Middle-infrared band intensity-polarization dual-stealth device

Abstract

The invention discloses a mid-infrared band intensity-polarization dual-stealth device, which comprises a mid-infrared intensity stealth layer and a mid-infrared polarization stealth layer, and meets the requirements that the emissivity of a mid-infrared band is lower than 0.7, and the radiation polarization degree in an observation angle range of 0-85 degrees is lower than 5%. According to the invention, high transmissivity can be realized in a visible light wave band, and other visible stealth compatible capability is realized. According to the present invention, the mid-infrared band intensity stealth and polarization stealth capabilities are achieved while the flexible characteristic is provided, and the material can be simply attached to the surfaces of vehicles, clothes or other visible camouflage coatings. In addition, the device is small in structural size, light in weight, simple to prepare, easy to prepare in a large area and practical.

Description

Technical Field

[0001] The present invention belongs to the technical field of multi-dimensional stealth technology, and particularly relates to a mid-infrared band intensity-polarization dual stealth device. Background Technique

[0002] With the continuous development of detection technologies, many emerging detection technologies that combine various detection methods in multiple dimensions such as intensity, spectrum, and polarization are applied to target detection on the battlefield. Among them, infrared polarization imaging technology has great application potential in the field of target reconnaissance in modern warfare due to its characteristics of no need for calibration, including infrared intensity characteristics, large differences between artificial targets and natural environments, and strong environmental adaptability, and also poses new requirements for the stealth performance of targets.

[0003] Under infrared polarization imaging, most artificial targets will be exposed due to the high polarization characteristics of smooth surfaces, seriously threatening the battlefield survival ability of equipment. Existing traditional infrared stealth materials mainly use the structural design of multi-layer film systems to regulate the emissivity to achieve intensity stealth, and will also exhibit strong polarization characteristics at large viewing angles. Therefore, achieving compatibility between infrared intensity stealth and polarization stealth is an urgent problem to be solved in modern stealth technology. Summary of the Invention

[0004] Aiming at the problem that existing stealth devices cannot cope with infrared polarization imaging, the present invention proposes a device with low emissivity and low linear polarization degree of radiation in a wide angular range (0-85°) for infrared light in the mid-infrared band (2.5-14 μm), realizing simultaneous stealth of infrared intensity and infrared polarization covering the surface.

[0005] A mid-infrared band intensity-polarization dual stealth device, characterized in that it includes a mid-infrared intensity stealth layer and a mid-infrared polarization stealth layer arranged in sequence; the mid-infrared polarization stealth layer is located on the outer layer; and it satisfies:

[0006] The emissivity of infrared light in the 2.5-14 μm band is less than 0.7;

[0007] The linear polarization degree of radiation of infrared light in the 2.5-14 μm band is less than 5% within the 0-85° viewing angle range.

[0008] Preferably, the emissivity of the mid-infrared band intensity-polarization dual stealth device for infrared light in the 2.5-14 μm band is less than 0.5; the linear polarization degree of radiation of infrared light in the 2.5-14 μm band is less than 3% within the 0-85° viewing angle range.

[0009] As a further preference, the mid-infrared band intensity-polarization dual stealth device has an infrared emissivity lower than 0.4 for infrared light in the 2.5-14 μm band; the linear polarization degree of the infrared light radiation in the 2.5-14 μm band is lower than 2% within the observation angle range of 0-85°.

[0010] In the above-mentioned layered structure, the mid-infrared intensity stealth layer is used to achieve low emissivity stealth in the mid-infrared band (2.5-14 μm); the mid-infrared polarization stealth layer is used to achieve low polarization degree radiation in a wide angle range in the mid-infrared band (2.5-14 μm).

[0011] As a preference, both the mid-infrared intensity stealth layer and the mid-infrared polarization stealth layer are made of flexible materials.

[0012] As a preference, both the mid-infrared intensity stealth layer and the mid-infrared polarization stealth layer are visible transparent materials.

[0013] As a preference, the mid-infrared intensity stealth layer is composed of a visible transparent infrared high-reflection thin film and a flexible support layer. The visible transparent infrared high-reflection thin film is arranged on the surface of the flexible support layer, and the visible transparent infrared high-reflection thin film is arranged close to the mid-infrared polarization stealth layer.

[0014] As a further preference, the material of the visible transparent infrared high-reflection thin film is one or more of indium oxide, indium tin oxide, aluminum-doped zinc oxide, gallium-doped zinc oxide, silver nanowires. More preferably, it is indium tin oxide.

[0015] As a preference, the material of the infrared high-reflection thin film is one or more of gold, titanium, chromium, silver metal materials; the film thickness is 20-100 nm.

[0016] As a further preference, the material of the visible transparent flexible support layer is one or more of polyethylene terephthalate, polydimethylsiloxane, polyimide.

