Terahertz wave beam regulation and control metasurface structure based on VO2 phase change and regulation and control method thereof

Abstract

The invention provides a Terahertz wave beam regulation and control metasurface structure based on VO2 phase change and a regulation and control method thereof, which can trigger local VO2 phase change through line control voltage, and combine with the arrangement design of a plurality of first super atoms, a plurality of second super atoms and a plurality of third super atoms which are sequentially stacked from top to bottom, so that the Terahertz wave beam regulation and control metasurface structure is formed. The method is obviously superior to the prior art in the aspects of multifunctional integration, dynamic response speed, hardware complexity, energy efficiency and the like, and an innovative solution is provided for multifunctional integration of terahertz communication, radar and imaging systems.

Description

Technical Field

[0001] The present invention belongs to the technical field of metasurfaces, and particularly relates to a terahertz beam steering metasurface structure based on VO2 phase change and a control method thereof. Background Art

[0002] Terahertz electromagnetic waves (Terahertz radiation) are electromagnetic waves with frequencies in the range of 0.1 to 10 terahertz (THz), and the wavelengths are approximately between 0.03 millimeters and 3 millimeters. It is located between microwaves and infrared rays, belonging to the middle region of the electromagnetic spectrum. It overlaps with millimeter waves in the long wavelength band and with infrared light in the short wavelength band. It is the transition region from macroscopic classical theory to microscopic quantum theory and also the transition region from electronics to photonics, known as the "THz gap" in the electromagnetic spectrum. Due to its unique physical properties, such as low energy, high penetrability, good fingerprint spectrum characteristics, etc., terahertz waves exhibit great application potential in the fields of communication, imaging, security inspection, biomedicine, etc. Achieving flexible amplitude modulation, beam control, frequency selection of terahertz waves is of great significance in 6G communication, intelligent sensing, radar communication, etc.

[0003] Although terahertz waves have many unique physical properties, such as low energy, high penetrability, good fingerprint spectrum characteristics, etc., which enable them to exhibit great application potential in the fields of communication, imaging, security inspection, biomedicine, etc., they also have some defects: 1. Propagation limitation: The propagation of terahertz waves is affected by factors such as atmospheric attenuation and scattering. Especially during long-distance propagation, the signal intensity will decrease significantly, which limits the application of terahertz waves in long-distance communication. 2. Moisture absorption: Terahertz waves are easily affected by moisture during propagation. Moisture will absorb the energy of terahertz waves, resulting in signal attenuation. This characteristic is particularly obvious in humid environments or biological tissues, limiting the performance of terahertz waves in some application scenarios. 3. Lack of devices: Due to the particularity of the terahertz band, traditional electronic devices and optical devices are often difficult to be directly applied to the control and detection of terahertz waves. This leads to a lack of ideal terahertz wave radiation sources, detection devices, and other functional devices, restricting the further development of terahertz technology.

[0004] A metasurface is an artificially fabricated structure that can manipulate the propagation of light to achieve various optical functions. A metasurface is the two-dimensional counterpart of metamaterials, specifically referring to the arrangement of subwavelength-sized devices in two-dimensional space to achieve specific electromagnetic properties. A metasurface consists of subwavelength unit structures that are highly degrees of freedom, aperiodic, and densely arranged in a two-dimensional plane. The shape, size, arrangement method, etc. of these unit structures can all be carefully designed to achieve flexible and effective control of characteristics such as the polarization, amplitude, phase, polarization mode, and propagation mode of electromagnetic waves. The concept of metasurfaces stems from the rethinking of traditional optical elements. They break the limitations of traditional refractive indices and shapes, bringing new possibilities to the design of optical devices. Metasurface technology has shown great potential in many fields, including imaging, sensing, communication, energy, etc. By utilizing the excellent performance of metasurfaces, more compact, efficient, and powerful optical systems can be designed, thus driving the development of optical technology into a brand-new stage.

