Infrared laser composite low detectable structure

Abstract

The invention provides an infrared laser composite low detectable structure, and relates to the technical field of infrared and laser low detectable protection. The infrared laser composite low detectable structure comprises a substrate layer; the infrared laser functional layer is stacked on the substrate layer and comprises a one-dimensional photonic crystal structure, the one-dimensional photonic crystal structure comprises at least two alternately arranged materials, and the at least two alternately arranged materials correspond to different optical refractive indexes. The infrared laser composite low detectable structure is optimized according to a particle swarm algorithm, at least two or more materials with different refractive indexes are alternately arranged in space to form a photonic band gap by controlling the arrangement and thickness of the infrared laser functional layer, electromagnetic waves of a specific wave band can be reflected or absorbed, and the detection sensitivity is improved. Therefore, the infrared laser composite low detectable effect is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of infrared and laser low-detectability protection, and particularly to an infrared laser composite low-detectability structure. Background Art

[0002] With the progress of material systems, the development in the field of detectors is advancing rapidly, and there is a trend of multi-band joint detection, making it difficult for traditional single camouflage means to effectively respond. In view of this situation, it is urgent to develop multi-band composite low-detectability technology. A multi-layer thin film structure formed by arranging two different refractive index materials in a spatial arrangement with an optical thickness of 1 / 4 is called a one-dimensional photonic crystal, which forms a photonic bandgap that reflects incident electromagnetic waves. This characteristic of the one-dimensional photonic crystal has significant value for infrared laser low-detectability structures that require different reflectivities. A one-dimensional quasi-photonic crystal obtained by modifying the material system and geometric parameters of the one-dimensional photonic crystal structure can achieve scaling and shifting of the photonic bandgap. However, common low-detectability structures in the prior art usually can only target a single infrared band or laser band. Therefore, when achieving high reflectivity requirements in the infrared bands of 3μm - 5μm and 8μm - 14μm and being compatible with the low reflectivity requirement of the 10.6μm laser band, the adjustable photonic bandgap of the one-dimensional quasi-photonic crystal can perfectly solve this contradiction, and the corresponding structural parameter optimization can be combined with inverse design. Summary of the Invention

[0003] In view of the above problems, the present invention provides an infrared laser composite low-detectability structure.

[0004] According to one aspect of an embodiment of the present invention, there is provided an infrared laser composite low-detectability structure, including: a base layer; an infrared laser functional layer stacked on the base layer, including a one-dimensional photonic crystal structure, wherein the one-dimensional photonic crystal structure includes at least two alternately arranged materials, and the at least two alternately arranged materials have different corresponding optical refractive indices.

[0005] According to an embodiment of the present invention, the infrared laser functional layer further includes a metal loss reflection layer, and the material of the metal loss reflection layer includes Ag.

[0006] According to an embodiment of the present invention, the infrared laser functional layer includes, from top to bottom in sequence: a Ge layer, a ZnS layer, a Ge layer, a ZnS layer, a Ge layer, a ZnS layer, a Ge layer, an Ag layer, and a Ge layer.

[0007] According to an embodiment of the present invention, the optical refractive index of the Ge layer in the infrared band is 4.0.

[0008] According to an embodiment of the present invention, the optical refractive index of the ZnS layer in the infrared band is 2.2.

[0009] According to an embodiment of the present invention, the material of the metal loss reflection layer further includes one of Pt, Al, Au, and Cu.

[0010] According to an embodiment of the present invention, the material of the base layer includes silicon dioxide.

[0011] According to an embodiment of the present invention, the material of the base layer further includes oxide ceramics, where the oxide ceramics include one of Al2O3, single crystal sapphire, ZrO2, MgO, MgAl2O, and AlON.

[0012] According to an embodiment of the present invention, the material of the base layer further includes fluoride crystals, where the fluoride crystals include one of CaF2 and MgF2.

[0013] According to an embodiment of the present invention, the material of the base layer further includes one of graphite, ITO, Al, Au, Ag, and Pt.

[0014] The infrared laser composite low-detectability structure provided by the present invention has at least the following beneficial effects:

[0015] (1) The infrared laser composite low-detectability structure provided by the present invention is optimized according to the particle swarm algorithm. By manipulating the arrangement and thickness of the infrared laser functional layer, materials with at least two different refractive indices are alternately arranged in space to form a photonic bandgap, which can reflect or absorb electromagnetic waves in a specific band, thereby achieving the infrared laser composite low-detectability effect.

