Single-layer metasurface structure

Abstract

The embodiment of the application discloses a single-layer metasurface structure for simultaneously realizing low reflection of near-infrared and far-infrared laser, low infrared radiation and heat management, the single-layer metasurface structure comprising a bottom continuous metal film, an intermediate dielectric film layer and a top discrete metal layer; the bottom continuous metal film layer is used for realizing total reflection of electromagnetic waves so that the transmittance is zero; the intermediate dielectric film layer is used for introducing resonant absorption at a wavelength of 10.6 mu m and controlling the phase of the incident electromagnetic wave reflected by the bottom continuous metal film by adjusting the thickness thereof; the top discrete metal layer is arranged on the intermediate dielectric film layer and is used for forming a reflection phase difference of the incident electromagnetic wave in the metal region and the non-metal region to realize regulation and control of the near-infrared electromagnetic wave scattering field wave front and is also used for introducing localized surface plasmon resonance to realize infrared selective absorption.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of multi-band electromagnetic wave regulation, and in particular to a single-layer metasurface structure for simultaneously realizing low reflection of near-infrared and far-infrared laser, low infrared radiation, and thermal management. BACKGROUND

[0002] The rapid development of optoelectronic technology has enabled the widespread application of advanced optoelectronic reconnaissance, and laser-infrared composite detection technology combines the respective advantages of laser active detection and infrared passive detection, posing new challenges to low detectable technology. Laser detectors use electromagnetic waves with wavelengths of 0.9 μm, 1.064 μm, 1.31 μm, 1.55 μm, and 10.6 μm for high-precision detection by emitting electromagnetic waves to the target and analyzing the return signal. The corresponding low-detectable materials need to have the ability to reduce the intensity of the target scattering echo. To achieve low detectability for passive infrared detectors, the material usually needs to have low emissivity, which corresponds to low absorption. However, full-band low infrared emissivity will hinder the heat dissipation of the device, causing thermal instability. Single-layer metasurfaces are compatible with mature planar processes, have the advantages of simple preparation and low cost. However, current single-layer metasurfaces have relatively single functions and are difficult to simultaneously realize low reflection of multi-wavelength laser, low infrared radiation, and broadband thermal management. SUMMARY

[0003] Therefore, it is necessary to propose a single-layer metasurface structure to solve the above problems.

[0004] The present application provides a single-layer metasurface structure for simultaneously realizing low reflection of near-infrared and far-infrared laser, low infrared radiation, and thermal management,

[0005] The single-layer metasurface structure comprises a bottom continuous metal film, an intermediate dielectric film layer, and a top discrete metal layer.

[0006] The bottom continuous metal film layer is used to realize total reflection of electromagnetic waves, making the transmittance zero.

[0007] The intermediate dielectric film layer is used to introduce resonant absorption at a wavelength of 10.6 μm and control the phase of the incident electromagnetic wave reflected by the bottom continuous metal film by adjusting the thickness thereof.

[0008] The top discrete metal layer is arranged on the intermediate dielectric film layer and is used to form a reflection phase difference between the metal region and the non-metal region to realize regulation of the near-infrared electromagnetic wave scattering field wavefront and introduce localized surface plasmon resonance to realize infrared selective absorption.

[0009] In the scheme, the material of the bottom continuous metal film is gold, silver, aluminum, chromium or platinum; the thickness of the bottom continuous metal film is t1 and t1≥80nm.

[0010] In the scheme, the intermediate dielectric film layer is a silicon dioxide material; the thickness of the intermediate dielectric film layer is t2 and 0.1μm≤t2≤0.2μm.

[0011] In the scheme, the material of the top discrete metal layer is gold, silver, aluminum, chromium or platinum; the thickness of the top discrete metal layer is t3 and 0.08μm≤t3≤0.2μm.

[0012] In the scheme, the top discrete metal layer comprises a plurality of array units, and the array units are arranged periodically on the intermediate dielectric film layer.

[0013] In the scheme, each of the array units comprises at least one metal disc.