[0005] Introducing metasurfaces to achieve the regulation of terahertz electromagnetic waves can significantly improve the performance of terahertz electromagnetic waves, and to a certain extent, make up for the defects inherent in terahertz waves themselves. Metasurfaces can precisely control characteristics such as the amplitude, phase, and polarization of terahertz waves, thereby achieving precise regulation of the beam. This helps to overcome the problem of limited terahertz wave propagation, improve the transmission efficiency and stability of signals, which helps to achieve more stable terahertz wave transmission and detection, and thus develop more powerful and stable terahertz devices. In addition, by utilizing the precise regulation ability of metasurfaces for terahertz waves, high-speed and efficient wireless communication can be achieved. Terahertz waves have a larger bandwidth and faster transmission rate. Combining with the regulation technology of metasurfaces, it is expected to achieve higher communication rates and lower latency in the future wireless communication field.

[0006] However, early metasurface designs were mainly based on fixed structures, and their electromagnetic responses were determined once the processing was completed and could not be dynamically adjusted. This non-tunable characteristic limits the flexibility of metasurfaces in practical applications. For example, it is impossible to adjust the beam direction or beam splitting mode in real time according to requirements. To solve this problem, researchers began to explore introducing tunable elements into metasurface designs to achieve dynamic electromagnetic response regulation. The selection of tunable elements is the key to designing dynamic metasurfaces. Common tunable elements include liquid crystals, graphene, phase change materials, etc. Among them, phase change materials have become an ideal choice for dynamic metasurface design due to their significant changes in electromagnetic properties and fast response characteristics. Vanadium dioxide (VO2) is a typical phase change material. The conductivity difference between its insulating state (low temperature) and metallic state (high temperature) can reach 4-5 orders of magnitude, and the phase change can be triggered by temperature, electric field, or optical excitation. This characteristic enables VO2 to achieve fast and reversible electromagnetic response regulation in metasurfaces.

[0007] At present, significant progress has been made in the dynamic control technology of terahertz waves based on metasurfaces. Multiple metasurface design schemes have demonstrated their potential in beam control and multifunctional integration. For example, some studies have triggered the phase transition of VO2 through overall heating and achieved the modulation of the transmittance of terahertz waves incident at any polarization angle in the range of 2.46 - 2.6 THz, demonstrating the excellent performance of VO2 in beam control. In addition, the frequency - polarization dual - mode VO2 metasurface unit, by combining the VO2 polarization switch and the frequency perturbation switch, realizes the dual - mode functions of polarization conversion and working frequency shift in the millimeter - wave / terahertz band, further expanding the application scenarios of metasurfaces. In the field of coded metasurfaces, the 2 - bit coding design based on VO2 controls a single - row array through voltage leads, achieving beam deflection and beam splitting functions, demonstrating the flexibility of dynamic control. At the same time, the polarization - dependent multifunctional VO2 metasurface achieves broadband absorption (efficiency > 90%) in the range of 3.0 - 3.3 THz and narrow - band absorption (efficiency > 95%) at 3.55 THz, reflecting the potential of VO2 in multifunctional integration. These schemes provide rich technical paths for the dynamic control of terahertz waves and lay an important foundation for subsequent research.

[0008] However, although these existing schemes have achieved certain breakthroughs in function realization and demonstrated the potential of terahertz wave dynamic control based on the VO2 phase transition, there is still much room for improvement in terms of multifunctional integration, dynamic control speed, and hardware complexity. For example, most of the existing technologies have single functions and slow response speeds, and can only achieve single functions of transmission, reflection, or phase modulation, lacking flexibility. Some technologies can achieve frequency selection, but the frequency range is fixed and cannot be dynamically adjusted according to requirements. There are also some technologies that are difficult to achieve high - level integration due to complex structures, which limits their promotion in practical applications.

[0009] In summary, the existing terahertz wave dynamic control technology based on the VO2 phase transition faces challenges in many aspects such as single function, complex excitation, and high hardware implementation difficulty. These challenges not only limit the multifunctional integration ability and practical application scenarios of metasurface devices but also hinder the further development of terahertz technology in fields such as communication, radar, and imaging. Therefore, how to overcome these challenges and achieve efficient, flexible, and fast control of terahertz waves is one of the important research topics in current terahertz technology. Summary of the Invention

[0010] Based on this, in view of the above - mentioned technical problems, a terahertz beam control metasurface structure based on the VO2 phase transition and its control method are provided.

