A three-dimensional object invisibility device

Abstract

A three-dimensional object invisibility device, comprising an outer structure (1), a first inner structure (2), a second inner structure (3), a light outlet (4) and an invisibility area (5), which is a symmetric structure in the up, down, left and right directions. The outer structure (1) is a serrated structure; the first inner structure (2) is a trapezoidal structure, which is connected to the hypotenuse surface of the outer structure (1), and the angle between the trapezoidal hypotenuse surface and the bonding surface is φ; the second inner structure (3) is a trapezoidal structure, which is bonded to the hypotenuse surface of the outer structure (1), and the angle between the trapezoidal hypotenuse surface and the bonding surface is also φ; the invisibility area (5) is surrounded by four first inner structures (2); the light outlet (4) is the area on both sides of the invisibility device, used to export the light in the invisibility area to avoid the accumulation of light energy. The structure of the present invention is simple, and the invisibility of a relatively large three-dimensional object in the visible light band can be realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of invisibility devices, and particularly relates to a three-dimensional object invisibility device, which can achieve the invisibility of a relatively large three-dimensional object in a complex background. Background Art

[0002] Invisibility designs are widely used in military and civilian fields. In the military field, three-dimensional invisibility devices can be adopted for tanks, missile launch vehicles, combat troops, etc. to avoid being observed or detected by the human eyes of the opponent, thereby improving the safety of personnel and weaponry. In the civilian aspect, optical invisibility in the visible light band can be used in fields such as interior decoration, virtual cities, and film production.

[0003] Chinese Patent CN 203744840 U discloses an optical stealth device. The stealth components used include a microprocessing unit, at least two micro cameras responsible for collecting surrounding images and electrically connected to the microprocessing unit, and at least two flexible screens electrically connected to the microprocessing unit. By displaying the scene on the back of the object in real time, the effect of stealth is achieved. Such a stealth device mainly uses the method of screen display to cause visual confusion to the naked eye, but it does not have a stealth effect on object detectors.

[0004] Chinese Patent CN106983189 A discloses a two-dimensional annular adjustable optical stealth cloak based on a multi-layer nanofluid. By controlling the nanoparticle characteristics of the nanofluid, the structure of the fluid, and the chemical composition of the nanoparticles in different annular layers, each layer can correspond to different permittivity and permeability coefficients, obtaining the two-dimensional permittivity and permeability coefficient distributions required for optical invisibility. Then, after the light rays bypass the cloak area, the light field resumes its original distribution, realizing the optical invisibility function, shielding the object located at the center of the optical stealth cloak from external light interference, and at the same time not affecting the external light field distribution. However, such an invisibility device is suitable for micro two-dimensional invisibility and not suitable for the invisibility of macroscopic three-dimensional objects.

[0005] Chinese Patent CN 106983190 A discloses a two-dimensional adjustable optical stealth cloak based on a multi-layer paraffin composite phase change material. By controlling the solid-liquid state of the paraffin composite phase change material in different annular layers, each layer can correspond to different permittivity and permeability coefficients, obtaining the two-dimensional permittivity and permeability coefficient distributions required for optical invisibility. Then, after the light rays bypass the cloak area, the light field resumes its original distribution, realizing the optical invisibility function. However, such an invisibility device is suitable for micro two-dimensional invisibility and not suitable for the invisibility of macroscopic three-dimensional objects.

[0006] Chinese Patent CN 106983188 A discloses a tunable two-dimensional optical invisibility cloak based on multi-layer graphene rings. By controlling the Fermi level distribution of graphene in different rings, different dielectric constants and magnetic permeability coefficients can be obtained for each layer, and the two-dimensional dielectric constant and magnetic permeability coefficient distribution required for optical invisibility can be obtained. Furthermore, after the light rays bypass the cloak area, the light field can return to its original distribution, achieving the optical invisibility function. However, this kind of invisibility device is applicable to micro two-dimensional invisibility and not applicable to the invisibility of macroscopic three-dimensional objects.

[0007] US Patent US 10460713B2 discloses a design method for acoustic stealth materials. Based on the connection between the acoustic wave and electromagnetic wave propagation models, the mathematical model of acoustic wave propagation is transformed to obtain the design model of acoustic stealth materials. This method is applicable to the acoustic stealth of micro-objects and not applicable to the invisibility of three-dimensional objects in the visible light band. Summary of the Invention

[0008] In order to overcome the deficiencies in the prior art, the present invention provides a three-dimensional object invisibility device to solve the problem of invisibility of macroscopic three-dimensional objects in the visible light band.