[0014] In the scheme, the period of the periodic pattern of the array units is p and 6.4μm≤p≤7.6μm; each of the array units comprises four metal discs with different diameters; the diameters of the four metal discs are d1, d2, d3 and d4 respectively, and 1.6μm≤d1≤2.6μm, 1.6μm≤d2≤2.6μm, 1.6μm≤d3≤2.6μm, 1.6μm≤d4≤2.6μm; the centers of the four metal discs are located at (p / 4, p / 4), (-p / 4, p / 4), (-p / 4, -p / 4) and (p / 4, -p / 4) respectively.

[0015] By using the embodiment of the present application, the following beneficial effects are achieved:

[0016] The present application introduces phase control to control the scattering field characteristics of laser by introducing phase control in the classical metal-dielectric layer-metal structure, so as to realize low reflection of near-infrared waveband laser; the dielectric constant mutation of the intermediate dielectric film layer near 10.6μm wavelength is used to introduce resonance absorption, so as to reduce the reflectivity of far-infrared laser; the top discrete metal layer is used to realize selective absorption in the infrared non-atmospheric window (5-8μm), so as to maintain low radiation characteristics in the infrared atmospheric window and perform effective broadband thermal management. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0018] Wherein:

[0019] Figure 1 A structural schematic diagram of a single-layer metasurface structure of the present application;

[0020] Figure 2 A amplitude and phase modulation characteristic diagram of an array unit in the single-layer metasurface structure of the present application is provided with a metal disc;

[0021] Figure 3 A amplitude and phase modulation characteristic diagram of an array unit in the single-layer metasurface structure of the present application is provided with two, three, six metal discs, respectively;

[0022] Figure 4 A three-dimensional schematic diagram of an array unit in the single-layer metasurface structure of Example 1;

[0023] Figure 5 A front view of an array unit in the single-layer metasurface structure of Example 1;

[0024] Figure 6 A top view of an array unit in the single-layer metasurface structure of Example 1;

[0025] Figure 7 A reflectivity simulation result of the single-layer metasurface structure of Example 1 in the 0.8-1.6 μm wavelength band under normal incidence;

[0026] Figure 8 A far-field scattering simulation result of the single-layer metasurface structure of Example 1 under normal incidence of 1.06 μm laser;

[0027] Figure 9 An absorption (emissivity) simulation result of the single-layer metasurface structure of Example 1 in the 3-14 μm wavelength band under normal incidence;

[0028] Figure 10 A dielectric constant of the silicon dioxide material in the 3-14 μm wavelength band of Example 1;

[0029] Figure 11 An analog electromagnetic field distribution diagram of the single-layer metasurface structure of Example 1 under wavelengths λ1 and λ2;

[0030] Figure 12 An analog electromagnetic field distribution diagram of the single-layer metasurface structure of Example 1 under wavelengths λ3 and λ4;

[0031] Figure 13 A preparation and performance characterization result diagram of the single-layer metasurface structure of Example 1. DETAILED DESCRIPTION

[0032] Clearly, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts fall within the protection scope of the present application.

[0033] The embodiment of the present application provides a single-layer metasurface structure for simultaneously realizing low reflection of near-infrared and far-infrared laser, low infrared radiation and heat management, such as Figure 1 As shown in the figure, the single-layer metasurface structure comprises a bottom continuous metal film 1, an intermediate dielectric film layer 2 and a top discrete metal layer 3.

[0034] The bottom continuous metal film layer 1 is used to realize total reflection of electromagnetic waves so that the transmittance is zero.

[0035] The intermediate dielectric film layer 2 is used to introduce resonant absorption at a wavelength of 10.6 μm, and the phase of the incident electromagnetic wave after reflection by the bottom continuous metal film 1 is controlled by adjusting the thickness thereof.

[0036] The top discrete metal layer 3 is arranged on the intermediate dielectric film layer 2, and is used to form a reflection phase difference between the metal region and the non-metal region to realize regulation of the near-infrared electromagnetic wave scattering field wavefront, and is also used to introduce localized surface plasmon resonance to realize infrared selective absorption.

