KR102150883B1 - Dual mode encryption surface and manufacturing method thereof and display device having the same - Google Patents

Abstract

According to an embodiment of the present invention, a dual mode encryption surface includes a substrate and a dielectric layer forming a geometric metasurface on the substrate. The substrate includes a plurality of continuous unit cells, and the dielectric layer includes a plurality of nanostructures, and one or more of the nanostructures are disposed on one of the unit cells. White light emitted from a first light source is incident on the nanostructure and a spectrum is controlled to output a preset first image, and monochromatic light emitted from a second light source is incident on the nanostructure and a phase is controlled to output a preset holographic image. In the present invention, encrypted information cannot be identified in a white light area, but encrypted information can be identified when the monochromatic light is incident.

Description

A dual mode encryption surface, a manufacturing method thereof, and a display device including the same {DUAL MODE ENCRYPTION SURFACE AND MANUFACTURING METHOD THEREOF AND DISPLAY DEVICE HAVING THE SAME}

The present invention relates to a dual mode encryption surface, a method of manufacturing the same, and a display device including the same.

Recently, with the exception of those who possess specific knowledge, attempts have been made to develop encryption technologies to hide or protect specific information from others. In addition, various encryption technologies are being developed to prevent forgery and alteration of bills and famous brands. For example, in order to prevent the production of counterfeit bills or to identify counterfeit bills, hologram technology, a technology that changes patterns three-dimensionally according to viewing angles, and the like have been developed as encryption technologies.

On the other hand, when white light passes through the prism and shines on the screen, it is divided into various colors. In this way, when light travels from one medium to another, refraction occurs because the speed of light varies according to the medium. At this time, the speed of light is changed depending on the wavelength. This is called dispersion of light, and the band of dispersed light is called. It is called spectrum.

Hologram refers to a technology that can reproduce information of each part of an object in a three-dimensional shape as it is by interference between an object wave reflected from an object and a reference wave that goes straight at a different angle by using the characteristics of laser light, which is a monochromatic light. Such a hologram may be divided into a transmissive hologram in which an image is formed as the reference wave passes through the hologram device, and a reflective hologram in which an image is formed when the reference wave is reflected by the hologram device.

A conventional device that displays an image when white light is illuminated cannot implement a hologram, and a device for implementing a hologram using monochromatic light cannot display an image by spectrum.

Frequency-selective surfaces, which have a similar principle to meta-surfaces, are used in various fields such as phased array radar, but their operating frequencies are in the range of gigahertz to megahertz, which is difficult to say in the optical range, and in the optical range from visible to infrared. There is no description of a working meta surface.

Non-patent literature: Zheng, G.; Muehlenbernd, H.; Kenney, M.; Li, G.; Zentgraf, T.;Zhang, S. Metasurface Holograms Reaching 80% Efficiency. Nat. Nanotechnol. (2015)

Embodiments of the present invention have been proposed to solve the above problems, and the encrypted information cannot be identified in the white light region, but the dual mode encryption surface capable of identifying the encrypted information when monochromatic light is incident, and a method of manufacturing the same And a display device including the same.

In addition, to provide a dual mode encryption surface for storing encrypted information as a holographic image, a method of manufacturing the same, and a display device including the same.

In addition, it is intended to provide a dual mode encryption surface and a method of manufacturing the same, and a display device including the same, in which production cost is low due to mass production.

The dual-mode encryption surface according to an embodiment of the present invention includes a substrate; And a dielectric layer forming a geometric metasurface on the substrate, wherein the substrate includes a plurality of continuous unit cells, the dielectric layer includes a plurality of nanostructures, and one unit At least one nanostructure is disposed on the cell, and white light emitted from a first light source is incident on the nanostructure and the spectrum is controlled to output a preset first image, and monochromatic light emitted from the second light source is incident on the nanostructure. As a result, a predetermined hologram image may be output by controlling the phase.

The nanostructure of the dual mode encryption surface according to an embodiment of the present invention has a three-dimensional shape having a plane parallel to the XY plane, and the preset first image is output by controlling the shape and size of the nanostructure, By controlling the rotation angle of the nanostructure, the preset hologram image may be output.

The dual-mode encryption surface according to an embodiment of the present invention may have the same shape but different sizes of a nanostructure on one of the unit cells and a nanostructure on at least one other unit cell.

In the dual-mode encryption surface according to an embodiment of the present invention, a rotation angle of the nanostructure on at least one other unit cell may be different from the nanostructure on one unit cell.

In the dual mode encryption surface according to an embodiment of the present invention, the rotation angle of the nanostructure on the one unit cell is 0°, 22.5°, 45°, 67.5°, 90°, 112.5°, 135°, and It has one of 157.5°, and the rotation angle of the nanostructure on the at least one unit cell is 0°, 22.5°, 45°, 67.5°, and 90° excluding the rotation angle selected on the one unit cell. , 112.5°, 135° and 157.5°.

