A multilayer film compatible with H, K, middle wave infrared and long wave infrared wave band stealth and radiation heat dissipation

Abstract

The application discloses a multilayer film compatible with H, K, medium-wave infrared and long-wave infrared wave band stealth and radiation heat dissipation. The multilayer film comprises a substrate, a metal reflection layer, a photonic crystal layer fusing loss medium and an H and K wave band anti-reflection layer, the absorptivity of the H and K wave band is greater than 0.5, the emissivity of the medium-wave infrared and long-wave infrared wave band is lower than 0.5, and the emissivity of the very long-wave infrared wave band is greater than 0.5; the photonic crystal layer fusing loss medium is a multilayer structure and is formed by alternately stacking medium layers of multiple high and low refractive index medium materials. The multilayer film can realize the stealth of solar radiation and thermal radiation and has effective radiation heat dissipation heat management capability at the same time, and can be widely applied to the fields of aviation, spaceflight and the like.

Description

Technical Field

[0001] This invention belongs to the field of multi-band stealth technology, specifically relating to a multi-layer thin film that is compatible with H, K, mid-wave infrared and long-wave infrared bands for stealth and radiative heat dissipation. Background Technology

[0002] The rapid development of infrared detection technology has brought significant challenges to the stealth and survivability of aerospace vehicles. Researching multi-band compatible infrared stealth methods and materials, considering the sources of infrared signals in various bands and the characteristics of infrared detection equipment, is crucial for improving the infrared stealth and survivability of aerospace vehicles. Simultaneously, considering the thin atmosphere and intense solar radiation in environments such as high altitudes, near-space, and outer space, it is essential to rationally control the infrared radiation performance of aerospace vehicles to maintain them within a safe temperature range.

[0003] For aerospace vehicles, infrared detection equipment in the H, K, mid-infrared, and long-infrared bands poses a particularly significant threat. These bands have weak background radiation and high atmospheric transmittance, resulting in a high signal-to-noise ratio for aerospace vehicles, making them easier to detect. In the H (1.5–1.8 μm) and K (2–2.4 μm) bands, the signal source is primarily reflected solar radiation; therefore, increasing the absorption of the target surface (i.e., reducing reflected signals) is necessary to enhance stealth. In the mid-infrared (3–5 μm) and long-infrared (8–14 μm) bands, the signal source is primarily the target's own thermal radiation; therefore, suppressing radiation signals is crucial for stealth. Corresponding methods include reducing the target surface temperature and emissivity.

[0004] During operation, aerospace vehicles experience temperature increases due to the absorption of solar radiation and the heat generated by their own equipment. To maintain these internal and external components within a safe operating temperature range, their thermal control systems must be rationally designed to dissipate waste heat. In environments such as high altitudes, near-space, and outer space, the thin atmosphere severely limits conduction and convection heat dissipation, making radiation heat dissipation almost the only effective means of cooling. Therefore, thermal management capabilities are primarily achieved through radiation heat dissipation via non-atmospheric transparent windows (i.e., non-infrared detection bands).

[0005] Existing multi-band stealth technologies compatible with radiative heat dissipation mainly target mid-infrared and long-infrared detection equipment for stealth, and utilize the mid-to-long-infrared (5-8 μm) band for radiative heat dissipation. Examples include wavelength-selective emitters with thermal control management, infrared selective emitters and their applications (CN116107002A), a spectrally selective low-emissivity infrared stealth coating and its preparation method and application (CN116430498B), and an infrared stealth and radiative heat dissipation thin film based on Ge2Sb2Te5 and its preparation method (CN115747740A).

[0006] The shortcomings of the existing technology are: (1) it is not compatible with H and K band stealth and cannot hide the solar radiation signals reflected by the target; (2) the heat dissipation efficiency in the mid- and long-wave infrared band is low (the maximum heat dissipation power density is 58W / m at 300K). 2 It does not utilize the very long-wave infrared band, which has a higher heat dissipation efficiency (maximum heat dissipation power density of 171 W / m² at 300 K). 2 (3) There are problems such as a large number of thin film layers, large thickness, and complex preparation process.