[0037] The present application introduces phase regulation to control the scattering field characteristics of laser in the classical metal-dielectric layer-metal structure, realizes low reflection of near-infrared laser, introduces resonant absorption by using the dielectric constant mutation of the intermediate dielectric film layer 2 near the wavelength of 10.6 μm to further reduce the reflectivity of far-infrared laser, and the top discrete metal layer 3 is a horizontal cascade of metal discs with different diameters, so as to realize selective absorption in the infrared non-atmospheric window (5-8 μm), thereby maintaining the low radiation characteristics in the infrared atmospheric window while performing effective broadband heat management.

[0038] The material of the bottom continuous metal film 1 is gold, silver, aluminum, chromium or platinum; the thickness of the bottom continuous metal film 1 is t1 and t1 is greater than or equal to 80 nm.

[0039] The intermediate dielectric film layer 2 is a silicon dioxide material; the thickness of the intermediate dielectric film layer 2 is t2, and 0.1 μm≤t2≤0.2 μm.

[0040] The material of the top discrete metal layer 3 is gold, silver, aluminum, chromium or platinum; the thickness of the top discrete metal layer 3 is t3 and 0.08 μm≤t3≤0.2 μm.

[0041] The top layer of discrete metal layers 3 includes a plurality of array units, and a periodic array is arranged on the intermediate dielectric film layer 2.

[0042] Each of the array units includes at least one metal disc.

[0043] In some embodiments, the array unit includes one metal disc, as shown in Figure 2 b.

[0044] As shown in Figure 2 , the resonant absorption wavelength in the amplitude modulation characteristic of each metal disc can be roughly calculated as:

[0045] λ r ≈2n eff d(1)

[0046] where n eff is the equivalent refractive index of the structure, and according to formula (1), for a dielectric layer of a non-dispersive material, there is a resonant wavelength that is proportional to the dielectric constant and the diameter of the metal disc.

[0047] At this time, the corresponding simulated absorption spectrum is as shown in Figure 2 a, it can be seen that the super surface with a single metal disc has a bandwidth of 0.49 in the 5-8 μm waveband with an emissivity greater than 0.5, and has a resonant absorption peak at a wavelength of 10.6 μm, thus realizing narrow-band non-atmospheric window heat dissipation and high-efficiency absorption for a 10.6 μm laser wavelength.

[0048] In phase modulation, by optimizing the thickness of the silicon dioxide layer, the phase difference between the reflection of electromagnetic waves in different regions can be adjusted, and when the phase difference is mπ (where m is an odd number), interference cancellation occurs between the reflected waves, thereby reducing the specular reflectivity (zero order) and realizing wide-band laser camouflage. Figure 2 b shows the simulated spectrum of the specular reflectivity of the single-metal-disc super surface in the 0.8-1.6 μm waveband, it can be seen that the reflectivity remains low in this waveband, and the reflectivity at laser wavelengths of 0.905 μm, 1.06 μm, 1.31 μm and 1.55 μm is all kept below 0.25.

[0049] In summary, the super surface with a single metal disc can maintain low reflectivity at multiple commonly used laser wavelengths to realize laser camouflage, maintain low emissivity in the infrared atmospheric window (3-5 μm and 8-14 μm) to realize infrared camouflage, and at the same time, realize narrow-band heat dissipation in the non-atmospheric window.

[0050] In some embodiments, the array unit includes two metal discs, as shown in Figure 3 a.

[0051] In some embodiments, the array unit comprises three metal disks, such as Figure 3 As shown in b.

[0052] In some embodiments, the array unit comprises six metal disks, such as Figure 3 As shown in c.

[0053] from Figure 3 As can be seen from the near-infrared reflection spectrum in AC, increasing the number of metal disks does not affect the low reflection characteristics of the metasurface in the near-infrared band.

[0054] Conversely, such as Figure 3 As shown in d, it can be seen that the metasurface with two metal disks has a bandwidth of 0.69 with an emissivity greater than 0.5 in the 5-8 μm band, and can maintain resonant absorption at a wavelength of 10.6 μm.