The nanostructure of the dual mode encryption surface according to an embodiment of the present invention has a rectangular parallelepiped shape, and the length (L) of the nanostructure on the single unit cell is 300 nm, the width (W) is 100 nm, and the height (H) may be 300 nm, the length (L) of the nanostructure on the at least one unit cell may be 300 nm, the width (W) may be 50 nm, and the height (H) may be 300 nm.

In the dual mode encryption surface according to an embodiment of the present invention, two nanostructures may be disposed on one unit cell.

In the dual mode encryption surface according to an embodiment of the present invention, a distance g between the two nanostructures disposed on one unit cell may be one of 100 nm or 150 nm.

In the dual mode encryption surface according to an embodiment of the present invention, the preset first image and the preset hologram image may be independently controlled.

In the dual mode encryption surface according to an embodiment of the present invention, the preset hologram image may be output in one color, and the preset first image may be output in at least two or more colors.

The preset hologram image output from the dual mode encryption surface according to an embodiment of the present invention may be a QR code.

The substrate of the dual mode encryption surface according to an embodiment of the present invention may be made of silicon dioxide, and the dielectric may be made of amorphous silicon.

In the dual mode encryption surface according to an embodiment of the present invention, two nanostructures on one unit cell may represent one pixel.

In the dual mode encryption surface according to an embodiment of the present invention, the first light source may be a white light source capable of projecting visible light, and the second light source may be a laser light source capable of projecting laser light.

In the dual mode encryption surface according to an embodiment of the present invention, the first image output by the white light is output on a nanostructure, and the holographic image output by the monochromatic light transmits the monochromatic light through the nanostructure. By doing so, it can be output on the rear surface of the nanostructure.

In the dual mode encryption surface according to an embodiment of the present invention, the first image output by the white light is output on a nanostructure, and the holographic image output by the monochromatic light reflects the monochromatic light on the nanostructure. As a result, it can be output on the entire surface of the nanostructure.

A method of manufacturing a dual mode encryption surface according to an embodiment of the present invention includes the steps of: forming a substrate; Depositing a dielectric layer forming a geometric metasurface on the substrate; Forming a plurality of nanostructures on the dielectric layer, wherein white light emitted from a first light source is incident to control a reflection spectrum, and a monochromatic light emitted from a second light source is incident to control a phase. May include;

A method of manufacturing a dual mode encryption surface according to an embodiment of the present invention may be implemented through a lift-off process after chromium is deposited on the dielectric layer.

According to an embodiment of the present invention, a dual mode encryption surface; And a second light source for projecting monochromatic light onto the dual-mode encryption surface to output the holographic image, wherein the monochromatic light provided through the second light source is reflected or transmitted to the encryption surface to generate a holographic image. Device can be provided.

According to an embodiment of the present invention, it is possible to provide an authentication mark including a dual mode encryption surface.

The dual-mode encryption surface and a method of manufacturing the same according to embodiments of the present invention and a display device including the same cannot identify encrypted information in a white light area, but can identify encrypted information when monochromatic light is incident.

Also, encrypted information can be stored as a holographic image.

In addition, it is possible to provide a dual-mode encryption surface with low production cost due to mass production.

1 is a partial perspective view showing a portion of a dual mode encryption surface according to an embodiment of the present invention.
2 is a schematic diagram illustrating an image output when two types of light are incident on a dual mode encryption surface according to an embodiment of the present invention.
3 is a diagram showing a phase difference of a nanostructure having a rotation angle according to an embodiment of the present invention.
4 is a graph showing spectral colors that may appear in a first image corresponding to the size of a right hexagonal nanostructure according to an embodiment of the present invention.
5 shows cross-polarized transmittance and reflectance corresponding to the wavelength of light for a nanostructure according to an embodiment of the present invention.
6 is a diagram illustrating a first image and a holographic image of a dual mode encryption surface according to an embodiment of the present invention.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.

In addition, in describing the present invention, when it is determined that a detailed description of a related known configuration or function may obscure the subject matter of the present invention, a detailed description thereof will be omitted.

1 is a partial perspective view showing a part of a dual-mode encryption surface according to an embodiment of the present invention, and FIG. 2 is an output when two types of light are incident on the dual-mode encryption surface according to an embodiment of the present invention. Show the image. In addition, the dual mode encryption apparatus 10 of FIG. 1 illustrates one unit cell 111 for convenience of description.