[0016] (2) The infrared laser composite low-detectability structure provided by the present invention has reflectivities as high as 0.91 and 0.90 in the 3μm - 5μm and 8μm - 14μm infrared bands, and emissivities or absorptivities as high as 0.67 and 0.98 in the 5μm - 8μm and 10.6μm bands, respectively, and has excellent infrared laser composite low-detectability ability and radiation heat dissipation ability.

[0017] (3) The infrared laser composite low-detectability structure provided by the present invention can be reversely designed and optimized to obtain an optical structure design that meets new requirements according to changes in demand, and has remarkable versatility and flexibility. Description of the Drawings

[0018] Through the following description of the embodiments of the present invention with reference to the drawings, the above-mentioned content and other objects, features, and advantages of the present invention will become clearer. In the drawings:

[0019] Figure 1 Schematically shows the structural diagram of the infrared laser composite low-detectability structure according to an embodiment of the present invention.

[0020] Figure 2A cross-sectional scan diagram of an infrared laser composite low-detectability structure according to an embodiment of the present invention is schematically shown. Detailed implementation manners

[0021] To make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the following further describes the present invention in detail with reference to specific embodiments and the accompanying drawings. Obviously, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention. The terms used herein are only for describing specific embodiments and are not intended to limit the present invention. The terms "including", "comprising", etc. used herein indicate the presence of the described features, steps, operations and / or components, but do not exclude the presence or addition of one or more other features, steps, operations or components.

[0022] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected to", "fixed", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection, an electrical connection or can communicate with each other; it can be a direct connection, or indirectly connected through an intermediate medium, and can be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "longitudinal", "length", "circumferential", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the subsystem or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0024] Throughout the drawings, the same elements are denoted by the same or similar reference numerals. When it may cause confusion in the understanding of the present invention, the conventional structures or configurations will be omitted. And the shapes, sizes, and positional relationships of the components in the drawings do not reflect the actual sizes, ratios, and actual positional relationships.

[0025] Similarly, to streamline the present invention and assist in understanding one or more of the various inventive aspects, in the above description of the exemplary embodiments of the present invention, the various features of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. Descriptions referring to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0026] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0027] In cases where expressions similar to "at least one of A, B, and C, etc." are used, generally, it should be interpreted according to the meaning usually understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include, but is not limited to, a system having only A, only B, only C, having A and B, having A and C, having B and C, and / or having A, B, and C, etc.).

[0028] In the technical solution of the present invention, the processing of the data involved (such as including but not limited to user personal information), including collection, storage, use, processing, transmission, provision, disclosure, and application, etc., all comply with the provisions of relevant laws and regulations, take necessary confidentiality measures, and do not violate public order and good customs.

[0029] Introduction to keywords:

[0030] Low observable technology, also known as stealth technology, is a technology that studies and utilizes various technical means to change the detectable information characteristics of its own targets. Stealth technology is an application and extension of traditional camouflage technology. Its emergence has transformed camouflage technology from a defensive to an offensive one, from passive to active, enhancing the survival ability of a group and increasing the deterrence against targets. For example, when radar and communication equipment operate, they emit electromagnetic waves, their surfaces reflect electromagnetic waves, running engines and other heat-generating components radiate infrared rays, and objects (such as aircraft) reflect radar waves incident on them. In this way, weaponry forms a distinct contrast with its surrounding background and is easily detectable. By various means, efforts are made to weaken its own characteristic signals as much as possible, reduce the reflection of external electromagnetic waves, light waves, and infrared rays, so as to make it indistinguishable from its surrounding background and thus conceal itself. This is "low observable technology".

[0031] One-dimensional photonic crystal: A multilayer thin-film structure formed by arranging two materials with different refractive indices in a spatial pattern of 1 / 4 optical thickness is called a one-dimensional photonic crystal, which forms a photonic bandgap that reflects incident electromagnetic waves.

[0032] Particle Swarm Optimization (PSO), also known as the particle swarm algorithm, is an evolutionary computing technology developed by J. Kennedy and R. C. Eberhart et al. in 1995, which originated from the simulation of a simplified social model. The "swarm" in it comes from the five basic principles of swarm intelligence proposed by M. M. Millonas when developing a model applied to artificial life.

[0033] Figure 1 Schematically shows the structural diagram of an infrared laser composite low observable structure according to an embodiment of the present invention.

[0034] As Figure 1 shown, the infrared laser composite low observable structure of this embodiment includes: a base layer and an infrared laser functional layer.

[0035] The infrared laser functional layer is laminated on the base layer and includes a one-dimensional photonic crystal structure, where the one-dimensional photonic crystal structure includes at least two alternately arranged materials, and the optical refractive indices of the at least two alternately arranged materials are different.

