Multi-layer film compatible with H, K, medium-wave infrared and long-wave infrared band stealth and radiation heat dissipation

Abstract

The invention discloses a multilayer film compatible with H, K, medium-wave infrared and long-wave infrared band stealth and radiation heat dissipation. Comprising a substrate, a metal reflection layer, a photonic crystal layer fused with a loss medium and an H and K wave band antireflection layer, the absorption rate of H and K wave bands is larger than 0.5, the emissivity of medium wave infrared and long wave infrared bands is lower than 0.5, and the emissivity of very long wave infrared bands is larger than 0.5; the photonic crystal layer fused with the loss medium is of a multi-layer structure and is formed by alternately stacking dielectric layers made of various high-refractive-index dielectric materials and dielectric layers made of various low-refractive-index dielectric materials. The multilayer film provided by the invention has effective radiation heat dissipation and heat management capabilities while realizing stealth on solar radiation and heat radiation, and can be widely applied to the fields of aviation, aerospace and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of multi-band stealth, and in particular relates to a multi-layer film that is compatible with H, K, mid-wave infrared and long-wave infrared band stealth and radiation heat dissipation. Background Art

[0002] The rapid development of infrared detection technology has brought great challenges to the concealment and survival of aerospace vehicles. According to the sources of infrared signals in various bands and the characteristics of infrared detection equipment, it is of great significance to study infrared stealth methods and materials compatible with multiple bands to improve the infrared stealth capability and survivability of aerospace vehicles. At the same time, considering the thin atmosphere and strong solar radiation in high altitude, near space, outer space and other environments, the infrared radiation performance of aerospace vehicles must be reasonably regulated to keep it within a safe temperature range.

[0003] For aerospace vehicles, the threat posed by infrared detection equipment in the H, K, medium-wave infrared, and long-wave infrared bands is particularly great. The sky background radiation in these bands is weak and the atmospheric transmittance is high, which makes aerospace vehicles have a higher signal-to-noise ratio for infrared detection equipment and easier to detect. In the H (1.5-1.8 μm) and K (2-2.4 μm) bands, the signal source is mainly reflected solar radiation, and the absorption of the target surface must be increased (i.e., the reflected signal must be reduced) to enhance its concealment. In the medium-wave infrared (3-5 μm) and long-wave infrared (8-14 μm) bands, the signal source is mainly the thermal radiation of the target itself, and the stealth effect must be achieved by suppressing the radiation signal; the corresponding means mainly include reducing the temperature of the target surface and reducing the emissivity of the target surface.

[0004] During the operation of aerospace vehicles, the temperature will rise due to the absorption of solar radiation energy and the heat generated by their own equipment. In order to maintain the internal and external equipment within a safe operating temperature range, the thermal control system must be reasonably designed to dissipate waste heat outward. Due to the thin atmosphere in high altitude, near space, outer space and other environments, conduction and convection heat dissipation methods are greatly limited, and radiation heat dissipation has become almost the only effective heat dissipation method. Therefore, thermal management capabilities are mainly achieved through radiation heat dissipation of non-atmospheric transparent windows (that is, non-infrared detection bands).

[0005] The existing multi-band stealth technology compatible with radiation heat dissipation is mainly used for stealth detection equipment in the medium-wave infrared and long-wave infrared bands, and uses the medium-wave infrared (5-8μm) band for radiation heat dissipation. For example, wavelength selective emitters with thermal control management, infrared selective emitters and uses (CN116107002A), a spectrally selective low-emissivity infrared stealth coating and its preparation method and application (CN116430498B), and Ge2Sb2Te5-based infrared stealth and radiation heat dissipation film 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 signal reflected by the target; (2) the heat dissipation efficiency in the medium and long wave infrared bands is low (the maximum heat dissipation power density is 58W / m at 300K). 2 ), and did not use the very long wave infrared band with higher heat dissipation efficiency (the maximum heat dissipation power density is 171W / m at 300K). 2 ); (3) There are problems such as a large number of film layers, large thickness, and complex preparation process.

[0007] In summary, the existing multi-band stealth technology cannot simultaneously cover the extremely threatening infrared detection bands such as H, K, medium-wave infrared and long-wave infrared, and fully utilize the non-atmospheric transparent window for radiation heat dissipation. Therefore, how to design a stealth material that is easy to prepare and can achieve infrared stealth in the H, K, medium-wave infrared and long-wave infrared bands and radiation heat dissipation is an urgent problem to be solved by technicians in this field. Summary of the invention

[0008] In order to solve the problems existing in the prior art, the present invention provides a multilayer film that is compatible with stealth and radiative heat dissipation in the H, K, medium-wave infrared and long-wave infrared bands. The film can achieve stealth in the H, K, medium-wave infrared and long-wave infrared bands, and is compatible with radiative heat dissipation in the very long-wave infrared band.