1 and 2, the dual mode encryption surface 10 according to an embodiment of the present invention is a device capable of hiding preset information by displaying a plurality of images according to the type of incident light. In the embodiment of the present invention, the dual mode encryption surface 10 may be understood to include a structure formed on a two-dimensional plane.

When white light is incident on the dual mode encryption surface 10, the first image 20 may be displayed, and when monochromatic light is incident, a holographic image 30 different from the first image 20 may be displayed. Here, the first image 20 may be a reflective image that is reflected on the dual mode encryption surface 10 and may be a transmission image that appears through the dual mode encryption surface 10.

The white light includes visible light, and when the human eye sees the dual mode encryption surface 10, a preset first image 20 is output.

However, before the monochromatic light such as a laser is incident on the dual mode encryption surface 10 of the present invention, the holographic image 30 is not output, so it is not known what information is stored. Therefore, the dual mode encryption surface 10 of the present invention is applicable to security technology. As an example, the dual mode encryption surface 10 of the present invention may be applied to bills and brand logos and used as an authentication mark to determine whether a product is authentic or not.

In addition, in the embodiment of the present invention, the metamaterial may be understood as a new artificial material including both electrical and magnetic elements that do not exist in nature. In addition, in the present embodiment, it can be understood that the substrate 110 and the dielectric layer 120 function as a metamaterial as a whole.

The dual mode encryption device 10 according to an embodiment of the present invention includes a substrate 110 and a dielectric layer 120 forming a geometric metasurface on the substrate. Here, the geometric meta-surface may be understood as the nanostructure 121 included in the unit cell 111 has a geometric shape and functions as a metamaterial.

The substrate 110 may be in the shape of a plate having a plane, and a plurality of unit cells 111 are formed in succession. Here, the plane is a plane extending in the X-axis and Y-axis directions, and the Z-axis is a direction perpendicular to the plane.

In addition, one unit cell 111 may have a square shape in which the length of one side is P when viewed from the front of the XY plane. Here, the length of one side of the square unit cell 111 may range from 100 nm to 1000 nm.

The material of the substrate 110 may be Indium Tin Oxide (ITO) through which electricity is conducted. In addition, the material of the substrate 110 may be silicon dioxide (SiO ₂ ). However, the material of the substrate 110 is not limited thereto, and may be made of silicon, polydimethylsiloxane, or the like.

A dielectric layer 120 having a meta surface may be provided on the upper side of the substrate 110. Here, the dielectric layer 120 may be formed of amorphous silicon, and the dielectric layer 120 may be formed of a plurality of nanostructures 121.

In addition, one nanostructure 121 may have a rectangular parallelepiped shape having a height (h), a length (L), and a width (W). However, the shape of the nanostructure is not limited thereto, and may have various shapes such as a polyhedron and a cylindrical shape.

In an embodiment of the present invention, the height (h) is the length in the Z-axis direction, the length (L) is the length of the long side of the nanostructure 121 on the XY plane, and the width (W) is the length of the short side in the nanostructure on the XY plane. Show.

In the embodiment of the present invention, it is described that one nanostructure 121 has a rectangular parallelepiped shape as an example.

In addition, one or more nanostructures 121 may be disposed on one unit cell 111. For example, two nanostructures 121 may form a pair and be disposed on one unit cell 111. That is, it may be understood that the nanostructures positioned on one unit cell 111 have the same shape and size.

In addition, when there are a plurality of nanostructures 121 disposed on the unit cell 111, the interval g between the nanostructures 121 may range from 100nm to 200nm. Here, the interval g between the nanostructures 121 may be understood as a distance between one surface of the nanostructure and one surface of the adjacent nanostructure.

3 is a diagram showing the phase difference of the nanostructure 121 having a rotation angle (θ).

Referring to FIG. 3, the phase of the laser light incident from the laser light source (second light source) is projected onto the nanostructure 121, thereby forming a holographic image 30. In this case, the phase refers to a phase difference between light entering the nanostructure 121 and light reflected by the nanostructure 121, and two lights having different phases may cause an interference phenomenon and change the intensity of light.

According to an embodiment of the present invention, each of the nanostructures 121 may be provided on the top of the unit cell 111 in a direction of incident light and a predetermined rotation angle θ. In this case, the rotation angle θ of the nanostructure 121 refers to an angle with respect to a preset direction, and the preset direction refers to a direction in which the phase difference is zero for incident light.

The nanostructure 112 disposed in one unit cell 111 may have eight types of rotation angles θ. For example, the rotation angle of the nanostructure disposed in one unit cell 111 may have one of 0°, 22.5°, 45°, 67.5°, 90°, 112.5°, 135°, and 157.5°. Here, each rotation angle may be expressed as a first rotation angle to an eighth rotation angle.