[0009] The present invention proposes a three-dimensional object invisibility device, including a left-side structure and a right-side structure; the left-side structure includes: an outer-layer structure, a first inner-layer structure, a second inner-layer structure, and a light outlet;

[0010] The outer side of the outer-layer structure is a plane, and the vertical section of the inner side is a serrated structure formed by two isosceles right triangles arranged one above the other in sequence. The vertical sections of the first inner-layer structure and the second inner-layer structure are trapezoidal structures;

[0011] The second inner-layer structure is a trapezoidal structure, one of its bottom surfaces is connected to the upper waist of the isosceles right triangle above the outer-layer structure, and the angle between the hypotenuse surface and the connecting surface of this trapezoidal structure is φ; the first inner-layer structure is a trapezoidal structure, one of its bottom surfaces is connected to the lower waist of the isosceles right triangle above the outer-layer structure, and the angle between the hypotenuse of this trapezoid and the connecting surface is also φ;

[0012] One of the bottom surfaces of the trapezoidal structure of the first inner-layer structure is connected to the upper waist of the isosceles right triangle below the outer-layer structure, and the angle between the hypotenuse of this trapezoid and the connecting surface is φ; one of the bottom surfaces of the trapezoidal structure of the second inner-layer structure is connected to the lower waist of the isosceles right triangle below the outer-layer structure, and the angle between the hypotenuse of this trapezoid and the connecting surface is also φ;

[0013] The outer structure and the first and second inner structures are connected in the above manner to form the left structure of the invisibility device. A right structure that is mirror-symmetrical to the left structure is provided on its right side. The left and right structures are closed to surround and form the invisibility device. The four first inner structures surround and form the invisible area of the invisibility device. The areas on the upper and lower sides of the invisibility device, which are formed by two opposite second inner structures, serve as light outlets.

[0014] Further, the refractive index of the outer structure is n1, and n1 satisfies:

[0015] n1·sinθ1≥1

[0016] where θ1 is the incident angle when the scattered light of the invisible object is deflected by the invisibility device and then incident on the outer interface of the device.

[0017] Further, the first inner structure and the second inner structure have the same shape and structure; the refractive indices of the first inner structure and the second inner structure are the same, which is n2, and n2 satisfies the following formula:

[0018] n1·sin45° / n2<1

[0019] n2 < n1.

[0020] Further, the connection methods between the outer structure and the first inner structure and the second inner structure include optical cementing or gluing with an adhesive. The refractive index of the adhesive is between the refractive indices of the outer structure and the first inner structure and the second inner structure.

[0021] Further, the height of the invisible area is equal to the sum of the vertical heights of the first inner structures, and the width of the invisible area is equal to the height of the invisible area.

[0022] Further, the end face of the invisible area is a square, and the half-height and half-width of the invisible area are the same, both being c; the thickness a of the outer structure is the shortest distance from the connection surface between the first inner structure and the outer structure to the outer plane of the outer structure; the thickness b of the first inner structure is the distance between two parallel planes of the first inner structure in the direction perpendicular to the outer plane of the outer structure. The calculation formula for b is as follows:

[0023] n1·sin45°=n2·sinθ

[0024] tan(θ - 45°)(b + c)=c

[0025] In the above formula, 45° is the incident angle of the background parallel light at the interface between the outer structure and the first inner structure, and θ is the exit angle of the background parallel light at the interface between the outer structure and the first inner structure.

[0026] Further, the half-width of the invisibility device = the half-height d of the invisibility device = the half-width c of the invisible area + the thickness b of the first inner layer structure + the thickness a of the outer layer structure.

[0027] Further, the calculation formula of φ is as follows:

[0028] n1sin45° = n2sinθ

[0029] α = 360° - 135° - 90° - θ - γ

[0030] β = 90° - γ

[0031] n2sinα = n1sinβ

[0032] φ = 180° - 45° - γ

[0033] Among them, the other angle corresponding to the isosceles right triangle and the connection surface of the outer layer structure is φ, the remaining angle of the isosceles right triangle is γ, θ is the exit angle when the background parallel light enters the connection surface of the isosceles right triangle and the outer layer structure from the outer layer structure with refractive index n1 and is refracted into the first inner layer structure, the incident angle of the light entering the first inner layer structure when it hits the other side of the isosceles right triangle is α, and the exit angle after refraction is β.

