrate and the second dielectric substrate is any one of FR-4 and silicon dioxide.

5. The multi-mode vortex electromagnetic wave generator according to claim 1, characterized in that: The material of the third dielectric substrate and the fourth dielectric substrate is any one of FR-4 and silicon dioxide.

6. The multi-mode vortex electromagnetic wave generator according to claim 1, characterized in that: The material of the first metal layer is any one of gold, silver and copper.

7. The multi-mode vortex electromagnetic wave generator according to claim 1, characterized in that: The material of the second metal layer is any one of gold, silver and copper.

8. The multi-mode vortex electromagnetic wave generator according to claim 1, characterized in that: The axes of the hypersurface conditional displacement operator and the hypersurface coin tossing operator coincide.

9. The multi-mode vortex electromagnetic wave generator according to claim 1, characterized in that: The first metal sheet includes a first strip portion and a second strip portion that cross each other, the length of the first strip portion is 5.8 mm, the width of the first strip portion is 1.1 mm, the thickness of the first strip portion is 0.2 mm, the length of the second strip portion is 4.5 mm, the width of the second strip portion is 1.1 mm, and the thickness of the second strip portion is 0.2 mm.

10. The multi-mode vortex electromagnetic wave generator according to claim 1, characterized in that: The length of the third metal sheet is 5.8 mm, the width of the third metal sheet is 1.1 mm, and the thickness of the third metal sheet is 0.2 mm.

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