Dual-band intelligent heat emitter based on vanadium dioxide super surface

Abstract

The application discloses a kind of dual-band intelligent heat emitters based on vanadium dioxide super surface, it is related to infrared thermal management super surface technical field, its structure is from bottom to top in turn bottom layer, middle layer and surface layer, middle layer includes embedded cross vanadium dioxide structure, surface layer is Ti / VO2 composite pattern layer.In mid-wave infrared (3-5 μm) band, device keeps stable emissivity under low temperature state (313K) and high temperature state (353K), and is not sensitive to VO2 phase transition response, and constitutes the heat safety channel of continuous radiation heat dissipation.In 7.50-17.36 μm band, device realizes super wideband emissivity regulation using VO2 phase transition, high temperature state emissivity is as high as 0.97, modulation depth reaches 0.76, and regulation bandwidth reaches 9.86 μm.

Description

Technical Field

[0001] This invention relates to the field of infrared thermal management metasurface technology, and more specifically to a dual-band intelligent thermal emitter based on a vanadium dioxide metasurface. Background Technology

[0002] In recent years, thermal radiation modulation technology has received widespread attention and rapid development, demonstrating significant application potential in fields such as spacecraft thermal management, infrared detection, and target recognition. According to the Stefan-Boltzmann law, an object's radiative heat dissipation capacity is proportional to the fourth power of its surface emissivity and absolute temperature; therefore, dynamically controlling surface emissivity is a core strategy for achieving efficient thermal management. Early research on thermal radiation modulation mainly relied on static structures to achieve selective absorption or emission in specific wavelength bands. However, static thermal control coatings, due to their fixed emission characteristics, are difficult to adapt to dynamic heat loads and cannot meet the multifunctional thermal management requirements under complex environments. Thermal radiation modulation devices covering the mid-wave infrared (MWIR: 3-5 μm) and long-wave infrared (LWIR: 8-14 μm) atmospheric windows have significant practical value in fields such as infrared night vision, gas detection, and adaptive thermal management.

[0003] Compared to precious metals such as gold and silver, titanium has a wider infrared response band. Its ohmic loss characteristics in the mid-infrared band are conducive to achieving broadband high emissivity, and it has good chemical stability, making it one of the ideal metallic materials for constructing broadband infrared thermal radiation metasurfaces.

[0004] Vanadium dioxide (VDC) has attracted considerable attention due to its reversible metal-insulator (IMT) phase transition near 340 K, which is accompanied by a conductivity jump of several orders of magnitude, providing a physical basis for active emissivity switching. However, most current VDC thermal control devices are still limited to a global switching mode, suppressing emissivity across the entire wavelength range at low temperatures. This results in a lack of a continuously conducting radiative heat dissipation path, posing a potential challenge to thermal management reliability. The intelligent thermal control device designed in this invention possesses numerous advantages, including dual-band functional decoupling, a phase transition-insensitive stable emission channel, ultra-wideband emissivity switching, and polarization independence. Summary of the Invention

[0005] Therefore, the purpose of this invention is to provide a vanadium dioxide metasurface intelligent thermal management device that covers the mid-wave infrared and long-wave infrared bands, achieves dual-band decoupled thermal radiation control, and is insensitive to incident polarization and angle. It primarily targets the 3-5μm and 7.50-17.36μm bands for dual-band intelligent thermal radiation control.

[0006] The device of this invention exhibits good polarization independence and wide-angle incident robustness, and has important application prospects in the fields of spacecraft thermal management, thermal protection of high-power electronic devices, and adaptive thermal management in complex atmospheric environments.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A dual-band intelligent thermal emitter based on vanadium dioxide metasurface includes several metasurface emitting units, which are periodically and repeatedly arranged in two mutually perpendicular directions in a plane. Each metasurface emitting unit includes a reflective substrate layer, an intermediate layer, and a surface layer. The reflective substrate layer is a metal substrate; The intermediate layer includes: a lower dielectric layer and an upper dielectric layer; The upper dielectric layer has a cross-shaped patch embedded in it, and the bottom surface of the cross-shaped patch is on the same plane as the bottom surface of the upper dielectric layer. The surface layer includes a square patch and four trapezoidal patches; The square patch and the four trapezoidal patches are all disposed on the top of the upper dielectric layer; The metasurface emission unit is shaped like a quadrangular prism, with four trapezoidal patches located on the four sides of the square patch. The narrow end of each trapezoidal patch faces the square patch, and the wide end is centered and aligned with the boundary of the upper dielectric layer.