[0055] like Figure 3 As shown in Figure e, the metasurface with two metal disks has an emissivity greater than 0.5 in the 5–8 μm band with a bandwidth of 0.84, and can maintain resonant absorption at a wavelength of 10.6 μm.

[0056] like Figure 3 As shown in f, the metasurface with two metal disks has an emissivity greater than 0.5 in the 5–8 μm band with a bandwidth of 1.22, and can maintain resonant absorption at a wavelength of 10.6 μm.

[0057] As the number of metal disks increases, the emissivity bandwidth of the metasurface in the non-atmospheric window gradually increases, while maintaining low emissivity characteristics in the near-infrared band. Broadband heat dissipation in the non-atmospheric window can be achieved by cascading metal disks of different sizes, thereby reducing the thermal instability of the metasurface and achieving higher-performance infrared camouflage.

[0058] The period of each metal disk is fixed. For example, if the period of one metal disk is p1*p1, then the size of two disks is 2p1*p1, the size of three disks is 3p1*p1, the size of four disks is 2p1*2p1, and the size of six disks is 3p1*2p1.

[0059] In some embodiments, such as Figures 4-5As shown, the period of the periodic pattern of the array unit is p, the thickness of the bottom continuous metal film 1 is t1, the thickness of the intermediate dielectric layer 2 is t2, each array unit is a horizontal cascade of metal discs 3-1, 3-2, 3-3, 3-4 of different diameters (d1, d2, d3, and d4), and the thickness of the metal disc is t3. The bottom continuous metal film can achieve total reflection of electromagnetic waves, making the transmittance zero; the intermediate dielectric layer material can adjust the impedance of the device on the one hand, and can construct different transmission phases by adjusting its thickness t2 on the other hand; the top metasurface can excite localized surface plasmon resonance to realize selective absorption of electromagnetic waves, and can also introduce phase difference in the metal region and the non-metal region.

[0060] Exemplarily, as shown in Figure 6 As shown, the period of the periodic pattern of the array unit is p and 6.4 μm≤p≤7.6 μm, the top discrete metal layer 3 contains four metal discs of different diameters; the diameters of the four metal discs are d1, d2, d3, and d4 respectively, and 1.6 μm≤d1≤2.6 μm, 1.6 μm≤d2≤2.6 μm, 1.6 μm≤d3≤2.6 μm, 1.6 μm≤d4≤2.6 μm; the centers of the four metal discs are located at (p / 4, p / 4), (-p / 4, p / 4), (-p / 4, -p / 4), and (p / 4, -p / 4) respectively.

[0061] In combination with the above structure, first, the basic principle of the metasurface in the present application to realize low reflection of incident near-infrared electromagnetic waves is explained as follows:

[0062] The transmission phase realizes the regulation of the phase by the optical path difference in the propagation process of electromagnetic waves. After the electromagnetic wave of wavelength λ is incident, at the position with the metal disc, the electromagnetic wave cannot penetrate and will be directly reflected; and at the position without the metal disc, the electromagnetic wave will continue to propagate through the intermediate dielectric layer until it is reflected by the bottom metal plate. At this time, according to the transmission phase principle, the transmission phase difference is formed between the two reflected waves due to the different propagation optical paths:

[0063]

[0064] Where Δl is the optical path difference between the two electromagnetic waves, which is determined by the propagation path length and the refractive index of the propagation medium:

[0065] Δl = 2(t3 + n d t2) (2)

[0066] For the electromagnetic wave incident in a specific wave band, if the phase difference between the two reflected waves is mπ (where m is an odd number) by optimizing the size of the metal disc and the thickness of the dielectric layer, interference cancellation will occur between the reflected waves, the electromagnetic wave will be scattered to four non-specular directions, so that the energy of the normal direction is greatly reduced, thereby reducing the return energy of the incident electromagnetic wave.

[0067] Next, the implementation principle of the broadband radiation of the super surface in the non-infrared atmospheric window and the low reflection of the far infrared laser in the present application is explained as follows:

[0068] Based on the metal-dielectric layer-metal structure, selective absorption can be achieved by exciting localized surface plasmon resonance with the top layer of discrete metal structures, and the absorption wavelength mainly depends on the size, shape and arrangement period of the top layer of discrete metal structures.