[0036] In this embodiment, the infrared laser functional layer is composed of a one-dimensional photonic crystal structure, includes more than two materials, and after being optimized by the particle swarm algorithm, forms a quasi-periodic structure in a spatially alternating arrangement.

[0037] The infrared laser composite low-detectable structure provided by the present invention is optimized according to the particle swarm algorithm. By manipulating the arrangement and thickness of the infrared laser functional layer, materials with at least two different refractive indices are alternately arranged in space to form a photonic bandgap, which can reflect or absorb electromagnetic waves in a specific band, thereby achieving the infrared laser composite low-detectable effect.

[0038] On the basis of the above embodiments, in the infrared laser composite low-detectable structure of this embodiment, the infrared laser functional layer further includes a metal loss reflection layer. The material of the metal loss reflection layer is preferably Ag. In addition, one of Pt, Al, Au, and Cu can also be selected.

[0039] On the basis of the above embodiments, the number of layers of the infrared laser functional layer in the infrared laser composite low-detectable structure of this embodiment is 5 to 12 layers. Generally speaking, the more layers, the better the low-detectable effect. However, too many layers are not conducive to optimization and manufacturing, and too few layers result in a poor low-detectable effect. Therefore, in this embodiment, a 9-layer structure is preferably selected. The infrared laser functional layer includes, from top to bottom: a Ge layer, a ZnS layer, a Ge layer, a ZnS layer, a Ge layer, a ZnS layer, a Ge layer, an Ag layer, and a Ge layer.

[0040] In this embodiment, the infrared laser functional layer contains three materials with different optical refractive indices. Among them, the optical refractive index of the Ge layer in the infrared band is 4.0. Similar high-refractive-index materials also include GST, Si, and CdSe, etc. The optical refractive index of the ZnS layer in the infrared band is 2.2. Similar low-refractive-index materials also include ZnSe, SiO2, TiO2, AlF3, MgF2, Al2O3, and ThF4, etc. In addition, the infrared laser functional layer in this embodiment can also contain two, four, five, or six materials with different optical refractive indices.

[0041] In this embodiment, the thickness of each layer of the infrared laser functional layer is reverse-designed and optimized according to the requirements of high infrared light reflectivity in the 3μm - 5μm and 8μm - 14μm bands, and low infrared reflectivity in the 5μm - 8μm and 10.6μm bands. When electromagnetic waves are incident, electromagnetic waves in the 3μm - 5μm and 8μm - 14μm bands cannot pass through the quasi-photonic crystal structure due to the photonic bandgap and are reflected back into the surrounding space, so they have high infrared reflectivity, that is, low infrared emissivity, thereby achieving low infrared detectability. Electromagnetic waves in the 5μm - 8μm and 10.6μm bands are absorbed when incident on the structure, so they have low reflectivity, that is, high emissivity or high absorptivity. This facilitates the structure to radiate heat through the 5μm - 8μm band and absorb the 10.6μm incident laser.

[0042] In this embodiment, the thicknesses of the layers of the infrared laser functional layer are optimized by using the particle swarm optimization algorithm. Among them, the thicknesses of the 9 layers of the infrared laser functional layer from top to bottom can be: 0.782, 0.689, 0.261, 0.143, 0.344, 1.969, 0.346, 0.008, 0.334, with the unit of μm.

[0043] It should be understood that the types and numerical values of the thicknesses of the above materials are only exemplary and do not limit the present invention.

[0044] In this embodiment, the particle swarm optimization algorithm optimization process for the thicknesses of the layers of the infrared laser functional layer is as follows:

[0045] (1) Use the particle swarm optimization algorithm to randomly generate a population. There are 20 individuals in the population. Each individual contains 9 random numbers in the range of 0 to 2. Each individual corresponds to an infrared laser low-detectable structure model. The 9 random numbers in the individual respectively correspond to the thicknesses of 9 thin films.

[0046] (2) Pass the individuals to the numerical simulation program, establish the corresponding simulation model and return the results.

[0047] (3) The value judgment program judges the value of each individual in the current population according to the results of each individual, and selects the best individual and the global best.

[0048] (4) The individuals in the population move towards the best individual and the global best, and the individual data changes to form a new generation of individuals and population.

[0049] (5) The new population conducts a new round of numerical simulation verification and returns the results. Judge whether the results meet the preset infrared laser transmission curve requirements. If not, repeat steps (2), (3), (4) and (5) until the conditions are met or the maximum number of loops is reached and the program automatically terminates.