[0008] Preferably, the metal substrate has a thickness of h1; h1 = 0.2 μm; The lower dielectric layer has a thickness of h2; h2 = 0.6 μm; The cross-shaped patch has a thickness of h3; h3 = 0.1 μm; The upper dielectric layer has a thickness of h4; h4 = 0.6 μm; The square patch and the four trapezoidal patches have a thickness of h5; h5 = 0.1 μm.

[0009] Preferably, the metal substrate is titanium; the upper dielectric layer and the lower dielectric layer are silicon dioxide; the square patch is made of titanium; and the trapezoidal patch is made of vanadium dioxide.

[0010] Preferably, the material of the cross-shaped patch is vanadium dioxide.

[0011] Preferably, the square patch has a side length of L, where L = 0.65 μm; the trapezoidal patch has an upper base width of w1, where w1 = 0.1 μm, a lower base width of w2, where w2 = 0.8 μm, and a height of w3, where w3 = 0.5 μm. The planar dimensions of the metasurface emitting unit have a period of P = 1.8 μm in both length and width.

[0012] Preferably, the cross-shaped patch has a long arm length of l, l=1.2μm, a short arm width of w=0.6μm, and a thickness of 0.1μm.

[0013] As can be seen from the above technical solution, compared with the prior art, the present invention has the following technical effects: This invention employs a titanium substrate with a thickness exceeding its skin depth as the bottom layer, confining electromagnetic energy within the cavity to form a standing wave, serving as the high-reflectivity lower boundary of the Fabry-Perot resonator. The intermediate spacer layer is made of silicon dioxide, which has an extremely small imaginary dielectric part in the mid-infrared band, concentrating radiation loss between the upper and lower metal layers. The thickness of the silicon dioxide determines the cavity length of the Fabry-Perot resonator. The intermediate resonant layer uses cross-shaped vanadium dioxide to ensure polarization insensitivity. The top layer pattern consists of a titanium patch and four trapezoidal vanadium dioxide prisms around it. The titanium patch utilizes its ohmic loss to dissipate the locally enhanced electric field energy within the cavity as thermal radiation, contributing significantly to the emissivity in the mid-infrared band. The four trapezoidal vanadium dioxide prisms distributed around the titanium patch, with their narrow ends and the difference in gap width between the gap and the edge of the titanium patch, excite localized surface plasmon resonance modes at different resonant frequencies. The superposition of these multiple modes expands the response bandwidth.

[0014] In the 353K metallic state, cross-shaped and trapezoidal vanadium dioxide serve as the lower and upper metal layers of the metal-insulator-metal structure, respectively, forming an antiparallel current loop and exciting long-wave infrared magnetic polariton resonance. In the 313K insulating state, vanadium dioxide degenerates into a transparent dielectric, suppressing the magnetic polariton resonance. The device retains only the localized surface plasmon resonance and Fabry-Perot cavity resonance dominated by the titanium patch. Through the above material combination and pattern design, the device forms a stable thermal radiation emission channel insensitive to the vanadium dioxide phase transition in the 3–5 μm mid-wave infrared band, and achieves ultra-wideband active switching control with an average emissivity ranging from 0.21 to 0.97 in the 7.50–17.36 μm long-wave infrared band.

[0015] This invention achieves emissivity of 0.69 in the insulating state (313K) and 0.67 in the metallic state (353K) within the 3-5μm mid-wave infrared band, with a modulation difference of only 0.02 between the two states, forming a thermally safe channel. In the 7.50–17.36μm band, the average emissivity of the metallic state reaches as high as 0.97, with a continuous high emission bandwidth of 9.86μm; the average emissivity of the insulating state decreases to 0.21, with an emissivity modulation depth of 0.76. According to Kirchhoff's law of thermal radiation, under thermal equilibrium conditions, the emissivity of an object equals its absorptivity, i.e., ε=A. The absorptivity is calculated as A=1-RT, where A is the absorptivity, R is the reflectivity, and T is the transmittance. Since the thickness of the underlying metal substrate is 0.2μm, much greater than the skin depth in the infrared band, electromagnetic waves cannot pass through it; therefore, the transmittance T=0, and the expression simplifies to ε=A=1-RT.