[0007] In summary, existing multi-band stealth technologies cannot simultaneously cover the highly threatening infrared detection bands such as H, K, mid-infrared, and long-infrared, and fully utilize non-atmospheric transparent windows for radiative heat dissipation. Therefore, how to design a stealth material that is easy to fabricate and can achieve both infrared stealth in the H, K, mid-infrared, and long-infrared bands and radiative heat dissipation is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0008] To address the problems existing in the prior art, the present invention provides a multilayer thin film that is compatible with stealth and radiative heat dissipation in the H, K, mid-wave infrared and long-wave infrared bands. This thin film can achieve stealth in the H, K, mid-wave infrared and long-wave infrared bands, and is compatible with radiative heat dissipation in the very long-wave infrared band.

[0009] The multilayer thin film of the present invention can achieve both stealth from solar radiation and thermal radiation and effective radiative heat dissipation thermal management capabilities, and can be widely used in aviation, aerospace and other fields.

[0010] The technical solution adopted in this invention is as follows:

[0011] This invention comprises, sequentially arranged from the inside out or from the bottom up, a metal reflective layer, a photonic crystal layer with a fused loss medium, and an H- and K-band antireflection layers; satisfying the following:

[0012] The infrared absorption rate in the 1.5-1.8μm and 2-2.4μm bands is higher than 0.5;

[0013] The infrared emissivity in the 3-5μm and 8-13μm bands is less than 0.5;

[0014] The infrared emissivity in the 13-25μm band is higher than 0.5.

[0015] In the above multilayer thin film structure, the metal reflective layer is used to achieve low emissivity in the mid-wave infrared (3-5μm) and long-wave infrared (8-13μm) bands; the photonic crystal layer with fused loss medium is used to achieve high absorption in the H (1.5-1.8μm) and K (1.4-2.5μm) bands and high emissivity in the very long-wave infrared (13-25μm) band, while maintaining low emissivity in the mid-wave infrared (3-5μm) and long-wave infrared (8-13μm) bands; and the H and K band antireflection layers are used to improve the absorption in the H (1.5-1.8μm) and K (1.4-2.5μm) bands.

[0016] Preferably, the metal reflective layer is one of platinum, chromium, nickel, tungsten, molybdenum, etc., and more preferably nickel.

[0017] Preferably, the thickness of the metal reflective layer is greater than 10 nm. More preferably, the thickness of the metal reflective layer is 90–150 nm.

[0018] The photonic crystal layer of the fusion loss medium has a multi-layer structure, which is composed of multiple high and low refractive index medium layers stacked alternately from the inside out or from the bottom up.

[0019] Each layer is made of either a high-refractive-index medium or a low-refractive-index medium. Between adjacent high-refractive-index medium layers, there is a low-refractive-index medium layer, and between adjacent low-refractive-index medium layers, there is a high-refractive-index medium layer.

[0020] In the photonic crystal layer of the fused loss medium, the high refractive index medium material is selected from one or more of germanium, silicon, tellurium, germanium-antimony-tellurium alloy, germanium-antimony-selenium alloy, and germanium-antimony-selenium-tellurium alloy, and more preferably germanium and germanium-antimony-tellurium alloy. The low refractive index medium material is selected from one or more of magnesium fluoride, ytterbium fluoride, calcium fluoride, barium fluoride, silicon dioxide, aluminum oxide, hafnium oxide, zinc oxide, zinc sulfide, and zinc selenide.

[0021] Furthermore, fluorides include, but are not limited to, magnesium fluoride, ytterbium fluoride, calcium fluoride, and barium fluoride. Furthermore, oxides include, but are not limited to, silicon dioxide, aluminum oxide, hafnium oxide, and zinc oxide. Furthermore, sulfides include, but are not limited to, zinc sulfide.

[0022] As a further preferred option, the low refractive index material is hafnium oxide (or zinc oxide).

[0023] As a further preferred embodiment, in the photonic crystal layer of the fused loss medium, the thickness of each layer of the high refractive index medium material is 100-800 nm, and the thickness of each layer of the low refractive index medium material is 1000-2500 nm.

[0024] In the photonic crystal layer of the fused loss medium, the high refractive index medium material / low refractive index medium material includes one or more materials that are loss mediums in the infrared band of H, K or very long wavelengths, and the loss medium material refers to a material whose imaginary part of negative refractive index is not zero.

[0025] In the photonic crystal layer of the fused loss medium, the material of the loss medium is selected from one or more of germanium, tellurium, germanium-antimony-tellurium alloy, germanium-antimony-selenium alloy, germanium-antimony-selenium-tellurium alloy, magnesium fluoride, silicon dioxide, aluminum oxide, hafnium oxide, and zinc oxide.