[0011] The technical solution adopted by the present invention is as follows:

[0012] As a first aspect of the present invention, there is provided a terahertz beam steering metasurface structure based on VO2 phase transition, which is characterized in that it includes a plurality of supercells arranged periodically. The supercell includes a plurality of first meta-atoms, a plurality of second meta-atoms, and a plurality of third meta-atoms stacked in sequence from top to bottom, and the numbers of the three are the same. The first meta-atom, the second meta-atom, and the third meta-atom all include a substrate, a resonant ring, and a metal wire for powering the meta-atom where it is located. The substrate is a cubic block, and one side in the front-back direction is an installation surface. The installation surfaces of the substrates of the first meta-atom, the second meta-atom, and the third meta-atom are on the same side. The resonant ring and the metal wire are arranged on the installation surface of the corresponding substrate. The center line of the resonant ring is in the front-back direction. The resonant rings of the first meta-atom, the second meta-atom, and the third meta-atom are in the same position on the corresponding installation surface. The resonant ring is spliced by a metal part and a VO2 thin film part along its circumferential direction. When the meta-atom is powered on, the VO2 thin film part undergoes a phase transition, causing a phase change in the resonant ring where it is located. The phases of the resonant rings of each meta-atom satisfy: when powering on the first meta-atom and the third meta-atom, and not powering on the second meta-atom, the absolute value of the phase difference between the second meta-atom and the first meta-atom and the absolute value of the phase difference between the third meta-atom and the second meta-atom are both 120° ± 30°. When powering on the second meta-atom, and not powering on the first meta-atom and the third meta-atom, the absolute value of the phase difference between the third meta-atom and the second meta-atom is 0° ± 30°, and the absolute values of the phase differences between the third meta-atom and the second meta-atom and the first meta-atom are both 180° ± 30°.

[0013] As a second aspect of the present invention, there is provided a terahertz beam steering method for the metasurface structure according to the first aspect above, which is characterized in that it includes:

[0014] When beam deflection is required, power on all the first meta-atoms and the third meta-atoms of the metasurface structure, and do not power on all the second meta-atoms;

[0015] When beam splitting is required, power on all the second meta-atoms of the metasurface structure, and do not power on all the first meta-atoms and the third meta-atoms.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] 1. Existing metasurface designs based on VO2 phase transition usually only support a single function (such as beam deflection or polarization conversion), lacking the ability of multifunctional integration. However, the metasurface structure provided by the embodiments of the present application can flexibly switch between beam deflection and beam splitting in the same device, breaking through the limitation of the single function of the prior art;

[0018] 2. Most existing solutions rely on overall heating or light-controlled triggering of VO2 phase transition, with a relatively slow response time (>1 ms), making it difficult to achieve local rapid response, and with relatively large energy loss. However, the metasurface structure provided by the embodiments of the present application can trigger local phase transition by applying voltage to the wires of the meta-atoms, with a single-row response time <100 ns, enabling fast dynamic regulation, avoiding the problems of slow response speed and energy loss caused by overall heating or light control, and meeting the requirements of high-speed communication and radar systems;

[0019] 3. The existing coded metasurface design requires a complex feeding network, and it is difficult to independently control a large-scale array, with a high hardware implementation cost. It is necessary to configure a control line for each unit separately, resulting in complex wiring (for example, a 60×60 array requires 3,600 control lines), and high hardware implementation difficulty. However, for the metasurface structure provided by the embodiments of the present application, since each meta-atom has a wire, a simplified design based on a row control architecture (the wires of the meta-atoms in the same row are connected to one control line) can be adopted. Then, by optimizing the wire layout and feeding method, the hardware complexity can be significantly reduced. For example, a 60×60 array only requires 60 control lines, and the wiring complexity is reduced by 98%. At the same time, it supports fast refreshing driven by FPGA (>1 kHz).