[0050] The thicknesses of the layers of the infrared laser composite low-detectable structure are obtained by reverse design using optimization algorithms such as the particle swarm optimization algorithm. The reflectivities in the infrared bands of 3μm - 5μm and 8μm, 14μm are as high as 0.91 and 0.90, and the emissivities or absorptivities in the bands of 5μm - 8μm and 10.6μm are as high as 0.67 and 0.98 respectively, having excellent infrared laser composite low-detectable ability and radiation heat dissipation ability.

[0051] Figure 2 Schematically shows a cross-sectional scan view of the infrared laser composite low-detectable structure according to an embodiment of the present invention.

[0052] As Figure 2 shown, the infrared laser functional layer in the infrared laser composite low-detectable structure of the embodiment of the present invention adopts an optimal 9-layer design, fromFigure 2 Viewed in the direction shown, the infrared laser functional layer sequentially includes, from top to bottom: a Ge layer, a ZnS layer, a Ge layer, a ZnS layer, a Ge layer, a ZnS layer, a Ge layer, an Ag layer, and a Ge layer. The substrate is a silica layer.

[0053] In this embodiment, the material of the substrate is preferably silica. In addition, oxide ceramics such as Al2O3, single crystal sapphire, ZrO2, MgO, MgAl2O (spinel), and AlON (aluminum oxynitride) can also be used. Fluoride crystals such as CaF2 and MgF2 can also be used. Additionally, materials such as graphite, ITO, Al, Au, Ag, and Pt can be used.

[0054] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functions, and operations that the systems and methods according to various embodiments of the present invention may achieve. In this regard, each block in the flowchart or block diagram may represent a module, a program segment, or a part of code, and the above-mentioned module, program segment, or part of code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than that marked in the accompanying drawings. For example, two consecutive blocks shown may actually be executed substantially in parallel, and they may sometimes be executed in the reverse order, depending on the functions involved. It should also be noted that each block in the block diagram or flowchart, as well as the combination of blocks in the block diagram or flowchart, can be implemented by a dedicated hardware-based system for performing the specified functions or operations, or can be implemented by a combination of dedicated hardware and computer instructions.

[0055] Those skilled in the art can understand that the features described in the various embodiments of the present invention can be combined or combined in various ways, even if such combinations or combinations are not explicitly described in the present invention. In particular, without departing from the spirit and teachings of the present invention, the features described in the various embodiments of the present invention can be combined and combined in various ways. All such combinations and combinations fall within the scope of the present invention.

[0056] The embodiments of the present invention have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention. Although the embodiments have been described separately above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. Without departing from the scope of the present invention, those skilled in the art can make various substitutions and modifications, and all such substitutions and modifications should fall within the scope of the present invention.

Claims

1. An infrared laser composite low-detectability structure, characterized in that Comprising: Substrate layer; Infrared laser functional layer, laminated on the substrate layer, including a one-dimensional photonic crystal structure, wherein the one-dimensional photonic crystal structure includes at least two alternately arranged materials, and the optical refractive indices of the at least two alternately arranged materials are different.

2. The infrared laser composite low-detectability structure according to claim 1, wherein The infrared laser functional layer further includes a metal loss reflection layer, and the material of the metal loss reflection layer includes Ag.

3. The infrared laser composite low-detectability structure according to claim 2, wherein The infrared laser functional layer sequentially includes from top to bottom: a Ge layer, a ZnS layer, a Ge layer, a ZnS layer, a Ge layer, a ZnS layer, a Ge layer, an Ag layer, and a Ge layer.

4. The infrared laser composite low-detectability structure according to claim 3, characterized in that, The optical refractive index of the Ge layer in the infrared band is 4.

0.

5. The infrared laser composite low-detectability structure according to claim 3, wherein, The optical refractive index of the ZnS layer in the infrared band is 2.

2.

6. The infrared laser composite low-detectability structure according to claim 1, characterized in that, The material of the metal loss reflection layer further includes one of Pt, Al, Au, and Cu.

7. The infrared laser composite low-detectability structure according to claim 1, wherein The material of the substrate layer includes silica.

8. The infrared laser composite low-detectability structure according to claim 1, wherein The material of the substrate layer further includes an oxide ceramic, wherein the oxide ceramic includes one of Al2O3, single crystal sapphire, ZrO2, MgO, MgAl2O, and AlON.

9. The infrared laser composite low-detectability structure according to claim 1, wherein The material of the substrate layer further includes a fluoride crystal, wherein the fluoride crystal includes one of CaF2 and MgF2.

10. The infrared laser composite low-detectability structure according to claim 1, wherein The material of the substrate layer further includes one of graphite, ITO, Al, Au, Ag, and Pt.

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