[0026] As a further preferred embodiment, the photonic crystal layer of the fused loss medium is composed of four layers of dielectric materials with three different refractive indices stacked alternately.

[0027] In this technical solution, the photonic crystal layer with fused loss medium is composed of alternating layers of high and low refractive index dielectric materials, and there can be two types of high refractive index or low refractive index materials; taking two types of high refractive index materials as an example, the high refractive index dielectric material layers that are alternately stacked with low refractive index dielectric material layers are made of two different types of materials with different refractive indices.

[0028] Furthermore, the three dielectric materials with different refractive indices are germanium, germanium-antimony-tellurium alloy, and hafnium oxide. The photonic crystal layer consists of a hafnium oxide layer, a germanium layer, a hafnium oxide layer, and a germanium-antimony-tellurium alloy layer from bottom to top. The thickness of the germanium layer is 300-800 nm; the thickness of the germanium-antimony-tellurium alloy layer is 100-300 nm; and there are two hafnium oxide (or zinc oxide) layers with a thickness of 1000-2500 nm.

[0029] Preferably, the total number of dielectric layers in the photonic crystal layer of the fused loss medium is 4 to 8.

[0030] The antireflective layer for the H and K bands is made of one or more of the following: magnesium fluoride, ytterbium fluoride, calcium fluoride, barium fluoride, silicon dioxide, aluminum oxide, hafnium oxide, zinc oxide, zinc sulfide, and zinc selenide, with zinc sulfide being more preferred. The thickness of the antireflective layer for the H and K bands is 100–400 nm, more preferably 150–300 nm.

[0031] Preferably, the multilayer film further includes a substrate for mechanical support.

[0032] As a further preferred embodiment, the substrate material is a solid or flexible material, including but not limited to one or more of silicon, silicon dioxide, polyimide (PI), polyethylene (PE), and polyetherimide (PEI). Silicon is even more preferred.

[0033] As a further preferred option, the thickness of the substrate can be set according to actual needs.

[0034] The multilayer thin film of this invention achieves stealth in the H, K, mid-infrared, and long-infrared bands, requiring the following conditions: high absorptivity (i.e., low reflectivity) in the 1.5-1.8 μm H band and 2-2.4 μm K band to reduce reflected solar radiation. Low emissivity in the 3-5 μm mid-infrared band and 8-13 μm long-infrared band to suppress its own thermal radiation. High emissivity in the 13-25 μm very long-infrared band to achieve radiative heat dissipation. The multilayer thin film of this invention achieves high absorptivity in the H and K bands and low emissivity in the mid-infrared and long-infrared bands, thus achieving stealth; it also achieves radiative heat dissipation in the very long-infrared band. The fabrication process is simple and can meet the requirements of infrared multi-band stealth and thermal management in applications such as space.

[0035] This invention relates to a multilayer thin film compatible with stealth and radiative heat dissipation in the H, K, mid-infrared, and long-infrared bands. It comprises a substrate, a metallic reflective layer, a photonic crystal layer with a fused loss dielectric, and an H and K band antireflection layer. The film satisfies the following requirements: an absorptivity greater than 0.5 in the H and K bands, an emissivity less than 0.5 in the mid-infrared and long-infrared bands, and an emissivity greater than 0.5 in the very long-infrared band. This multilayer thin film achieves stealth capabilities in the H, K, mid-infrared, and long-infrared bands while also possessing effective radiative heat dissipation thermal management capabilities, making it widely applicable in aerospace and other fields.

[0036] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0037] This invention relates to a multilayer thin film compatible with H, K, mid-infrared, and long-infrared bands for stealth and radiative heat dissipation. It can reduce reflected signals from solar radiation in the H and K bands, providing resistance against passive H and K band infrared observation equipment. It can also significantly reduce thermal radiation signals in the mid-infrared and long-infrared bands, exhibiting strong resistance to thermal detectors. Furthermore, this multilayer thin film can achieve radiative heat dissipation in the very long-infrared band, providing effective thermal management in extreme environments such as space, ensuring aerospace vehicles remain within a safe temperature range. It can be widely applied in aviation, aerospace, and other fields. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the structure of the multilayer thin film in Embodiment 1 of the present invention;

[0039] Figure 2 The above are the simulated and experimental absorption / emissivity spectra of the multilayer thin film in Example 1 of this invention;