[0034] Further, the height of the second inner layer structure = the half-height d of the invisibility device - the half-height c of the invisible area; the thickness b of the second inner layer structure is the distance between two parallel planes of the second inner layer structure in the direction perpendicular to the outer plane of the outer layer structure.

[0035] Further, the outer layer structure is made of H-ZLAF92 optical glass, and the first inner layer structure and the second inner layer structure are made of H-K6 optical glass.

[0036] The present invention has the following beneficial effects compared with the prior art:

[0037] (1) A three-dimensional object invisibility device provided by the present invention adopts a polygonal prism structure and is processed from two materials. The structure is simple and easy to process, and can be used for the invisibility of larger three-dimensional objects;

[0038] (2) A three-dimensional object invisibility device provided by the present invention is designed based on the principle of light path propagation, combining material parameters and structural parameters. It not only realizes the guidance of the propagation path of the scattered light of the object in the invisible area, but also takes into account the guidance of the propagation path of the background scattered light of the device, and can realize the invisibility of the object to the naked eye and detectors in a complex background. Description of the Drawings

[0039] Figure 1 It is a schematic structural diagram of a three-dimensional object invisibility device provided by the present invention;

[0040] Figure 2 It is the propagation light path diagram of the scattered light of the object in the invisible area;

[0041] Figure 3 It is the dimension diagram of a three-dimensional object invisibility device;

[0042] Figure 4 It is the schematic diagram of the angle symbol.

[0043] Explanation of the reference numerals in the attached drawings

[0044] 1 - Outer structure; 2 - First inner structure; 3 - Second inner structure; 4 - Light outlet; 5 - Invisible area; 6 - Interface background; 7 - Detector. Specific implementation manner

[0045] The present invention will be described in detail below, and the features and advantages of the present invention will become clearer and more definite along with these descriptions.

[0046] According to the present invention, a three-dimensional object invisibility device is provided, which includes a left structure and a right structure symmetrical thereto, as shown in reference Figure 1 shown.

[0047] The left structure includes: an outer structure 1, a first inner structure 2, a second inner structure 3, and a light outlet 4.

[0048] The outer side of the outer structure 1 is a plane, and the vertical section of the inner side is a serrated structure formed by two isosceles right triangles arranged one above the other in sequence. The vertical sections of the first inner structure 2 and the second inner structure 3 are trapezoidal structures.

[0049] One bottom surface of the trapezoidal structure of the second inner structure 3 is bonded to the upper waist of the isosceles right triangle above the outer structure 1, and the angle between the inclined side surface of the trapezoid and the bonding surface is φ; one bottom surface of the trapezoidal structure of the first inner structure is bonded to the lower waist of the isosceles right triangle above the outer structure 1, and the angle between the inclined side surface of the trapezoid and the bonding surface is also φ.

[0050] One bottom surface of the trapezoidal structure of the first inner structure 2 is bonded to the upper waist of the isosceles right triangle below the outer structure 1, and the angle between the inclined side surface of the trapezoid and the bonding surface is φ; one bottom surface of the trapezoidal structure of the second inner structure 3 is bonded to the lower waist of the isosceles right triangle below the outer structure, and the angle between the inclined side surface of the trapezoid and the bonding surface is also φ.

[0051] The outer structure 1 and the first and second inner structures 3 are bonded in the above manner to form the left structure of the invisibility device. A right structure mirror-symmetrical to the left structure is arranged on its right side, and the left and right structures are closed and surrounded to form the invisibility device; the four pieces enclose the invisible area 5 of the invisibility device.

[0052] The invisibility device has a symmetric structure in the up-down, left-right directions. On the left side is the detector 7, and on the right side is the interface background 6. The detector 7 and the interface background 6 can be swapped with each other. The areas on the upper and lower sides of the invisibility device, which are composed of two second inner-layer structures facing each other, are the light outlets 4, used to export the light in the invisible area 5 to avoid the accumulation of light energy.

[0053] As Figure 2 shown, the scattered light of the object in the invisible area 5 is approximately a point light source diverging radially. It propagates through the first inner-layer structure 2 to the outer interface of the outer-layer structure 1 and undergoes total internal reflection. The totally internally reflected light propagates to the second inner-layer structure 3 and exits at the light outlet 4, so that the detector 7 cannot detect the scattered light of the object in the invisible area; the light of the background 6 propagates into the invisibility device and, under multiple refractions of the outer-layer structure 1 and the first and second inner-layer structures 2 and 3 of the device, bypasses the invisible area inside the device and continues to propagate in the original propagation direction to the detector 7, enabling the detector to detect the background light of the device.