[0020] In summary, the present invention can trigger local VO2 phase transition by row control voltage. Combining the arrangement design of multiple first meta-atoms, multiple second meta-atoms, and multiple third meta-atoms stacked in sequence from top to bottom, it is significantly superior to the existing technology in terms of multifunctional integration, dynamic response speed, hardware complexity, energy efficiency, etc., providing an innovative solution for the multifunctional integration of terahertz communication, radar, and imaging systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention will be described in detail below with reference to the drawings and specific embodiments:

[0022] Figure 1 It is a top view structural schematic diagram of a terahertz beam steering metasurface structure based on VO2 phase transition provided by an embodiment of the present invention;

[0023] Figure 2 It is a front view structural schematic diagram of a terahertz beam steering metasurface structure based on VO2 phase transition provided by an embodiment of the present invention;

[0024] Figure 3 It is a structural schematic diagram of a supercell provided by an embodiment of the present invention;

[0025] Figure 4 It is a structural schematic diagram of the resonant ring of the first meta-atom provided by an embodiment of the present invention;

[0026] Figure 5 It is a structural schematic diagram of the resonant ring of the second meta-atom provided by an embodiment of the present invention;

[0027] Figure 6 Schematic diagram of the resonant ring of the third superatom in the embodiment of the present invention;

[0028] Figure 7 Schematic diagram of the far-field observation beam deflection effect in the embodiment of the present invention;

[0029] Figure 8 Schematic diagram of the far-field observation beam splitting effect in the embodiment of the present invention. Detailed implementation manners

[0030] The following will describe the embodiments of the present invention with reference to the accompanying drawings of the specification. It should be noted that the embodiments involved in this specification are not exhaustive and do not represent the only embodiments of the present invention. The following corresponding embodiments are only for clearly explaining the inventive content of the present invention and do not limit its implementation manners. For those of ordinary skill in the art, different forms of changes and modifications can be made based on the description of this embodiment, and any obvious changes or modifications that belong to the technical concept and inventive content of the present invention are also within the protection scope of the present invention.

[0031] As Figure 1 and Figure 2 shown, the embodiment of the present application provides a terahertz beam control metasurface structure based on VO2 phase change, including a plurality of supercells 1100 arranged periodically.

[0032] In this embodiment, a plurality of supercells 1100 are arranged in the left-right direction and the up-down direction, and the distance between adjacent supercells 1100 is 0.

[0033] As Figure 3 shown, in this embodiment, the supercell 1100 includes 2 first superatoms 1110, 2 second superatoms 1120, and 2 third superatoms 1130 stacked in sequence from top to bottom. The number of the three is the same. Of course, the number of the three can also be selected to be more than 2.

[0034] The overall composition of the above superatoms is the same. Taking the first superatom 1110 as an example, it includes a substrate 1111, a resonant ring 1112, and a metal wire 1113 (such as a gold wire).

[0035] In this embodiment, the substrate 1111 is a cubic block, made of sapphire material (dielectric constant is 9.61), quartz material (dielectric constant is 3.5 - 8.1), or silicon material (dielectric constant is 11.7).

[0036] The front side of the base of each superatom is the mounting surface, and the resonant ring and the metal wire are disposed on the mounting surface of the corresponding base. In this embodiment, the mounting surface of the base is square, with a side length of 158 μm, and the thickness of the base in the front-rear direction is 500 μm.

[0037] In this embodiment, the resonant ring and the metal wire are formed on the mounting surface by photolithography technology.

[0038] The center line of the resonant ring is in the front-rear direction, and the center of the resonant ring of each superatom coincides with the center of the corresponding mounting surface, so as to ensure that the resonant rings of each superatom are in the same position on the corresponding mounting surface. Of course, the center of the resonant ring may not coincide with the center of the corresponding mounting surface.

[0039] Among them, the resonant rings are all square rings, with a ring width of 7 μm and a thickness of 200 nm in the front-rear direction. The resonant rings of each superatom are integrally formed by splicing a metal part and a VO2 thin film part along their circumferential direction. The metal part is made of aluminum, and the thicknesses of the metal part and the VO2 thin film part in the front-rear direction are both 200 nm. The difference is that the specific dimensions and positional relationships are different, which will be specifically described below.