[0016] This invention is insensitive to changes in the polarization angle of the light source. When incident normally, the transverse electric polarization and transverse magnetic polarization responses in the two phase states are completely consistent. Regardless of the polarization direction of the light, the emissivity remains almost unchanged.

[0017] This invention exhibits excellent robustness to changes in incident angle. Within the 0°–40° range, the emissivity in the mid-wave and long-wave infrared bands remains almost constant. When the incident angle increases to 60°, the average emissivity of the two polarizations in the 8–14 μm band remains above 0.88. Throughout the entire 0°–60° angle range, the dual-state emissivity switching ratio consistently exceeds 2.5, indicating that this structure possesses wide-angle applicability.

[0018] The device of this invention can construct a phase-change-independent thermal safety channel in the 3-5μm mid-wave infrared band and realize a high-modulation-depth intelligent thermal radiation emission switch in the 7.50–17.36μm ultra-wide band. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0020] Figure 1 The following are schematic diagrams of the structure of the present invention: (a) a three-dimensional structural diagram, (b) a top view of a unit cell, (c) a side view of a unit cell, and (d) a cross-shaped structural diagram. In the diagram: 1-Reflective substrate; 2-Lower dielectric layer; 3-Cross-shaped patch; 4-Upper dielectric layer; 5-Square patch; 6-Trapezoidal patch; Figure 2 (a) Real and (b) Imaginary parts of the relative permittivity of vanadium dioxide as a function of wavelength at 313 K and 353 K; Figure 3 Normalized impedance curves of the proposed structure in (a) the insulating state and (b) the metallic state; Figure 4 The emissivity of the device at high and low temperatures; Figure 5 Electromagnetic field distribution for the thermal safety channel mechanism: (a) top-view electric field, (b) side-view electric field, and (c) side-view magnetic field at λ1=3.89μm in the insulating state (313K); (d) top-view electric field, (e) side-view electric field, and (f) side-view magnetic field at λ2=3.76μm in the metallic state (353K). Figure 6 The magnetic field and current vector distribution of the ultra-wideband switching mechanism are shown in (a) top view magnetic field diagram, (b) cross-sectional magnetic field diagram of the cross patch and (c) side view magnetic field diagram at λ3=11.98μm in the metallic state (353K). Figure 7(a) Spectral emissivity of different square patch side lengths at 313K, (b) Spectral emissivity of different square patch side lengths at 353K, (c) Spectral emissivity of different interlayer thicknesses at 313K, (d) Spectral emissivity of different interlayer thicknesses at 353K. Figure 8 (a) Spectral emissivity of different short arm widths of cross-shaped patches at 353K; (b) Spectral emissivity of different long arm lengths of cross-shaped patches at 353K; (c) Spectral emissivity of different metasurface emission unit period lengths at 353K; (d) Spectral emissivity of different ambient refractive indices at 353K. Figure 9 Two-dimensional color maps showing the emissivity as a function of incident angle (0°–60°) and wavelength (3–18 μm): (a) 313 K insulating state transverse magnetic polarization, (b) 313 K insulating state transverse electric polarization, (c) 353 K metallic state transverse magnetic polarization, and (d) 353 K metallic state transverse electric polarization. Detailed Implementation

[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example 1

[0022] This invention provides a vanadium dioxide metasurface intelligent thermal emitter that covers key mid-wave infrared and long-wave infrared bands, achieves dual-band decoupled thermal radiation modulation, and is insensitive to incident polarization and angle.

[0023] In the simulation settings, a plane wave was used for perpendicular incidence, the background refractive index was set to 1.0, and the wavelength range for solving was set to 3–18 μm.

[0024] To simulate periodic structures, the boundary conditions along the x and y axes are set to periodic boundary conditions to simulate infinitely repeating unit structures. The boundary condition along the z-axis uses a perfectly matched layer absorption boundary condition to effectively eliminate non-physical reflections. According to Kirchhoff's law of thermal radiation, the spectral emissivity of an object in thermal equilibrium is numerically equal to its spectral absorptivity, i.e., ε(λ) = A(λ), and the absorptivity is calculated as A = 1 - RT.

[0025] The relative permittivity of silicon dioxide is taken as 3.9. The reflective substrate 1 uses titanium, which has high loss characteristics. Combined with the top-layer patterned structure, it can more easily achieve broadband absorption. Its permittivity is described by the Drud-Lorentz model. The optical permittivity of vanadium dioxide is modeled using a Drud-like formula.