[0009] The multilayer film of the present invention can achieve invisibility against solar radiation and thermal radiation while having effective radiation heat dissipation and thermal management capabilities, and can be widely used in the fields of aviation, aerospace, etc.

[0010] The technical solution adopted by the present invention is as follows:

[0011] The present invention comprises a metal reflection layer, a photonic crystal layer of a fused loss medium and an H and K band anti-reflection layer which are sequentially arranged from inside to outside or from bottom to top; and it satisfies:

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

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

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

[0015] In the above-mentioned multi-layer 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 fused with lossy media is used to achieve high absorptivity 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; the H and K band anti-reflection layer is used to improve the absorptivity 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 further preferably 90 to 150 nm.

[0018] The photonic crystal layer of the fused loss medium is a multi-layer structure, which is formed by alternately stacking layers of various high and low refractive index medium materials in a sequence from inside to outside or from bottom to top;

[0019] The dielectric material of each layer is a high refractive index dielectric material or a low refractive index dielectric material. A dielectric layer of a low refractive index dielectric material is arranged between adjacent dielectric layers of a high refractive index dielectric material, and a dielectric layer of a high refractive index dielectric material is arranged between adjacent dielectric layers of a low refractive index dielectric material.

[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, germanium antimony selenium tellurium alloy, etc., 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, zinc selenide, etc.

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

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

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

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

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

[0026] As a further preferred embodiment, the photonic crystal layer of the fused lossy medium is formed by alternately stacking four dielectric material layers with three different refractive indices.

[0027] In the present technical solution, the photonic crystal layer of the fused loss medium is formed by alternatingly stacking high and low refractive index dielectric material layers, and the high refractive index or low refractive index material can be two types; taking two types of high refractive index materials as an example, the materials of the high refractive index dielectric material layer alternately stacked with the low refractive index dielectric material layer are two types with different refractive indices.

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

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

[0030] The material of the H and K band anti-reflection layer is one or more of magnesium fluoride, ytterbium fluoride, calcium fluoride, barium fluoride, silicon dioxide, aluminum oxide, hafnium oxide, zinc oxide, zinc sulfide, zinc selenide, etc., and zinc sulfide is more preferred. The thickness of the H and K band anti-reflection layer is 100 to 400 nm, and more preferably 150 to 300 nm.

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

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

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

[0034] The multilayer film of the present invention is invisible in the H, K, medium-wave infrared and long-wave infrared bands, and needs to meet the following conditions: it has a high absorptivity (i.e., low reflectivity) in the H band of 1.5-1.8μm and the K band of 2-2.4μm to reduce the reflected signal of solar radiation. It has a low emissivity in the medium-wave infrared band of 3-5μm and the long-wave infrared band of 8-13μm to suppress its own thermal radiation signal. It has a high emissivity in the very long-wave infrared band of 13-25μm to achieve radiative heat dissipation. The multilayer film of the present invention can achieve high absorptivity in the H and K bands and low emissivity in the medium-wave infrared and long-wave infrared bands, thereby achieving a stealth effect; at the same time, it also achieves radiative heat dissipation in the very long-wave infrared band, and the preparation process is simple, which can meet the infrared multi-band stealth requirements and thermal management requirements of application scenarios such as space.

[0035] The multilayer film of the present invention, which is compatible with H, K, mid-wave infrared and long-wave infrared bands for stealth and radiation heat dissipation, comprises a substrate, a metal reflection layer, a photonic crystal layer of a fused loss medium and an H, K band anti-reflection layer, and satisfies that the absorptivity of the H and K bands is higher than 0.5, the emissivity of the mid-wave infrared and long-wave infrared bands is lower than 0.5, and the emissivity of the very long-wave infrared band is greater than 0.5. The multilayer film of the present invention has effective radiation heat dissipation thermal management capabilities while achieving the stealth capabilities of the H, K, mid-wave infrared and long-wave infrared bands, and can be widely used in the fields of aviation, aerospace, etc.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] The multilayer film of the present invention, which is compatible with stealth and radiation heat dissipation in the H, K, medium-wave infrared and long-wave infrared bands, can reduce the reflected signal of solar radiation in the H and K bands, and has the ability to counter passive H and K band infrared observation equipment; it can greatly reduce the thermal radiation signal in the medium-wave infrared and long-wave infrared bands, and has a strong ability to counter thermal detectors. At the same time, the multilayer film can achieve radiation heat dissipation in the very long-wave infrared band, has effective thermal management capabilities in extreme environments such as space, keeps aerospace vehicles within a safe temperature range, and can be widely used in the fields of aviation and aerospace. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0039] Figure 2 The simulated and experimental absorption / emission spectra of the multilayer film in Example 1 of the present invention;