[0054] The refractive index of the outer-layer structure 1 is n1, and the refractive index n1 satisfies:

[0055] n1·sinθ1≥1

[0056] where θ1 is the incident angle when the scattered light of the invisible object is deflected by the invisibility device and enters the outer interface of the device. Assuming that the scattered light of the object in the invisible area propagates along the direction perpendicular to the inner interface of the outer-layer structure after refraction by the first inner-layer structure 2, since the angle between the inner interface and the outer interface of the outer-layer structure is 45°, the incident angle θ1 of the light at the outer interface of the outer-layer structure is 45°. It is calculated that n1≥1.414, and the larger the value of n1, the smaller the proportion of the scattered light transmitted to the detector, and the better the invisibility effect. Considering comprehensively, the outer-layer structure 1 selects the H-ZLAF92 optical glass of Chengdu Guangming, and its refractive index n1 = 2.01 at 546 nm.

[0057] Both the first inner-layer structure 2 and the second inner-layer structure 3 are trapezoidal structures with the same interior angles, only different in length and width dimensions; the hypotenuse of the outer-layer structure 1 realizes the first deflection of the parallel background light beam, and the light beam deflects into the first inner-layer structure 2 and the second inner-layer structure 3, and propagates to the hypotenuse surface 2-1 of the first inner-layer structure 2 and the hypotenuse surface 3-1 of the second inner-layer structure 3 to realize the second deflection; the refractive indices of the first inner-layer structure 2 and the second inner-layer structure 3 are the same as n2, and n2 should satisfy the following formula:

[0058] n1·sin45° / n2<1

[0059] n2 < n1

[0060] The outer layer structure 1 is made of H-ZLAF92 optical glass from Chengdu Guangming. The refractive index n1 at 546 nm is 2.01. Therefore, the value range of n2 is 1.421 < n2 < 2.01. Within this range, the smaller the value of n2, the higher the height of the invisible area. However, when the value of n2 is too close to 1.421, factors such as processing tolerance and structural property error will cause total internal reflection of the background parallel light beam at the interface between the n1 and n2 structures. Therefore, considering common structures, the first inner layer structure 2 and the second inner layer structure 3 are made of H-K6 optical glass from Chengdu Guangming, and its refractive index n2 at 587 nm is 1.51.

[0061] The bonding between the outer layer structure 1, the first inner layer structure 2, and the second inner layer structure 3 can be achieved by optical cementing or gluing with an adhesive. The refractive index of the adhesive should be between the refractive indices of the outer layer structure 1 and the first and second inner layer structures. In this example, NOA61 glue with a refractive index of 1.56 is selected.

[0062] Reference Figure 3 , where a is the thickness of the outer layer structure 1, which is the shortest distance from the bonding surface between the first inner layer structure and the outer layer structure to the outer plane of the outer layer structure; b is the thickness of the first inner layer structure 2, which is the distance between two parallel planes of the first inner layer structure in the direction perpendicular to the outer plane of the outer layer structure; c is the half-height and half-width of the invisible area, and the end face of the invisible area is square; d is the half-height of the outer layer structure, and e is the distance between two parallel planes of the second inner layer structure in the direction perpendicular to the outer plane of the outer layer structure.

[0063] The thickness a of the outer layer structure 1 and the half-height c of the invisible area 5 can be designed as needed. Here, c = 10 mm is set. The thickness b of the first inner layer structure 2 depends on the refractive indices of the outer layer structure 1 and the first inner layer structure 2 and the half-height c of the invisible area. Assuming that the background light is parallel light propagating perpendicular to the outer interface of the device, the formula for calculating b is as follows:

[0064] n1·sin45° = n2·sinθ

[0065] tan(θ - 45°)(b + c) = c

[0066] In the above formula, 45° is the incident angle of the background parallel light beam at the interface between the outer layer structure 1 and the first inner layer structure 2, and θ is the exit angle of the background parallel light beam at the interface between the outer layer structure 1 and the first inner layer structure 2. It is obtained that b ≈ 12 mm.