[0040] As Figure 4 shown, the side length of the resonant ring 1112 of the first superatom 1110 is 92 μm, which includes a first metal part 1112a and a first VO2 thin film part 1112b. The first metal part 1112a constitutes the upper left part of the resonant ring 1112, and the first VO2 thin film part 1112b constitutes the lower right part of the resonant ring 1112. The upper side segment and the left side segment of the first metal part 1112a respectively have first slits 1112c in the up-down direction and the left-right direction. The two first slits 1112c are symmetric along the upper left-lower right diagonal of the resonant ring 1112. The width of the first slit 1112c is 4 μm, and the distance between the first slit 1112c and the upper left corner point of the resonant ring 1112 is 35 μm. The lower side segment and the right side segment of the first VO2 thin film part 1112b are symmetric along the above diagonal, and the lengths of the lower side segment and the right side segment are both 51 μm.

[0041] As Figure 5As shown, the side length of the resonant ring 1121 of the second superatom 1120 is 90 μm. It includes a second metal part 1121a and a second VO2 thin film part 1121b. The second metal part 1121a is in a square ring shape. Its upper side segment and left side segment respectively have second slits 1121c in the up-down direction and left-right direction. The two second slits 1121c are symmetric along the upper-left to lower-right diagonal of the resonant ring 1121. The width of the second slit is 4 μm, and its distance from the upper-left corner point of the resonant ring 1121 is 61 μm. The lower side segment of the second metal part 1121a has a third slit in the up-down direction. The distance between the third slit and the lower-left corner point of the resonant ring 1121 is 17 μm. The second VO2 thin film part 1121b is filled in the third slit, and its length is 9 μm.

[0042] As Figure 6 shown, the side length of the resonant ring of the third superatom 1130 is 88 μm. Its structure is the same as that of the resonant ring of the first superatom 1110, and also includes a first metal part and a first VO2 thin film part. Its upper side segment and left side segment of the first metal part also respectively have first slits in the up-down direction and left-right direction. The width of the first slit is 4 μm. The difference is that the distance between the first slit and the upper-left corner point of the resonant ring is 61 μm. The lengths of the lower side segment and the right side segment of the first VO2 thin film part are both 66 μm.

[0043] The metal wire is used to apply voltage so that the superatom where it is located is powered on. In this embodiment, the metal wire is arranged in the left-right direction. Its upper edge is flush with the upper edge of the corresponding mounting surface. The length of the metal wire is equal to the side length of the mounting surface, and the width is 15 μm. In order to avoid coupling, the distance between the metal wire and the resonant ring is not less than the ring width of the resonant ring.

[0044] When the superatom is not powered on, the VO2 thin film part is in an insulating state. When the superatom is powered on, the current excites the nearby Joule heat, which is transferred to the VO2 thin film part through the substrate, triggering the VO2 phase change. The VO2 thin film part transforms into a metallic state. At this time, the resonant ring is equivalent to a closed metal ring, causing its resonant frequency to shift.

[0045] Based on the specific dimensions and positional relationships of the above-mentioned resonant rings, the phases of the resonant rings of each superatom satisfy: in a super cell 1100, when the first superatom 1110 and the third superatom 1130 are powered on and the second superatom 1120 is not powered on, the absolute value of the phase difference between the second superatom 1120 and the first superatom 1110 and the absolute value of the phase difference between the third superatom 1130 and the second superatom 1120 are both approximately 120°, forming a linear phase gradient to achieve beam deflection. See Figure 7; When the second meta - atom 1120 is powered on, and the first meta - atom 1110 and the third meta - atom 1130 are not powered on, the absolute value of the phase difference between the third meta - atom 1130 and the second meta - atom 1120 is approximately 0°, and the absolute values of the phase differences between the third meta - atom 1130 and the second meta - atom 1120 and the first meta - atom 1110 are both approximately 180°, forming a non - linear phase gradient to achieve beam splitting. See Figure 8 . Among them, according to the requirements of the industry content difference application (beamforming), the absolute value of the above - mentioned phase difference only needs to satisfy the approximate phase gradient (the error can be tolerated up to ±30°).