[0026] like Figure 1 (a) shows a three-dimensional view of the metasurface emission unit. The reflective substrate 1 is a titanium substrate, above which are a lower dielectric layer 2 and an upper dielectric layer 4 (both made of silicon dioxide). A cross-shaped patch 3 resonator (made of vanadium dioxide) is embedded in the upper dielectric layer 4. Above the upper dielectric layer 4 is the top layer pattern, which consists of a square patch 5 (made of titanium) and four trapezoidal patches 6 (made of vanadium dioxide) symmetrically distributed around it. The top view is shown below. Figure 1 As shown in (b), the side view is as follows Figure 1 As shown in (c), the cross-shaped patch 3 structure diagram is as follows: Figure 1 As shown in (d).

[0027] like Figure 2 The figure shows the real and imaginary parts of the relative permittivity of vanadium dioxide at 313 K and 353 K as a function of wavelength. As the temperature increases from 313 K to 353 K, vanadium dioxide undergoes a transformation from an insulating phase to a metallic phase. The real part of the permittivity decreases rapidly, while the imaginary part shows the opposite upward trend. The optical properties differ significantly between the two phases.

[0028] like Figure 3 The normalized impedance curves of the metasurface emitting unit in the insulating and metallic states are shown. When the real part of the normalized impedance approaches 1 and the imaginary part approaches 0, impedance matching occurs between the device and free space, and the emissivity correspondingly approaches 1. In the insulating state (313 K), the real part of the normalized impedance at λ1 = 3.89 μm approaches 1, and the imaginary part approaches zero, precisely corresponding to the absorption peak in the emissivity spectrum. In the metallic state (353 K), impedance matching is observed at λ2 = 3.76 μm and λ3 = 11.98 μm, respectively, precisely corresponding to the two absorption peaks in the emissivity spectrum.

[0029] like Figure 4The figure shows the emissivity curves of the metasurface emitting unit at high and low temperatures. In the metallic state (353 K), the device exhibits an emissivity exceeding 0.90 in the 3.22–3.98 μm and 7.50–17.36 μm wavelength ranges, with an average emissivity as high as 0.98 within the 8–14 μm atmospheric window, approaching the radiation characteristics of an ideal blackbody. In the insulating state (313 K), the emissivity exceeds 0.90 in the 3.33–4.13 μm wavelength range, while the emissivity in the 7.50–17.36 μm wavelength range is significantly suppressed, with an average emissivity of only 0.21. In the 3–5 μm wavelength range, the average emissivities in the two phase states are 0.67 and 0.69, respectively, with a modulation difference of only 0.02, forming a thermally safe channel independent of the phase transition state. In the 7.50–17.36 μm band, the average emissivity of the metallic and insulating states are 0.97 and 0.21, respectively, with a modulation depth of 0.76 and a continuous high transmit bandwidth of 9.86 μm. Through rational design of device structural parameters and material selection, a dual-band decoupled thermal management function of stable mid-wave infrared emission and ultra-wideband active modulation of long-wave infrared has been achieved, showing significant application prospects in spacecraft thermal control, thermal protection of high-power electronic devices, and adaptive thermal management.

[0030] To analyze the transmission mechanism of each functional band in greater depth, Figure 5 and Figure 6 The electromagnetic field distributions at the three characteristic wavelengths are given respectively.

[0031] exist Figure 5 In (a), (b), and (c), the electric field at λ1 = 3.89 μm is highly concentrated in the gap between the edge of the square patch 5 and the narrow end of the trapezoidal patch 6, indicating that the local surface plasmon resonance at the edge of the square patch 5 is the dominant mechanism for electric field confinement in this band. The side-view electric field shows a gradually increasing distribution along the z-axis within the intermediate layer, indicating that a Fabry-Perot cavity resonance is formed between the titanium back reflective layer (reflective substrate 1) and the top metal pattern (surface layer). The magnetic field peak is concentrated near the interface between the reflective substrate 1 and the lower dielectric layer 2, further verifying the existence of Fabry-Perot cavity standing waves. Figure 5 In (d), (e), and (f), the electromagnetic field distribution at λ2 = 3.76 μm in the metallic state is highly consistent with that in the insulating state, indicating that the dominant resonance mode in this band is insensitive to the vanadium dioxide phase transition. According to the Ohmic loss principle, the energy dissipation in this band is dominated by the titanium structure in both phase states. The imaginary part of the dielectric of vanadium dioxide is too small to significantly affect the resonance mode, which is the physical basis for the formation of the thermal safety channel.