[0067] The half-width of the invisible device = the half-height d of the invisible device = the half-width c of the invisible area + the thickness b of the first inner layer structure 2 + the thickness a of the outer layer structure 1.

[0068] The included angle between the beveled surfaces of the first and second inner-layer structures 2 and 3 and the beveled surface of the outer-layer structure 1 is φ. Since the background parallel light beam is first deflected by the inner interface of the outer-layer structure 1 (i.e., the bonding surface with the inner-layer structure) and then propagates to the beveled surface 2-1 of the first inner-layer structure 2, and is refracted by the beveled surface 2-1 into a light beam perpendicular to the outer interface of the outer-layer structure and continues to propagate forward. At this time, the calculation formula for φ is as follows:

[0069] n1sin45° = n2sinθ

[0070] α = 360° - 135° - 90° - θ - γ

[0071] β = 90° - γ

[0072] n2sinα = sinβ

[0073] φ = 180° - 45° - γ

[0074] Among them, the angles represented by α, β, γ, and θ are as Figure 4 shown. The background parallel light enters the inner-layer structure with a refractive index of n2 after being refracted from the outer-layer structure with a refractive index of n1. The end face of the outer-layer structure is serrated, and the end face of the inner-layer structure is triangular. The included angle between the bonding surface of the triangle and the outer-layer structure and the longest side of the triangle is 45°. The other angle corresponding to the bonding surface of the triangle and the outer-layer structure is The remaining angle of the triangle is γ, θ is the exit angle when the background parallel light enters the first inner-layer structure after being refracted from the bonding surface of the triangle and the outer-layer structure with a refractive index of n1. The incident angle of the light entering the first inner-layer structure when it hits the other side of the triangle is α, and the exit angle after refraction is β.

[0075] By the above formula, γ = 31.16° and φ = 103.84° are obtained.

[0076] The height of the second inner-layer structure 3 = the half height d of the stealth device - the half height c of the stealth area, or the height of the second inner-layer structure 3 = the thickness a of the outer-layer structure + the half height c of the stealth area. Assuming a = 5mm, the calculation method for the thickness e of the second inner-layer structure 3 is the same as that for the thickness b of the first inner-layer structure 2, and it is calculated that the thickness e of the second inner-layer structure 3 is approximately 18mm.

[0077] The scattered light at the background 7 of the rear interface of the device is approximately parallel light, as Figure 4As shown, through multiple refractions within the device, the light bypasses the intermediate invisible region 4, exits at the front interface of the outer structure 1 of the device, and propagates along the original path to the front detector 8. This enables the detector 8 to detect the scattered light of the background 7 at the rear interface of the device but not the scattered light of the object within the device, thereby achieving the invisibility of the object within the device. The refractive index difference between the second inner structure and the outer structure 1 also satisfies the condition that background light enters the device from the non-light-emitting port region, can bypass the intermediate invisible region 4 after multiple refractions within the device, and continue to propagate along the original path.

[0078] The present invention has been described in detail in combination with specific embodiments and exemplary examples, but these descriptions should not be construed as limiting the present invention. Those skilled in the art understand that without departing from the spirit and scope of the present invention, various equivalent substitutions, modifications, or improvements can be made to the technical solutions and their implementation manners of the present invention, and all of these fall within the scope of the present invention. The protection scope of the present invention is subject to the appended claims.

[0079] The present invention designs in combination with the material parameters and structural parameters of the device to guide the light beam to propagate along the designed path, enabling the front detector of the device to only detect the scattered light of the background at the rear interface of the device but not the scattered light of the object within the device, thereby achieving the invisibility of the object within the device. The present invention is reasonable and feasible, has a simple structure, and can achieve the invisibility of a relatively large three-dimensional object in the visible light band.

[0080] The content not detailedly described in the specification of the present invention belongs to the well-known technology of those skilled in the art.