[0017] As a further more preference, the sheet resistance of the transparent conductive thin film (i.e., the material of the visible transparent infrared high-reflection thin film) is 1-200 Ω / sq. More preferably, it is 1-100 Ω / sq, more preferably 1-50 Ω / sq; more preferably 1-20 Ω / sq. As a specific preference, the sheet resistance of the material of the visible transparent infrared high-reflection thin film is 5 Ω / sq.

[0018] As a further more preference, the thickness of the flexible support layer is 1-10000 μm, more preferably 10-10000 μm, more preferably 20-1000 μm.

[0019] As a preference, the structure of the mid-infrared polarization stealth layer is a visible transparent infrared high-transmission thin film with a rough surface.

[0020] As a further preference, the visible transparent IR highly transmissive thin film material with a rough surface is one of polyethylene and styrene-ethylene-butene-styrene block copolymer thermoplastic elastomer; the thickness of the visible transparent IR highly transmissive thin film with a rough surface is 1-200 μm; more preferably 10-100 μm; even more preferably 10-50 μm; as a specific choice, the thickness of the visible transparent IR highly transmissive thin film with a rough surface is 20 μm.

[0021] As a further preference, the root mean square roughness of the surface of the visible transparent IR highly transmissive thin film with a rough surface is 1-100 μm; more preferably 1-80 μm; further preferably 1-50 μm; even more preferably 1-20 μm; more specifically preferably 6.5 μm.

[0022] As a preference, the flexible support layer material is polyethylene terephthalate; the thickness is 50-500 μm; the visible transparent IR highly reflective thin film is an indium tin oxide layer with a sheet resistance of 1-10 Ω / sq; the IR polarization stealth layer is polyethylene with a thickness of 10-30 μm.

[0023] Taking the above preferred scheme as an example, it can achieve an emissivity of 0.3 in the mid-infrared band (2.5-14 μm) and a maximum radiation polarization degree of 1.5% at an 85° observation angle.

[0024] The mid-infrared band intensity-polarization dual stealth device of the present invention includes a mid-infrared intensity stealth layer and a mid-infrared polarization stealth layer, which satisfy that the emissivity in the mid-infrared band is lower than 0.7 and the radiation polarization degree within the 0-85° observation angle range is lower than 5%. The present invention also has a high transmittance in the visible light band and has the ability to be compatible with other visible stealth. The device structure of the present invention has the characteristics of flexibility while realizing the intensity stealth and polarization stealth capabilities in the mid-infrared band, and can be simply attached to the surface of vehicles, clothing or other visible camouflage coatings.

[0025] Compared with the existing technology, the beneficial effects of the present invention are as follows:

[0026] (1) The present invention is compatible with intensity stealth and polarization stealth in the infrared band, can greatly reduce the mid-infrared radiation intensity and polarization signal, and has the ability to counter new infrared polarization detection and multi-modal intensity polarization fusion detection technologies;

[0027] (2) The present invention has low polarization degree radiation characteristics in a wide angle range and has the ability to achieve polarization stealth at different observation angles in various scenarios;

[0028] (3) The present invention adopts a flexible hierarchical structure. The overall size of the device is small, the weight is light, the preparation process is simple, it is easy to prepare in large areas and be put into practical use, and it can be applied to irregular curved surfaces. Description of the Drawings

[0029] Figure 1 Schematic diagram of the visible-transparent mid-infrared band intensity-polarization dual stealth device provided in Embodiment 1 of the present invention;

[0030] Figure 2 Experimental measurement results of the surface topography of the rough surface mid-infrared polarization stealth layer obtained by a white light diffractometer provided in Embodiment 1 of the present invention;

[0031] Figure 3 Experimental measurement results of the visible transmittance and infrared emissivity of the visible-transparent mid-infrared band intensity-polarization dual stealth device provided in Embodiment 1 of the present invention;

[0032] Figure 4 Relationship between the degree of linear polarization measured by a long-wave infrared polarization camera and the observation angle for the visible-transparent mid-infrared band intensity-polarization dual stealth device, quartz sheet, and indium tin oxide thin film provided in Embodiment 1 of the present invention. Detailed Embodiments

[0033] In order to make the objectives, technical solutions, and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with the specification drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the technical solutions of the present invention and are not used 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.

[0034] The present invention will be further described in detail below in conjunction with the specification drawings and embodiments.