[0040] Figure 3 H, K, mid-wave infrared and long-wave infrared band images of the multilayer film in Example 1 of the present invention in a simulated application scenario;

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

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

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

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

[0045] Figure 8 It is a simulated absorption / emission spectrum diagram of the multilayer film in Comparative Example 1 of the present invention;

[0046] Fig. 9 It is a schematic diagram of the structure of the multilayer film in Comparative Example 2 of the present invention;

[0047] Fig.10 This is a simulated absorption / emission spectrum of the multilayer film in Comparative Example 2 of the present invention.

[0048] Table 1 shows the average absorption / radiance of each band in the embodiments and comparative examples. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments of the specification. It should be understood that the specific embodiments described herein are only used to explain the technical solution of the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0050] The specific implementation modes of the present invention are described in detail below with reference to the accompanying drawings.

[0051] The present invention provides a multilayer film compatible with H, K, mid-wave infrared and long-wave infrared bands for stealth and radiation heat dissipation, comprising: a substrate, a metal reflection layer sequentially arranged on the surface of the substrate, a photonic crystal layer fused with a lossy medium, and an H, K band anti-reflection layer;

[0052] The substrate layer, as a mechanical support, can be appropriately adjusted in thickness as required. Specifically, the substrate material can be a solid material or a flexible material. Preferably, the substrate material is silicon.

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

[0054] The photonic crystal layer fused with lossy medium is used to achieve high absorptivity 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. Specifically, the photonic crystal layer fused with lossy medium is a multilayer structure formed by alternating stacking of multiple dielectric material layers with different refractive indices, and one or more of the materials are lossy dielectric materials in the H, K or very long wave infrared bands. Preferably, the photonic crystal layer fused with lossy medium is a multilayer structure formed by alternating stacking of three dielectric material layers with different refractive indices, including a lossy dielectric material in the H, K and very long wave infrared bands, and a lossy dielectric material in the very long wave infrared band. Preferably, the three dielectric materials are germanium, germanium antimony telluride alloy and hafnium oxide (or zinc oxide), wherein germanium antimony telluride alloy is a lossy dielectric material for H, K and very long wave infrared bands, and hafnium oxide (or zinc oxide) is a lossy dielectric material for very long wave infrared band; the thickness of the germanium layer is 300-800nm, the thickness of the germanium antimony telluride alloy layer is 100-300nm, and the thickness of the hafnium oxide (or zinc oxide) layer is 1000-2500nm.

[0055] The H and K band anti-reflection layer is used to improve the absorptivity of the H (1.5-1.8 μm) and K (1.4-2.5 μm) bands; specifically, the material of the H and K band anti-reflection layer is a dielectric material. Preferably, the dielectric material is zinc sulfide; the thickness of the zinc sulfide layer is 100-400 nm.

[0056] The present invention is further described below with reference to specific embodiments.

[0057] Embodiments of the present invention are as follows:

[0058] Example 1

[0059] like Figure 1 As shown, a multilayer film compatible with H, K, mid-wave infrared and long-wave infrared bands for stealth and radiation heat dissipation includes a substrate, a metal reflection layer, a photonic crystal layer fused with a lossy medium, and an H, K band anti-reflection layer arranged in sequence from bottom to top (or from inside to outside);

[0060] Among them, silicon is used as the substrate material; a 120nm thick nickel layer is used as the metal reflective layer; the photonic crystal layer that integrates the lossy medium is a four-layer structure, which, from bottom to top, is a 1220nm thick hafnium oxide layer, a 600nm thick germanium layer, a 1930nm thick hafnium oxide layer, and a 165nm thick germanium antimony telluride alloy layer; the H and K band antireflection layer is a 215nm thick zinc sulfide layer.