[0040] Figure 3 Images of the multilayer thin film in Embodiment 1 of the present invention in the H, K, mid-wave infrared and long-wave infrared bands in a simulated application scenario;

[0041] Figure 4 This is a comparison diagram of the equilibrium temperature of the multilayer thin film in Embodiment 1 of the present invention under different input heat power densities and that of a traditional infrared stealth material (nickel film);

[0042] Figure 5 This is a schematic diagram of the structure of the multilayer thin film in Embodiment 2 of the present invention;

[0043] Figure 6 This is a simulated absorption / emissivity spectrum of the multilayer thin film in Example 2 of the present invention;

[0044] Figure 7 This is a schematic diagram of the structure of the multilayer thin film in Comparative Example 1 of the present invention;

[0045] Figure 8 The simulated absorption / emissivity spectrum of the multilayer thin film in Comparative Example 1 of this invention is shown.

[0046] Figure 9 This is a schematic diagram of the structure of the multilayer thin film in Comparative Example 2 of the present invention;

[0047] Figure 10 This is a simulated absorption / emissivity spectrum of the multilayer thin film in Comparative Example 2 of this invention.

[0048] Table 1 shows the average absorption / emissivity of each band in the examples and comparative examples. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the technical solutions of this invention and are not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0050] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0051] This invention provides a multilayer thin film compatible with stealth and radiative heat dissipation in the H, K, mid-wave infrared and long-wave infrared bands, comprising: a substrate, a metal reflective layer sequentially disposed on the surface of the substrate, a photonic crystal layer with fused loss medium, and an H and K band antireflection layer;

[0052] The substrate layer, serving as a mechanical support, can have its thickness adjusted as needed. Specifically, the substrate material can be a solid or flexible material. Preferably, the substrate material is silicon.

[0053] A metallic reflective layer is used to achieve low emissivity in the mid-infrared (3-5 μm) and long-infrared (8-13 μm) bands. Specifically, the metallic reflective layer is a thin metal film with a thickness greater than the infrared skin depth. Preferably, the material of the metallic reflective layer is nickel, and the thickness is greater than 10 nm.

[0054] A photonic crystal layer incorporating a lossy dielectric is used to achieve high absorptivity in the H (1.5-1.8 μm) and K (1.4-2.5 μm) bands and high emissivity in the very long infrared (13-25 μm) band, while maintaining low emissivity in the mid-infrared (3-5 μm) and long infrared (8-13 μm) bands. Specifically, the photonic crystal layer incorporating the lossy dielectric is a multilayer structure composed of alternating layers of dielectric materials with different refractive indices, wherein one or more of these materials are lossy dielectric materials in the H, K, or very long infrared bands. Preferably, the photonic crystal layer incorporating the lossy dielectric is a multilayer structure composed of alternating layers of dielectric materials with three different refractive indices, including one lossy dielectric material for the H, K, and very long infrared bands, and one lossy dielectric material for the very long infrared band. Preferably, the three dielectric materials are germanium, germanium-antimony-tellurium alloy, and hafnium oxide (or zinc oxide), wherein the germanium-antimony-tellurium alloy is the loss dielectric material for the H, K and very long-wave infrared bands, and the hafnium oxide (or zinc oxide) is the loss dielectric material for the very long-wave infrared band; the thickness of the germanium layer is 300-800 nm, the thickness of the germanium-antimony-tellurium alloy layer is 100-300 nm, and the thickness of the hafnium oxide (or zinc oxide) layer is 1000-2500 nm.

[0055] H- and K-band antireflective layers are used to improve the absorption rate in the H (1.5-1.8 μm) and K (1.4-2.5 μm) bands; specifically, the H- and K-band antireflective layer material is a dielectric material. Preferably, the dielectric material is zinc sulfide; the zinc sulfide layer thickness is 100-400 nm.

[0056] The present invention will be further illustrated below with reference to specific embodiments.

[0057] The embodiments of the present invention are as follows:

[0058] Example 1

[0059] like Figure 1 As shown, a multilayer thin film compatible with H, K, mid-wave infrared and long-wave infrared bands for stealth and radiative heat dissipation includes a substrate, a metal reflective layer, a photonic crystal layer with fused loss medium and an H and K band antireflection layer arranged sequentially from bottom to top (or from inside to outside).