[0046] Figure 7 and Figure 8 is a simulated and emulated metasurface array. The incident wave is along the negative Z - axis direction, and a far - field monitor is added at 0.568 THz. The observed three - dimensional far - field pattern. Among them, the up - and - down direction is the Z - axis, the left - and - right direction is the Y - axis, and the direction perpendicular to the XZ plane is the X - axis. The three form the polarization coordinate system of the three - dimensional far - field pattern.

[0047] Therefore, the beam control process of the metasurface structure in the embodiment of the present application is as follows:

[0048] When beam deflection is required, all the first meta - atoms and the third meta - atoms of the metasurface structure are powered on, and all the second meta - atoms are not powered on.

[0049] When beam splitting is required, all the second meta - atoms of the metasurface structure are powered on, and all the first meta - atoms and the third meta - atoms are not powered on.

[0050] As can be seen from the above, compared with the prior art, a terahertz beam control metasurface structure based on VO2 phase change provided by the embodiment of the present application has the following beneficial effects:

[0051] 1. Existing metasurface designs based on VO2 phase change usually only support a single function (such as beam deflection or polarization conversion), lacking the ability of multi - function integration. However, the metasurface structure provided by the embodiment of the present application can flexibly switch between beam deflection and beam splitting in the same device, breaking through the limitation of the single function of the prior art;

[0052] 2. Existing solutions mostly rely on overall heating or light - controlled triggering of VO2 phase change, with a relatively slow response time (>1 ms), difficult to achieve local rapid response, and large energy loss. However, the metasurface structure provided by the embodiment of the present application can trigger local phase change by applying voltage to the wires of the meta - atoms, with a single - line response time <100 ns, achieving fast dynamic control, avoiding the problems of slow response speed and large energy loss caused by overall heating or light control, and meeting the requirements of high - speed communication and radar systems;

[0053] 3. Existing coded metasurface designs require complex feeding networks, making it difficult to independently control large-scale arrays, with high hardware implementation costs. Separate control lines need to be configured for each unit, resulting in complex wiring (for example, a 60×60 array requires 3,600 control lines), and high hardware implementation difficulty. However, for the metasurface structure provided in the embodiments of the present application, since each meta-atom has a wire, a simplified design based on a row control architecture (the wires of the meta-atoms in the same row are connected to one control line) can be adopted. Furthermore, by optimizing the wire layout and feeding method, the hardware complexity can be significantly reduced. For example, a 60×60 array only requires 60 control lines, and the wiring complexity is reduced by 98%. At the same time, it supports fast refreshing driven by FPGA (>1 kHz).

[0054] In summary, the terahertz beam steering metasurface structure based on VO2 phase transition provided in the embodiments of the present application can trigger local VO2 phase transition through row control voltage, and combined with the arrangement design of multiple first meta-atoms, multiple second meta-atoms, and multiple third meta-atoms stacked in sequence from top to bottom, it is significantly superior to the prior art in terms of multi-functional integration, dynamic response speed, hardware complexity, energy efficiency, etc., providing an innovative solution for the multi-functional integration of terahertz communication, radar, and imaging systems.

[0055] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application is also intended to include these changes and modifications.

Claims

1. A terahertz beam control metasurface structure based on VO2 phase transition, characterized in that, It includes a plurality of supercells arranged periodically. The supercells include a plurality of first superatoms, a plurality of second superatoms, and a plurality of third superatoms stacked in sequence from top to bottom, and the numbers of the three are the same. The first superatoms, the second superatoms, and the third superatoms all include a substrate, a resonant ring, and a metal wire for powering the superatom where it is located. The substrate is a cubic block, and one side in the front-back direction is an installation surface. The installation surfaces of the substrates of the first superatoms, the second superatoms, and the third superatoms are located on the same side. The resonant ring and the metal wire are arranged on the installation surfaces of the corresponding substrates. The center line of the resonant ring is in the front-back direction. The positions of the resonant rings of the first superatoms, the second superatoms, and the third superatoms on the corresponding installation surfaces are the same. The resonant ring is formed by splicing a metal part and a VO2 thin film part along its circumferential direction. When the superatom is powered on, the VO2 thin film part undergoes a phase change to change the phase of the resonant ring where it is located. The phases of the resonant rings of each superatom satisfy: when powering on the first superatoms and the third superatoms and not powering on the second superatoms, the absolute values of the phase differences between the second superatoms and the first superatoms and between the third superatoms and the second superatoms are both 120°±30°; when powering on the second superatoms and not powering on the first superatoms and the third superatoms, the absolute value of the phase difference between the third superatoms and the second superatoms is 0°±30°, and the absolute values of the phase differences between the third superatoms and the second superatoms and the first superatoms are both 180°±30°.