Claims

1. A three-dimensional object invisibility device, characterized in that: It includes a left structure and a right structure; The left structure includes: an outer structure (1), a first inner structure (2), a second inner structure (3), and a light outlet (4); The outer side of the outer structure (1) is a plane, and the vertical cross-section of the inner side is a serrated structure formed by two isosceles right triangles arranged one above the other in sequence. The vertical cross-sections of the first inner structure (2) and the second inner structure (3) are trapezoidal structures; The second inner structure (3) is a trapezoidal structure, one of its bases is connected to the upper waist of the isosceles right triangle above the outer structure (1), and the angle between the hypotenuse surface and the connecting surface of this trapezoidal structure is φ; the first inner structure (2) is a trapezoidal structure, one of its bases is connected to the lower waist of the isosceles right triangle above the outer structure (1), and the angle between the hypotenuse surface and the connecting surface of this trapezoid is also φ; One of the bases of the trapezoidal structure of the first inner structure (2) is connected to the upper waist of the isosceles right triangle below the outer structure (1), and the angle between the hypotenuse surface and the connecting surface of this trapezoidal structure is φ; one of the bases of the trapezoidal structure of the second inner structure (3) is connected to the lower waist of the isosceles right triangle below the outer structure, and the angle between the hypotenuse surface and the connecting surface of this trapezoid is also φ; The outer structure (1) is connected to the first inner structure (2) and the second inner structure (3) in the above manner to form the left structure of the invisibility device. A right structure mirror-symmetrical to the left structure is arranged on its right side. The left structure and the right structure enclose and form the invisibility device; the four first inner structures (2) enclose to form an invisible area (5); the area formed by the two second inner structures (3) opposite to each other on the upper and lower sides is used as the light outlet (4); The refractive index of the outer structure (1) is n1, satisfying n1·sinθ1≥1, where θ1 is the incident angle when the scattered light of the invisible object is deflected by the invisibility device and then enters the outer interface of the invisibility device; The first inner structure (2) and the second inner structure (3) have the same shape and structure; the refractive indices of the first inner structure (2) and the second inner structure (3) are the same, both being n2, satisfying n1·sin45° / n2<1, n2 < n1; The height of the invisible area (5) is equal to the sum of the vertical heights of the first inner structures (2), and the width of the invisible area is equal to the height of the invisible area.

2. The three-dimensional object invisibility device according to claim 1, characterized in that The connection methods between the outer structure (1) and the first inner structure (2) and the second inner structure (3) include optical cementing or gluing with an adhesive. The refractive index of the adhesive is between the refractive indices of the outer structure (1) and the first inner structure (2) and the second inner structure (3).

3. The three-dimensional object invisibility device according to claim 1, characterized in that, The end face of the invisible area is a square, and the half-height and half-width of the invisible area are the same, both being c; the thickness a of the outer structure (1) is the shortest distance from the connection surface between the first inner structure (2) and the outer structure (1) to the outer plane of the outer structure; the thickness b of the first inner structure (2) is the distance between the two parallel planes of the first inner structure (2) in the direction perpendicular to the outer plane of the outer structure. The formula for obtaining b is as follows: n1·sin45° = n2·sinθ tan(θ - 45°)(b + c) = c In the formula, 45° is the incident angle of the background parallel light at the interface between the outer layer structure (1) and the first inner layer structure (2), and θ is the exit angle of the background parallel light at the interface between the outer layer structure (1) and the first inner layer structure (2).

4. The three-dimensional object invisibility device according to claim 3, characterized in that, The half-width of the stealth device = the half-height d of the stealth device = the half-width c of the stealth area + the thickness b of the first inner layer structure (2) + the thickness a of the outer layer structure (1).

5. The three-dimensional object invisibility device according to claim 4, characterized in that, The calculation formula of the said φ is as follows: n1sin45° = n2sinθ α = 360° - 135° - 90° - θ - γ β = 90° - γ n2sinα = n1sinβ φ = 180° - 45° - γ Among them, the other angle corresponding to the connection surface between the isosceles right triangle and the outer layer structure (1) is φ, the remaining angle of the isosceles right triangle is γ, θ is the exit angle of the background parallel light incident from the outer layer structure (1) with a refractive index of n1 to the connection surface between the isosceles right triangle and the outer layer structure (1) and refracted into the first inner layer structure (2), and the incident angle of the light entering the first inner layer structure (2) to the other side of the isosceles right triangle is α, and the exit angle after refraction is β.

6. The three-dimensional object invisibility device according to claim 5, characterized in that, The height of the second inner layer structure (3) = the half-height d of the stealth device - the half-height c of the stealth area; the thickness b of the second inner layer structure (3) is the distance between two parallel planes of the second inner layer structure (3) in the direction perpendicular to the outer plane of the outer layer structure (1).

7. The three-dimensional object invisibility device according to claim 1, characterized in that The outer layer structure (1) is made of H-ZLAF92 optical glass, and the first inner layer structure (2) and the second inner layer structure (3) are made of H-K6 optical glass.

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