[0032] Figure 6 The magnetic field and current vector distributions at λ3 = 11.98 μm in the metallic state (353 K) are given. From... Figure 6(a) It can be seen that the induced current flows along the +x direction on the square patch 5 and the trapezoidal patch 6, indicating that the metallic trapezoidal patch 6 has actively carried the induced current as a plasmonic resonator. Figure 6 (b) The presence of magnetic field hotspots at the four inner corners of the three-layer cross-shaped patch indicates that the three-layer cross-shaped patch actively participates in the metal-insulator-metal current loop. Figure 6 (c) In the side view, the top titanium / vanadium dioxide patterned layer and the three cross-shaped patch layers form antiparallel currents. The magnetic field energy is highly concentrated inside the silicon dioxide cavity, exciting the unique magnetic polariton resonance of the metal-insulator-metal structure. Figure 5 The magnetic field characteristics of the Fabry-Perot resonance in the middle form a stark contrast. When vanadium dioxide is in an insulating state, the three layers of the cross-shaped patch cannot maintain an effective induced current, the magnetic polariton resonance is completely suppressed, resulting in a sharp drop in emissivity in the long-wave infrared band.

[0033] The influence of various geometric parameters on the dual-band transmission performance in the complete structure was analyzed. Figure 7 and Figure 8 This illustrates that different geometric parameters have varying degrees of influence on emission performance. When discussing changes in any one of the following parameters, the other parameters remain constant. For example... Figure 7 As shown in (a) and (b), with the increase of the side length L of the square patch, the long-wave emission peak in the mid-infrared band exhibits a monotonically redshifted, while the short-wave peak position remains essentially unchanged with L. This indicates that the long-wave peak originates from localized surface plasmon resonance of the titanium patch, and its resonance wavelength is dominated by the patch size. The emission spectrum shapes in the mid-infrared band are almost identical under both temperature states, verifying the phase transition insensitivity of the thermal safety channel. In the 7.50–17.36 μm band, the emissivity corresponding to each L value remains low in the insulating state. In the metallic state, when L is too large, the top metal filling ratio exceeds the critical value, resulting in a sharp narrowing of the high emissivity bandwidth in the long-wave band and a significant performance degradation. Figure 7 As shown in (c) and (d), with the increase of the interlayer thickness, the peak position in the mid-infrared band redshifts overall. This corresponds precisely to the short-wave peak that remains unchanged when L changes, proving that this peak is determined by the Fabry-Perot cavity resonance, and the change in cavity thickness causes the overall resonant frequency within the cavity to shift. In the 7.50–17.36 μm band, the widest continuous high emissivity bandwidth is obtained when the interlayer thickness in the metallic state is 1.2 μm. When the interlayer thickness is too small or too large, the metal-insulator-metal upper cavity spacing deviates from the optimal value, and the bandwidth decreases accordingly.

[0034] like Figure 8As shown in (a) and (b), the width w of the short arm of the cross-shaped patch 3 and the length l of the long arm of the cross-shaped patch 3 have almost no effect on the spectral changes in the mid-wave infrared band, but both exhibit significant bandwidth changes in the 7.50–17.36 μm band, proving the decoupled design of the dual-band function. With increasing w, the high emissivity bandwidth gradually increases and tends to saturate; with increasing l, the longest-wavelength resonant peak continues to redshift, and the high emissivity coverage extends towards the long-wavelength end. Optimal broadband coverage is achieved when l = 1.2 μm; when l is too large, the peak redshifts outside the simulation window, and the high emissivity coverage on the long-wavelength side degrades sharply. Figure 8 As shown in (c), with the increase of the metasurface emitting unit period P (the side length of the metasurface emitting unit), the high emissivity bandwidth in the 7.50–17.36 μm band shows a trend of first increasing and then decreasing. When P = 1.8 μm, all performance parameters reach their optimal levels. When P is too small or too large, the near-field coupling conditions between the metal patches deviate from the optimal level, and the broadband high emissivity performance degrades. Figure 8 As shown in (d), when the ambient refractive index changes from 1.0 to 1.5, the emission performance of both the mid-wave infrared and long-wave infrared bands remains basically stable, and the device exhibits good environmental robustness.