[0069] If the discrete metal structures with different resonance wavelengths are combined in a horizontal cascade manner in the plane, and by adjusting and optimizing the parameters of the discrete metal structures, the connection of multiple resonance peaks in the 5-8 mu m wave band can achieve the effect of broadband absorption.

[0070] According to the Kirchhoff thermal radiation law, the emissivity of an object is equal to the absorptivity, at which time the broadband thermal radiation of the non-atmospheric window can be achieved, and the thermal instability of the structural material can be reduced with high-efficiency heat dissipation performance. In addition, the dielectric constant of the SiO2 material has a dielectric constant mutation in the far infrared wave band, which is introduced as an intermediate dielectric layer material to achieve low reflection of 10.6 mu m wavelength laser.

[0071] In order to better understand the present application, the following further explanation is made in conjunction with Example 1.

[0072] Example 1

[0073] The super surface designed in this embodiment can realize phase control for near-infrared waveband (0.8-1.6 mu m) electromagnetic waves, and reduce the return energy of incident laser including 0.9 mu m, 1.064 mu m, 1.31 mu m and 1.55 mu m by controlling the direction of scattered field.

[0074] Specifically, the bottom layer and the top layer of metal material are selected as gold, and the electromagnetic parameters of the corresponding wave band can be described by Drude model:

[0075]

[0076] Wherein, ω is the frequency of electromagnetic wave, ω p 1886.79 THz is the plasma frequency, and gamma = 14.528 THz is the collision frequency; the intermediate dielectric layer material is SiO2, and its dielectric constant can be obtained from Palik constant table.

[0077] In this embodiment, the metasurface has the following structural parameters: period p = 6.6 μm, bottom metal film thickness t1 = 80 nm, intermediate dielectric layer thickness t2 = 140 nm, and top discrete metal structure consisting of metal disks of different diameters with a thickness t3 = 80 nm.

[0078] Metal disks arranged as follows Figure 6 As shown, the diameters are d1 = 2 μm, d2 = 2.2 μm, d3 = 1.8 μm, and d4 = 2.3 μm, respectively.

[0079] The zero-order (specular) reflectivity of the metasurface in the 0.8–1.6 μm wavelength range is as follows: Figure 7 As shown, the metasurface can maintain a low reflectivity in this wavelength range, with reflectivities of 0.21, 0.06, 0.12, and 0.23 at wavelengths of 0.9 μm, 1.064 μm, 1.31 μm, and 1.55 μm, respectively. Figure 8 The simulation results of three-dimensional far-field scattering of the metasurface at a wavelength of 1.064 μm show that the electromagnetic wave energy reflected by the metasurface is mainly concentrated in four symmetrical non-mirror directions, proving the low reflection echo energy in the mirror direction.

[0080] This example demonstrates amplitude modulation of electromagnetic waves in the mid-infrared and far-infrared bands. Through selective absorption, broadband radiation from the metasurface within the non-atmospheric window and low reflection from far-infrared laser (10.6 μm) are achieved. The selective resonant absorption peaks excited by metal disks of different diameters on the top layer of the metasurface correspond to different wavelengths. By combining four metal disks of different diameters into the same periodic unit, broadband absorption within the non-atmospheric window can be achieved. Simulation results are shown below. Figure 9 As shown. According to Kirchhoff's law of thermal radiation, the infrared emissivity of an object equals its infrared absorptivity. Therefore, the average emissivity of the metasurface in the non-atmospheric window is 0.58, while the average emissivity in the atmospheric window (3–5 μm and 8–14 μm bands) is 0.14 and 0.15, respectively. Compared to the thermal shielding effect caused by the low emissivity across the entire wavelength range, the high emissivity in the non-atmospheric window increases the heat dissipation capability of the metasurface device without affecting its low-emissivity characteristics in the infrared detector window, thus maintaining the low infrared detectability of the metasurface.