2. The terahertz beam steering metasurface structure based on VO2 phase transition according to claim 1, characterized in that The resonant ring is a square ring with a ring width of 7μm; The resonant rings of the first superatoms and the third superatoms both include a first metal part and a first VO2 thin film part. The first metal part constitutes the upper left part of the resonant ring, and the first VO2 thin film part constitutes the lower right part of the resonant ring. The upper side segment and the left side segment of the first metal part respectively have first slits in the up-down direction and the left-right direction. The two first slits are symmetric along the upper left-lower right diagonal of the resonant ring. The width of the first slit is 4μm. The lower side segment and the right side segment of the first VO2 thin film part are symmetric along the diagonal. Among them, for the first superatom, the side length of its resonant ring is 92μm, the distance between the first slit and the upper left corner point of the resonant ring is 35μm, and the lengths of the lower side segment and the right side segment are both 51μm. For the third superatom, the side length of its resonant ring is 88μm, the distance between the first slit and the upper left corner point of the resonant ring is 61μm, and the lengths of the lower side segment and the right side segment are both 66μm; The resonant ring of the second superatom includes a second metal part and a second VO2 thin film part. The second metal part is in a square ring shape, and its upper side segment and left side segment respectively have second slits in the up-down direction and left-right direction. The two second slits are symmetric along the upper-left to lower-right diagonal of the resonant ring. The lower side segment of the second metal part has a third slit in the up-down direction. The second VO2 thin film part is filled in the third slit. The side length of the resonant ring is 90 μm, the width of the second slit is 4 μm, and its distance from the upper-left corner point of the resonant ring is 61 μm. The distance between the third slit and the lower-left corner point of the resonant ring is 17 μm, and the length of the second VO2 thin film part is 9 μm.

3. The terahertz beam steering metasurface structure based on VO2 phase transition according to claim 1, wherein The multiple supercells are arranged in the left-right direction and the up-down direction, and the spacing between adjacent supercells is 0.

4. A terahertz beam steering metasurface structure based on VO2 phase transition according to claim 1, characterized in that, The substrate is made of sapphire, quartz, or silicon.

5. A terahertz beam steering metasurface structure based on VO2 phase transition according to claim 2, characterized in that The mounting surface of the substrate is square, with a side length of 158 μm, and the thickness of the substrate in the front-back direction is 500 μm.

6. The terahertz beam steering metasurface structure based on VO2 phase transition according to claim 2, characterized in that, The centers of the resonant rings of the first superatom, the second superatom, and the third superatom coincide with the centers of the corresponding mounting surfaces.

7. The terahertz beam steering metasurface structure based on VO2 phase transition according to claim 2, characterized in that The metal wire is arranged in the left-right direction, and its upper edge is flush with the upper edge of the corresponding mounting surface. The length of the metal wire is equal to the side length of the mounting surface, and the distance between the metal wire and the resonant ring is not less than the ring width of the resonant ring.

8. The terahertz beam steering metasurface structure based on VO2 phase transition according to claim 7, characterized in that The width of the metal wire is 15 μm.

9. The terahertz beam steering metasurface structure based on VO2 phase transition according to claim 2, characterized in that The thickness of the resonant ring in the front-back direction is 200 nm.

10. A terahertz beam control method for a terahertz beam control metasurface structure based on VO2 phase change according to any one of claims 1-9, characterized in that, Comprising: When beam deflection is required, power on all the first superatoms and the third superatoms of the metasurface structure, and do not power on all the second superatoms. When beam splitting is required, power on all the second superatoms of the metasurface structure, and do not power on all the first superatoms and the third superatoms.

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