[0061] The absorption / emission rate spectrum of the multilayer film compatible with H, K, mid-wave infrared and long-wave infrared bands for stealth and radiation heat dissipation is as follows: Figure 2 As shown. Figure 2 It can be seen that the above-mentioned multilayer film realizes absorption stealth in the H and K bands, low emissivity stealth in the mid-wave infrared and long-wave infrared bands, and high emissivity heat dissipation in the very long-wave infrared band. Among them, in the H band of 1.5-1.8μm, the average absorptivity is 0.839; in the K band of 2-2.4μm, the average absorptivity is 0.633. In the mid-wave infrared band of 3-5μm, the average emissivity is 0.132; in the long-wave infrared band of 8-13μm, the average emissivity is 0.142. In the very long-wave infrared band of 13-25μm, the average emissivity is 0.798.

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

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

[0064] The heating power was set from low to high, and the surface temperatures of the multilayer film sample and the nickel film of this embodiment were recorded when they reached thermal equilibrium. The results are shown in FIG. Figure 4As shown. Under the same heating power, the temperature of the multilayer film sample proposed in the present invention is lower than that of the traditional low-emissivity surface material. For example, when the input heat power density is 1200W / m 2 When the temperature of the sample surface is 81.3℃, it is 39.8℃ lower than that of the nickel film (121.1℃). At high temperatures, the radiation heat dissipation thermal management characteristics of the designed structure have better performance.

[0065] Example 2

[0066] like Figure 5 As shown, a multilayer film compatible with H, K, mid-wave infrared and long-wave infrared bands for stealth and radiation heat dissipation includes a substrate, a metal reflection layer, a photonic crystal layer fused with a lossy medium, and an H, K band anti-reflection layer arranged in sequence from bottom to top (or from inside to outside);

[0067] Among them, silicon is used as the substrate material; a 120nm thick nickel layer is used as the metal reflective layer; the photonic crystal layer that integrates the lossy medium is a four-layer structure, which, from bottom to top, is a 1690nm thick zinc oxide layer, a 460nm thick germanium layer, a 2350nm thick zinc oxide layer, and a 151nm thick germanium antimony telluride alloy layer; the H and K band antireflection layer is a 215nm thick zinc sulfide layer.

[0068] The absorption / emission rate spectrum of the multilayer film compatible with H, K, mid-wave infrared and long-wave infrared bands for stealth and radiation heat dissipation is as follows: Figure 6 As shown. Figure 6 It can be seen that the above-mentioned multilayer film realizes absorption stealth in the H and K bands, low emissivity stealth in the mid-wave infrared and long-wave infrared bands, and high emissivity heat dissipation in the very long-wave infrared band. Among them, in the H band of 1.5-1.8μm, the average absorptivity is 0.815; in the K band of 2-2.4μm, the average absorptivity is 0.884. In the mid-wave infrared band of 3-5μm, the average emissivity is 0.324; in the long-wave infrared band of 8-13μm, the average emissivity is 0.194. In the very long-wave infrared band of 13-25μm, the average emissivity is 0.665.

[0069] Comparative Example 1

[0070] like Figure 7 As shown, a multilayer film without an H-band or K-band anti-reflection layer comprises a substrate, a metal reflection layer, and a photonic crystal layer fused with a lossy medium, which are sequentially arranged from bottom to top (or from inside to outside);

[0071] Among them, silicon is used as the substrate material; a 120nm thick nickel layer is used as the metal reflective layer; the photonic crystal layer integrating the lossy medium is a four-layer structure, which includes, from bottom to top, a 1220nm thick hafnium oxide layer, a 600nm thick germanium layer, a 1930nm thick hafnium oxide layer, and a 165nm thick germanium antimony telluride alloy layer.

[0072] The absorption / emission spectrum of the multilayer film without the anti-reflection layer in the H and K bands is as follows: Figure 8 As shown. Among them, in the H band of 1.5-1.8μm, the average absorptivity is 0.384; in the K band of 2-2.4μm, the average absorptivity is 0.605. In the medium-wave infrared band of 3-5μm, the average emissivity is 0.162; in the long-wave infrared band of 8-13μm, the average emissivity is 0.203. In the very long-wave infrared band of 13-25μm, the average emissivity is 0.791. The above-mentioned comparative example multilayer film has a low absorptivity in the H band and cannot achieve stealth in the H band.

[0073] Comparative Example 2

[0074] like Fig. 9 As shown, a multilayer film containing no lossy dielectric material in a photonic crystal layer material comprises a substrate, a metal reflection layer, a photonic crystal layer without lossy dielectric material and an H and K band anti-reflection layer arranged in sequence from bottom to top (or from inside to outside);

[0075] Among them, silicon is used as the substrate material; a 120nm thick nickel layer is used as the metal reflective layer; the photonic crystal layer of the lossless medium is a four-layer structure, which, from bottom to top, is a 1020nm thick zinc sulfide layer, a 460nm thick germanium layer, a 1540nm thick zinc sulfide layer, and a 230nm thick germanium layer; the H and K band anti-reflection layer is a 215nm thick zinc sulfide layer.