[0081] In addition, such as Figure 10 The figure shows the refractive index and extinction coefficient of silicon dioxide in the 3–14 μm wavelength range. It can be seen that silicon dioxide exhibits a sudden change in dielectric constant near the 10.6 μm wavelength. Therefore, using silicon dioxide as an intermediate dielectric layer material can introduce additional resonant absorption peaks.

[0082] Utilizing this feature of the silicon dioxide material, the metasurface can also achieve selective absorption of 10.6 μm electromagnetic waves, thereby reducing the reflection energy of the incident laser at this wavelength. Specifically, the simulation result of the absorption rate at this wavelength is 0.63.

[0083] Therefore, the metasurface can achieve broadband radiation heat management in the mid-infrared non-atmospheric window, infrared low radiation in the atmospheric window, and low reflection of far-infrared laser.

[0084] In addition, in order to illustrate the resonance absorption mechanism, the magnetic field intensity, current density and energy loss intensity distribution at the three resonance wavelengths λ1, λ2 and λ3 and the non-resonance wavelength λ4 are calculated. Figure 11 a shows the magnetic field intensity distribution at the I cross section. At the resonance wavelength λ1 = 5.7 μm, the magnetic field enhancement occurs below the two small-diameter metal discs. In contrast, at the longer resonance wavelength (i.e. λ2 = 6.4 μm), the magnetic field enhancement is observed below the two large-diameter metal discs. These enhancements are due to the wavelength-dependent electric dipole resonance excited by the incident electromagnetic wave, which induces anti-parallel surface currents (as indicated by the arrows in Figure 11 b), resulting in a localized magnetic field. Finally, the energy of the incident light is absorbed in the form of ohmic loss in the metal, as shown by the power loss intensity at the IV cross section in Figure 11 c. The simulated electromagnetic field distribution at the wavelengths λ3 and λ4 is given in Figure 12 .

[0085] Figure 13 a shows the real object picture of the prepared single-layer cascaded metasurface, with an area of 30 x 30 mm 2 , Figure 13 b is the electron microscope picture of the sample. After obtaining the sample, the multispectral camouflage performance of the sample was characterized. The specular and integrated reflectance spectra of the sample in the 0.8-1.6 μm waveband were measured using a spectrophotometer. The results are shown in Figure 13 c, the metasurface maintains a specular reflectance of less than 0.25 in this waveband, while the integrated reflectance is significantly higher than the specular reflectance. The emissivity spectra of the metasurface sample and the control sample in the 3-14 μm waveband were obtained using a Fourier transform infrared spectrometer, and the measurement results are shown in Figure 13 d. The average emissivity of the metasurface sample in the atmospheric window 3-5 μm and 8-14 μm is 0.313 and 0.275, respectively, while in the non-atmospheric window, the average emissivity is 0.51. The infrared camouflage performance of the sample was characterized using a thermal infrared imager. As Figure 13As shown in FIG. e, the sample completely shields the thermal radiation of the human hand, and its radiation temperature is equivalent to the ambient temperature. In order to further study the infrared camouflage performance of the super surface, it is placed on the heating table together with the control sample and glass for characterization of thermal infrared radiation characteristics. The average radiation rate of the control sample in the 5-14 μm band is 0.312 Figure 13 As shown in FIG. e, the sample completely shields the thermal radiation of the human hand, and its radiation temperature is equivalent to the ambient temperature. In order to further study the infrared camouflage performance of the super surface, it is placed on the heating table together with the control sample and glass for characterization of thermal infrared radiation characteristics. The average radiation rate of the control sample in the 5-14 μm band is 0.312 Figure 13 As shown in FIG. e, the sample completely shields the thermal radiation of the human hand, and its radiation temperature is equivalent to the ambient temperature. In order to further study the infrared camouflage performance of the super surface, it is placed on the heating table together with the control sample and glass for characterization of thermal infrared radiation characteristics. The average radiation rate of the control sample in the 5-14 μm band is 0.312