[0060] The substrate material is silicon; the metal reflective layer is a 120nm thick nickel layer; the photonic crystal layer with fused loss medium has a four-layer structure, consisting of a 1220nm thick hafnium oxide layer, a 600nm thick germanium layer, a 1930nm thick hafnium oxide layer, and a 165nm thick germanium-antimony-tellurium alloy layer from bottom to top; and the H and K band antireflection layer is a 215nm thick zinc sulfide layer.

[0061] The absorption / emissivity spectra of the aforementioned multilayer thin films compatible with H, K, mid-infrared, and long-infrared bands for stealth and radiative heat dissipation are as follows: Figure 2 As shown. By Figure 2 As can be seen, the aforementioned multilayer thin films achieve absorption-based stealth in the H and K bands, low emissivity stealth in the mid-infrared and long-infrared bands, and high emissivity heat dissipation in the very long-infrared band. Specifically, the average absorptivity is 0.839 in the 1.5-1.8 μm H band and 0.633 in the 2-2.4 μm K band. The average emissivity is 0.132 in the 3-5 μm mid-infrared band, 0.142 in the 8-13 μm long-infrared band, and 0.798 in the 13-25 μm very long-infrared band.

[0062] The infrared stealth capability of the multilayer thin film in this embodiment is demonstrated as follows: Figure 3 As shown, a multilayer thin film sample was adhered to the surface of a satellite model and placed outdoors in a clear, open environment. The satellite model was photographed using cameras in the H, K, mid-wave infrared, and long-wave infrared bands. In the H and K bands, compared to the location of the strongest infrared signal on the satellite model surface, the signal intensity of the multilayer thin film in this embodiment decreased by 36.9% and 24.2%, respectively. In the mid-wave infrared and long-wave infrared bands, compared to the location of the strongest thermal radiation signal on the satellite model surface, the radiation temperature of the multilayer thin film in this embodiment decreased by 11.7°C and 24.5°C, respectively.

[0063] The radiative heat dissipation capability of the multilayer thin film in this embodiment is demonstrated as follows: Figure 4 As shown. The macroscopic shape of the multilayer thin film sample is a quarter-inch 4-inch disk, and the selected conventional infrared stealth material is a nickel film (120 nm thick) of the same macroscopic shape. The heating device is an electric heating element connected to a DC power source and placed on a heat-insulating nylon column, and the temperature measuring device is a thermocouple in contact with the sample or nickel film surface. The multilayer thin film sample or nickel film, the heating device, and the temperature measuring device are all placed in a vacuum chamber. The vacuum level in the vacuum chamber is 0.15 Pa, and the cold source is liquid nitrogen.

[0064] The heating power was set from low to high, and the surface temperatures of the multilayer thin film sample and the nickel film in this embodiment when they reached thermal equilibrium were recorded respectively. The results are as follows: Figure 4As shown. Under the same heating power, the temperature of the multilayer thin film sample proposed in this invention is lower than that of conventional low-emissivity surface materials. For example, when the input heat power density is 1200 W / m², 2 At that time, the actual surface temperature of the sample (81.3℃) was 39.8℃ lower than that of the nickel film (121.1℃). At high temperatures, the designed structure exhibits superior radiative heat dissipation thermal management characteristics.

[0065] Example 2

[0066] like Figure 5 As shown, a multilayer thin film compatible with H, K, mid-wave infrared and long-wave infrared bands for stealth and radiative heat dissipation includes a substrate, a metal reflective layer, a photonic crystal layer with fused loss medium and an H and K band antireflection layer arranged sequentially from bottom to top (or from inside to outside).

[0067] The substrate material is silicon; the metal reflective layer is a 120nm thick nickel layer; the photonic crystal layer with fused loss medium has a four-layer structure, consisting of a 1690nm thick zinc oxide layer, a 460nm thick germanium layer, a 2350nm thick zinc oxide layer, and a 151nm thick germanium-antimony-tellurium alloy layer from bottom to top; and the H and K band antireflection layer is a 215nm thick zinc sulfide layer.

[0068] The absorption / emissivity spectra of the aforementioned multilayer thin films compatible with H, K, mid-infrared, and long-infrared bands for stealth and radiative heat dissipation are as follows: Figure 6 As shown. By Figure 6 As can be seen, the aforementioned multilayer thin films achieve absorption-based stealth in the H and K bands, low emissivity stealth in the mid-infrared and long-infrared bands, and high emissivity heat dissipation in the very long-infrared band. Specifically, the average absorptivity is 0.815 in the 1.5-1.8 μm H band and 0.884 in the 2-2.4 μm K band. The average emissivity is 0.324 in the 3-5 μm mid-infrared band, 0.194 in the 8-13 μm long-infrared band, and 0.665 in the 13-25 μm very long-infrared band.