[0076] The absorption / emission rate spectrum of the multilayer film that does not contain lossy dielectric material in the above-mentioned photonic crystal layer material is as follows: Fig.10 As shown. Among them, in the H band of 1.5-1.8μm, the average absorptivity is 0.575; in the K band of 2-2.4μm, the average absorptivity is 0.322. In the medium-wave infrared band of 3-5μm, the average emissivity is 0.207; in the long-wave infrared band of 8-13μm, the average emissivity is 0.028. In the very long-wave infrared band of 13-25μm, the average emissivity is 0.107. The above-mentioned comparative example multilayer film has a low absorptivity in the K band and cannot achieve stealth in the K band; at the same time, its emissivity in the very long-wave infrared band is low, and radiative heat dissipation cannot be achieved.

[0077] The average absorptivity / emission ratios of the embodiments and comparative examples in various infrared bands are shown in Table 1.

[0078] Table 1. Average absorption / radiance of each band in the examples and comparative examples

[0079] Absorption / radiation rate H K MWIR LWR VlVI 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] Among them, the embodiments all meet the spectral requirements of being compatible with H, K, medium-wave infrared and long-wave infrared bands for stealth and radiative heat dissipation. The structure of comparative example 1 does not include H and K band anti-reflection layers, and the absorption rate in the H band is low, so stealth in the H band cannot be achieved. This comparative example illustrates the importance of H and K band anti-reflection layers for achieving compatible H-band stealth. The photonic crystal layer material of comparative example 2 does not include lossy dielectric material, and the absorption rate in the K band is low and the emissivity in the very long-wave infrared band is low, so stealth and radiative heat dissipation in the K band cannot be achieved. This comparative example illustrates the importance of a photonic crystal layer that incorporates lossy media for achieving compatible K-band stealth and radiative heat dissipation.

[0081] It will be easily understood by those skilled in the art that the above description is only 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 in the protection scope of the present invention.

Claims

1. A multilayer film compatible with H, K, mid-wave infrared and long-wave infrared bands for stealth and radiation heat dissipation, characterized in that: It includes a metal reflection layer, a photonic crystal layer of a fused loss medium, and an H and K band anti-reflection layer which are arranged in sequence from the inside to the outside or from the bottom to the top; it meets the following requirements: The infrared light absorption rate in the 1.5-1.8μm and 2-2.4μm bands is higher than 0.5; The infrared light emissivity in the 3-5μm and 8-13μm bands is less than 0.5; The infrared light emissivity in the 13-25μm band is higher than 0.

5.

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

3. The multilayer film compatible with H, K, mid-wave infrared and long-wave infrared bands for stealth and radiation heat dissipation according to claim 1, characterized in that: The photonic crystal layer of the fused loss medium is a multi-layer structure, which is formed by alternatingly stacking dielectric layers of multiple high and low refractive index dielectric materials; the dielectric material of each layer is a high refractive index dielectric material or a low refractive index dielectric material, a dielectric layer of a low refractive index dielectric material is arranged between adjacent dielectric layers of high refractive index dielectric materials, and a dielectric layer of a high refractive index dielectric material is arranged between adjacent dielectric layers of low refractive index dielectric materials.

4. The multilayer film compatible with H, K, mid-wave infrared and long-wave infrared bands for stealth and radiation 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 telluride alloy, germanium antimony selenium alloy, germanium antimony selenium telluride alloy, etc., and 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, zinc selenide, etc.

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

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

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

8. The multilayer film compatible with H, K, mid-wave infrared and long-wave infrared bands for stealth and radiation heat dissipation according to claim 6, characterized in that: The photonic crystal layer of the fused loss medium is formed by alternatingly stacking four dielectric material layers with three different refractive indices, wherein the three dielectric materials with different refractive indices are germanium, germanium antimony telluride alloy and hafnium oxide. The photonic crystal layers are, from bottom to top, a hafnium oxide layer, a germanium layer, a hafnium oxide layer and a germanium antimony telluride alloy layer, wherein the germanium layer has a thickness of 300-800nm; the germanium antimony telluride alloy layer has a thickness of 100-300nm; and there are two hafnium oxide (or zinc oxide) layers with a thickness of 1000-2500nm.

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

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

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