[0086] In order to further illustrate the broadband radiation heat dissipation capability of the super surface, the surface temperature and radiation temperature of the super surface and the control sample are measured when heated at different input powers. The experimental results are shown in FIG. Figure 13 As shown in FIG. e, the sample completely shields the thermal radiation of the human hand, and its radiation temperature is equivalent to the ambient temperature. In order to further study the infrared camouflage performance of the super surface, it is placed on the heating table together with the control sample and glass for characterization of thermal infrared radiation characteristics. The average radiation rate of the control sample in the 5-14 μm band is 0.312 2 When the input power is 14.1 W (corresponding to a power density of 1.57 W / cm Figure 13 h provides thermal infrared images of the super surface and the control sample at different heating powers, which intuitively shows the infrared camouflage effect of the super surface. Therefore, the broadband high radiation rate characteristics in the 5-8 μm band can reduce the surface temperature of the super surface through the non-atmospheric window, thereby further enhancing its infrared camouflage performance.

[0087] The technical features of the above embodiments can be combined in any way. In order to make the description concise, not all possible combinations of the technical features in the above embodiments are described, but as long as the combinations of the technical features do not exist, they should be considered as the scope of the description.

[0088] The above-described embodiments only express several embodiments of the present application, and the description is more specific and detailed, but it should not be understood as limiting the scope of the patent of the present application. It should be noted that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A single-layer metasurface structure for simultaneously realizing low reflection of near-infrared and far-infrared laser, low infrared radiation and heat management, characterized in that: the single-layer metasurface structure comprises a bottom continuous metal film (1), an intermediate dielectric film layer (2) and a top discrete metal layer (3); the bottom continuous metal film layer (1) is used to realize total reflection of electromagnetic waves so that the transmittance is zero; the intermediate dielectric film layer (2) is used to introduce resonant absorption at a wavelength of 10.6 μm and control the phase of the incident electromagnetic wave reflected by the bottom continuous metal film (1) by adjusting the thickness thereof; the top discrete metal layer (3) is arranged on the intermediate dielectric film layer (2) and is used to form a reflection phase difference between the metal region and the non-metal region to realize regulation of the near-infrared electromagnetic wave scattering field wavefront and is also used to introduce localized surface plasmon resonance to realize infrared selective absorption; the top discrete metal layer (3) comprises a plurality of array units and is arranged in a periodic array on the intermediate dielectric film layer (2); each array unit comprises at least one metal disc. ​ ​ ​ ​ 2. The single-layer metasurface structure of claim 1, wherein: The material of the bottom continuous metal film (1) is gold, silver, aluminum, chromium or platinum; the thickness of the bottom continuous metal film (1) is t 1 and t 1≥80nm.

3. The single-layer metasurface structure of claim 1 or 2, wherein: The intermediate dielectric film layer (2) is a silicon dioxide material; the thickness of the intermediate dielectric film layer (2) is t 2, and 0.1 μm≤ t 2≤0.2 μm.

4. The single-layer metasurface structure of claim 3, wherein: The material of the top layer discrete metal layer (3) is gold, silver, aluminum, chromium or platinum; the thickness of the top layer discrete metal layer (3) is t 3 and 0.08 μm ≤ t 3 ≤ 0.2 μm.

5. The single-layer metasurface structure of claim 4, wherein: ​ 6. The single-layer metasurface structure of claim 5, wherein: ​ 7. The single-layer metasurface structure of claim 6, wherein: The period of the periodic pattern of the array units is p and 6.4 μm ≤ p ≤ 7.6 μm, each of the array units comprising four metal discs of different diameters; the diameters of the four metal discs are d 1, d 2, d 3 and d 4, and 1.6 μm ≤ d 1≤ 2.6 μm, 1.6 μm ≤ d 2≤ 2.6 μm, 1.6 μm ≤ d 3≤ 2.6 μm, 1.6 μm ≤ d 4≤ 2.6 μm; the centers of the four metal discs are located at p 1 / 4, p 1 / 4), (- p 1 / 4, p 1 / 4), (- p 1 / 4, p 1 / 4), (- p 1 / 4, p 1 / 4).

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