[0069] Comparative Example 1

[0070] like Figure 7 As shown, a multilayer thin film without H and K band antireflection layers includes a substrate, a metal reflective layer, and a photonic crystal layer of fusion loss medium arranged sequentially from bottom to top (or from inside to outside).

[0071] The substrate material is silicon; the metal reflective layer is a 120nm thick nickel layer; the photonic crystal layer with fused loss medium has a four-layer structure, consisting of a 1220nm thick hafnium oxide layer, a 600nm thick germanium layer, a 1930nm thick hafnium oxide layer, and a 165nm thick germanium-antimony-tellurium alloy layer from bottom to top.

[0072] The absorption / emissivity spectra of the above-mentioned multilayer thin films excluding H and K band antireflection layers are as follows: Figure 8 As shown, the average absorptivity is 0.384 in the H-band (1.5-1.8 μm) and 0.605 in the K-band (2-2.4 μm). The average emissivity is 0.162 in the mid-infrared band (3-5 μm), 0.203 in the long-infrared band (8-13 μm), and 0.791 in the very long-infrared band (13-25 μm). The comparative multilayer thin films exhibit low absorptivity in the H-band, making H-band stealth impossible.

[0073] Comparative Example 2

[0074] like Figure 9 As shown, a multilayer thin film of a photonic crystal layer material that does not contain a lossy dielectric material includes a substrate, a metal reflective layer, a lossless dielectric photonic crystal layer and an H and K band antireflection layer arranged sequentially from bottom to top (or from inside to outside);

[0075] The substrate material is silicon; the metal reflective layer is a 120nm thick nickel layer; the lossless photonic crystal layer has a four-layer structure, consisting of a 1020nm thick zinc sulfide layer, a 460nm thick germanium layer, a 1540nm thick zinc sulfide layer, and a 230nm thick germanium layer from bottom to top; and the H and K band antireflection layer is a 215nm thick zinc sulfide layer.

[0076] The absorption / emissivity spectra of the above-mentioned photonic crystal layer materials that do not contain lossy dielectric materials are as follows: Figure 10 As shown, the average absorptivity is 0.575 in the H-band (1.5-1.8 μm) and 0.322 in the K-band (2-2.4 μm). The average emissivity is 0.207 in the mid-infrared band (3-5 μm), 0.028 in the long-infrared band (8-13 μm), and 0.107 in the very long-infrared band (13-25 μm). The comparative multilayer thin film exhibits low absorptivity in the K-band, making K-band stealth impossible; simultaneously, its low emissivity in the very long-infrared band prevents radiative heat dissipation.

[0077] The average absorption / emissivity of the examples and comparative examples in various infrared bands is shown in Table 1.

[0078] Table 1. Average Absorbance / Emissivity of Each Band in Examples and Comparative Examples

[0079] Absorption / emissivity H K MWIR LWIR VLWIR Example 1 0.839 0.633 0.132 0.142 0.798 Example 2 0.815 0.884 0.324 0.194 0.665 Comparative Example 1 0.384 0.605 0.162 0.203 0.791 Comparative Example 2 0.575 0.322 0.207 0.028 0.107

[0080] All embodiments achieved the spectral requirements for stealth and radiative heat dissipation compatible with H, K, mid-infrared, and long-infrared bands. Comparative Example 1, lacking H and K band antireflection layers, exhibits low absorptivity in the H band, thus failing to achieve H-band stealth. This comparative example illustrates the importance of H and K band antireflection layers for achieving H-band compatible stealth. Comparative Example 2, with its photonic crystal layer material lacking lossy dielectric material, exhibits low absorptivity in the K band and low emissivity in the very long-infrared band, failing to achieve K-band stealth and radiative heat dissipation. This comparative example illustrates the importance of a photonic crystal layer incorporating lossy dielectric for achieving K-band compatible stealth and radiative heat dissipation.