[0035] Based on the above optimization analysis, the final structural parameters are determined as follows: h1=0.2μm, h2=h4=0.6μm, h3=h5=0.1μm, L=0.65μm, l=1.2μm, w=0.6μm, w1=0.1μm, w2=0.8μm, w3=0.5μm, P=1.8μm.

[0036] Figure 9 Two-dimensional colorimetric diagrams are presented showing the emissivity as a function of incident angle (0°–60°) and wavelength (3–18 μm). The transverse magnetic polarization and transverse electric polarization responses are completely consistent in the two-phase states under normal incidence, demonstrating the fourfold rotational symmetry of the unit cell structure and indicating that the metasurface emitting unit cell is insensitive to the polarization of the light source. Figure 9 The four figures show the angular responses of transverse magnetic polarization and transverse electric polarization in the two-phase states, respectively. In the mid-infrared band, the device is insensitive to both angle and polarization within the 0°–40° range, consistent with the localized characteristics of surface plasmon resonance in the titanium patch. Its resonant frequency is determined by the patch size and is independent of the incident wave vector. In the 353K metallic state, the average emissivity of 8–14 μm remains above 0.96 for both polarizations within the 0°–40° range, stemming from the angle-insensitive characteristics of the subwavelength metal-insulator-metal cavity magnetic polarization resonance. As the incident angle continues to increase to 60°, the transverse electric polarization emissivity remains relatively stable, while the transverse magnetic polarization emissivity decreases. However, the overall performance of both polarizations remains at a high level; at 60°, the average emissivity of the 8–14 μm polarizations still reaches 0.88, and the dual-state switching ratio exceeds 2.5 throughout the 0°–60° range, indicating that the device's thermal management function is effectively maintained under large-angle incident conditions.

[0037] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0038] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A dual-band intelligent thermal emitter based on a vanadium dioxide metasurface, comprising a plurality of metasurface emitting units, wherein the plurality of metasurface emitting units are periodically and repeatedly arranged in two mutually perpendicular directions in a plane, characterized in that, The metasurface emission unit includes a reflective substrate layer, an intermediate layer, and a surface layer; The reflective substrate layer is a metal substrate; The intermediate layer includes: a lower dielectric layer and an upper dielectric layer; The upper dielectric layer has a cross-shaped patch embedded in it, and the bottom surface of the cross-shaped patch is on the same plane as the bottom surface of the upper dielectric layer. The surface layer includes a square patch and four trapezoidal patches, all of which are disposed on top of the upper dielectric layer; The metasurface emission unit is generally in the shape of a quadrangular prism, with four trapezoidal patches located on the four sides of the square patch. The narrow end of each trapezoidal patch faces the square patch, and the wide end is centered and aligned with the boundary of the upper dielectric layer. The square patch is made of titanium, and the four trapezoidal patches and the cross-shaped patch are all made of vanadium dioxide. Furthermore, the titanium square patch is used to form a stable thermal radiation emission channel in the 3–5 μm mid-wave infrared band that is insensitive to the vanadium dioxide phase transition.

2. The dual-band intelligent thermal emitter based on vanadium dioxide metasurface according to claim 1, characterized in that: The metal substrate has a thickness of h1; h1 = 0.2 μm; The lower dielectric layer has a thickness of h2; h2 = 0.6 μm; The cross-shaped patch has a thickness of h3; h3 = 0.1 μm; The upper dielectric layer has a thickness of h4; h4 = 0.6 μm; The square patch and the four trapezoidal patches have a thickness of h5; h5 = 0.1 μm.

3. The dual-band intelligent thermal emitter based on vanadium dioxide metasurface according to claim 2, characterized in that, The metal substrate is titanium; both the upper and lower dielectric layers are silicon dioxide.

4. The dual-band intelligent thermal emitter based on vanadium dioxide metasurface according to claim 2, characterized in that, The square patch has a side length of L, L=0.65μm; the trapezoidal patch has an upper base width of w1, w1=0.1μm, a lower base width of w2, w2=0.8μm, and a height of w3, w3=0.5μm; the planar dimensions of the metasurface emitting unit are both periodic P=1.8μm.

5. The dual-band intelligent thermal emitter based on vanadium dioxide metasurface according to claim 2, characterized in that, The cross-shaped patch has a long arm length of l, l=1.2μm, a short arm width of w=0.6μm, and a thickness of 0.1μm.

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