[0035] Embodiment 1

[0036] As Figure 1 shown, a visible-transparent mid-infrared band intensity-polarization dual stealth device includes a mid-infrared intensity stealth layer and a mid-infrared polarization stealth layer arranged in sequence from bottom to top;

[0037] Among them, the mid-infrared intensity stealth layer has a two-layer structure, which is, from bottom to top, a 125-μm-thick flexible support layer of polyethylene terephthalate and an indium tin oxide layer with a sheet resistance of 5 Ω / sq (i.e., a visible-transparent infrared high-reflection thin film); the material of the mid-infrared polarization stealth layer is polyethylene with a thickness of 20 μm, and its root mean square surface roughness is 6.5 μm, and its surface topography is as Figure 2 shown.

[0038] The experimental measurement results of the visible transmittance and infrared emissivity of the above-mentioned visible-transparent mid-infrared band intensity-polarization dual stealth device are as follows Figure 3 shown. It can be seen from Figure 3 that the above-mentioned layered structure realizes low-emissivity stealth in the long-wave infrared band and transparency in the visible band. Among them, in the visible band of 0.3 - 0.7 μm, the average transmittance is 0.7; in the long-wave infrared band of 8 - 14 μm, the average emissivity is 0.3.

[0039] The relationship between the degree of linear polarization measured by the above-mentioned visible-transparent mid-infrared band intensity-polarization dual stealth device, quartz plate, and indium tin oxide film with the change of the observation angle under a long-wave infrared (8 - 14 μm) polarization camera is as follows Figure 4 shown. It can be seen from Figure 4 that the degree of linear polarization of the device prepared in this embodiment increases with the increase of the observation angle, but is lower than 1.5% within the observation angle range of 0 - 85°; the degree of linear polarization of indium tin oxide also increases with the increase of the observation angle and reaches 4.9% at the 85° observation angle; the degree of linear polarization of quartz increases with the increase of the observation angle and reaches the maximum value of 4.4% at the 70° observation angle, and then decreases with the increase of the observation angle. The degree of radiative linear polarization of the device prepared in this embodiment is much smaller than that of other smooth surface objects.

[0040] Those skilled in the art can easily understand 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 replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A mid-infrared band intensity-polarization dual stealth device, characterized in that It includes a mid-infrared intensity stealth layer and a mid-infrared polarization stealth layer arranged in sequence, and the mid-infrared polarization stealth layer is located on the outer layer; it satisfies that: The emissivity of infrared light in the 2.5 - 14μm band is less than 0.7; The degree of linear polarization of the infrared light radiation in the 2.5 - 14μm band is less than 5% within the observation angle range of 0 - 85°.

2. The mid-infrared band intensity-polarization dual stealth device according to claim 1, wherein Both the mid-infrared intensity stealth layer and the mid-infrared polarization stealth layer are made of flexible materials.

3. The mid-infrared band intensity-polarization dual stealth device according to claim 1, characterized in that, The mid-infrared intensity stealth layer is composed of a flexible support layer and a thin film with high infrared reflectivity arranged on the surface of the flexible support layer, and the thin film with high infrared reflectivity is arranged close to the mid-infrared polarization stealth layer.

4. The mid-infrared band intensity-polarization dual stealth device according to claim 3, wherein The material of the thin film with high infrared reflectivity is one or more of indium oxide, indium tin oxide, aluminum-doped zinc oxide, gallium-doped zinc oxide, silver nanowires; the sheet resistance of the thin film is 5 - 200Ω / sq.

5. The mid-infrared band intensity-polarization dual stealth device according to claim 3, characterized in that The material of the thin film with high infrared reflectivity is one or more of gold, titanium, chromium, silver metal materials; the thickness of the thin film is 20 - 100nm.

6. The mid-infrared band intensity-polarization dual stealth device according to claim 3, characterized in that, The material of the flexible support layer is one or more of polyethylene terephthalate, polydimethylsiloxane, polyimide; the thickness of the flexible support layer is 1 - 10000μm.

7. The mid-infrared band intensity-polarization dual stealth device according to claim 1, characterized in that, The structure of the mid-infrared polarization stealth layer is a thin film with high infrared transmittance and a rough surface.

8. The mid-infrared band intensity-polarization dual stealth device according to claim 7, wherein, The material of the thin film with high infrared transmittance and a rough surface is one or more of polyethylene, styrene-ethylene-butene-styrene block copolymer thermoplastic elastomer; the thickness of the thin film is 1 - 200μm.

9. The mid-infrared band intensity-polarization dual stealth device according to claim 7, characterized in that, The root mean square roughness of the surface of the thin film with high infrared transmittance and a rough surface is 1 - 100μm.

10. The mid-infrared band intensity-polarization dual stealth device according to claim 3, wherein The material of the flexible support layer is polyethylene terephthalate; the thickness is 50 - 500μm; the visible transparent thin film with high infrared reflectivity is an indium tin oxide layer, and the sheet resistance is 1 - 10Ω / sq; the mid-infrared polarization stealth layer is polyethylene, and the thickness is 10 - 30μm.

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