[0081] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A multilayer thin film compatible with stealth and radiative heat dissipation in the H, K, mid-wave infrared and long-wave infrared bands, characterized in that: It includes a metal reflective layer, a photonic crystal layer with a fusion loss medium, and H and K band antireflection layers arranged sequentially from the inside out or from the bottom up; it satisfies: The infrared absorption rate in the 1.5-1.8μm and 2-2.4μm bands is higher than 0.5; The infrared emissivity in the 3-5μm and 8-13μm bands is less than 0.5; The infrared emissivity in the 13-25μm band is higher than 0.5; The photonic crystal layer of the fusion loss medium is composed of four layers of dielectric materials with three different refractive indices stacked alternately. The three dielectric materials with different refractive indices are germanium, germanium-antimony-tellurium alloy and hafnium oxide. The photonic crystal layer consists of a hafnium oxide layer, a germanium layer, a hafnium oxide layer and a germanium-antimony-tellurium alloy layer from bottom to top. The thickness of the germanium layer is 300-800 nm; the thickness of the germanium-antimony-tellurium alloy layer is 100-300 nm; there are two hafnium oxide layers, and each layer is 1000-2500 nm thick.

2. The multilayer thin film compatible with H, K, mid-wave infrared and long-wave infrared bands for stealth and radiative heat dissipation according to claim 1, characterized in that: The metal reflective layer is one of platinum, chromium, nickel, tungsten, and molybdenum, and the thickness of the metal reflective layer is greater than 10 nm.

3. The multilayer thin film compatible with H, K, mid-wave infrared and long-wave infrared bands for stealth and radiative heat dissipation according to claim 1, characterized in that: The photonic crystal layer of the fusion loss medium has a multi-layer structure, which is composed of alternating layers of various high and low refractive index medium materials. Each layer is made of either a high-refractive-index medium or a low-refractive-index medium. Between adjacent high-refractive-index medium layers, there is a low-refractive-index medium layer, and between adjacent low-refractive-index medium layers, there is a high-refractive-index medium layer.

4. The multilayer thin film compatible with H, K, mid-wave infrared and long-wave infrared bands for stealth and radiative heat dissipation according to claim 3, characterized in that: In the photonic crystal layer of the fused loss medium, the high refractive index medium material is selected from one or more of germanium, silicon, tellurium, germanium-antimony-tellurium alloy, germanium-antimony-selenium alloy, and germanium-antimony-selenium-tellurium alloy. The low refractive index medium material is selected from one or more of magnesium fluoride, ytterbium fluoride, calcium fluoride, barium fluoride, silicon dioxide, aluminum oxide, hafnium oxide, zinc oxide, zinc sulfide, and zinc selenide.

5. The multilayer thin film compatible with H, K, mid-wave infrared and long-wave infrared bands for stealth and radiative heat dissipation according to claim 3, characterized in that: In the photonic crystal layer of the fused loss medium, the thickness of each layer of the high refractive index medium material is 100~800nm, and the thickness of each layer of the low refractive index medium material is 1000~2500nm.

6. The multilayer thin film compatible with H, K, mid-wave infrared and long-wave infrared bands for stealth and radiative heat dissipation according to claim 3, characterized in that: In the photonic crystal layer of the fused loss medium, the high refractive index medium material / low refractive index medium material includes one or more materials that are loss mediums in the infrared band of H, K or very long wavelengths.

7. The multilayer thin film compatible with H, K, mid-wave infrared and long-wave infrared bands for stealth and radiative heat dissipation according to claim 6, characterized in that: In the photonic crystal layer of the fused loss medium, the material of the loss medium is selected from one or more of germanium, tellurium, germanium-antimony-tellurium alloy, germanium-antimony-selenium alloy, germanium-antimony-selenium-tellurium alloy, magnesium fluoride, silicon dioxide, aluminum oxide, hafnium oxide, and zinc oxide.

8. The multilayer thin film compatible with H, K, mid-wave infrared and long-wave infrared bands for stealth and radiative heat dissipation according to claim 1, characterized in that: The total number of dielectric layers in the photonic crystal layer of the fused loss medium is 4 to 8.

9. The multilayer thin film compatible with H, K, mid-wave infrared and long-wave infrared bands for stealth and radiative heat dissipation according to claim 1, characterized in that: The material of the H and K band antireflection layer is one or more of magnesium fluoride, ytterbium fluoride, calcium fluoride, barium fluoride, silicon dioxide, aluminum oxide, hafnium oxide, zinc oxide, zinc sulfide, and zinc selenide, and the thickness of the H and K band antireflection layer is 100~400nm.

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