In the case of a nanostructure having a rotation angle of 0°, the phase difference is 0, in the case of a nanostructure having a rotation angle of 22.5°, the phase difference is π/4, and in the case of a nanostructure having a rotation angle of 45°, the phase difference is 2π/ 4, in the case of a nanostructure having a rotation angle of 67.5°, the phase difference is 3π/4, in the case of a nanostructure having a rotation angle of 90°, the phase difference is π, and in the case of a nanostructure having a rotation angle of 112.5°, the phase difference is In the case of a nanostructure having a rotation angle of 5π/4 and 135°, the phase difference is 6π/4, and in the case of a nanostructure having a rotation angle of 157.5°, the phase difference is 7π/4.

By combining the nanostructures having such a rotation angle, a holographic image preset by the user can be implemented.

In addition, the height, width, and length of the nanostructure 121 may affect the wavelength band in which the hologram operates, the amplitude of reflected light, and the holographic image conversion efficiency. Therefore, the dual-mode encryption surface 10 determines an approximate structure using a Finite-Difference Time-Domain (FDTD) simulation method, converts an image to be implemented through a numerical analysis method into phase information, and then corresponds thereto. The rotation angle θ of the nanostructure 121 may be determined.

In addition, the rotation angle θ may be corrected according to the height, width, and length of the nanostructure 121.

Light passing through the nanostructure 121 may be expressed by the following equation.

는 홀로그램 형성에 관여하지 않는 성분으로, 설명의 편의상 제1 성분으로 표현하며,

는 홀로그램 형성에 관여하는 성분으로 설명의 편의상 제2 성분으로 표현한다. here,

Is a component not involved in the formation of the hologram, and is expressed as the first component for convenience of explanation,

Is a component involved in the formation of a hologram and is expressed as a second component for convenience of explanation.

와

이 곱해진 형태이다. 제2 성분은 복소수이고, 이 복소수의 크기가 투과된 빛의 진폭을 의미하며 편각(argument)은 위상을 의미한다. 여기서

은 입사광이 나노구조체의 길이방향으로 선형 편광되었을 경우에 대한 투과상수이며,

는 폭 방향으로 선형 편광되었을 경우에 대한 투과상수이고, 두 값도 모두 복소수이다.

과

는 구조체의 형상에 따라 결정되는 값이며, FDTD 시뮬레이션을 통해 값을 도출해낼 수 있다.

는 구조체의 회전 각도이며

는 복소수이다. 따라서 제2 성분의

와

모두 복소수이기 때문에 이들은 편각에 영향을 준다. The second component involved in hologram formation in the above equation is

Wow

Is the multiplied form. The second component is a complex number, and the magnitude of the complex number means the amplitude of transmitted light, and the angle of the argument means the phase. here

Is the transmission constant when incident light is linearly polarized in the longitudinal direction of the nanostructure,

Is the transmission constant when linearly polarized in the width direction, and both values are complex numbers.

and

Is a value determined according to the shape of the structure, and the value can be derived through FDTD simulation.

Is the rotation angle of the structure

Is a complex number. Therefore, the second component

Wow

Since they are all complex numbers, they affect declination.

값이 두 가지 구조체에 대해 다르기 때문에 그 차이만큼

를 조절하여 보정할 수 있다. When to use two nanostructures

Since the values are different for the two structures, the difference

It can be corrected by adjusting.

이 모든 나노구조체에 대해 같기 때문에 오로지 회전 각도에 의해서만 투과광의 위상이 조절되어 따로 보정이 필요하지 않다.However, if all the nanostructures constituting the meta surface have the same shape,

Since it is the same for all of these nanostructures, the phase of the transmitted light is adjusted only by the rotation angle, so no separate correction is required.

Further, the dielectric layer 120 on the substrate 110 may function as a meta surface. Here, the meta-surface is a functional thin film made by arranging nanostructures smaller than the wavelength of the operating light, and each nanostructure can serve as an antenna that adjusts the characteristics of light such as the wavelength, wavefront, phase, and amplitude of light. have. At this time, the size of the nanostructures constituting the meta surface may be several nanometers to several hundreds of nanometers, and the thickness and arrangement of the nanostructures may vary. In general, the meta-surface may be manufactured through an electron beam lithography process, but the method of manufacturing the meta-surface is not limited thereto.

The dielectric layer 120 in this embodiment may constitute geometric metasurfaces (GEMS). In this case, the geometric meta-surface (GEMS) refers to a meta-surface that can arbitrarily adjust a phase of light reflected or transmitted according to a geometric structure, and may be based on a Pancharatnam-Berry phase. As the dielectric layer 120 may be provided as such a geometric meta-surface (GEMS), and the dual-mode encryption surface 10 uses magnetic resonances of the dielectric layer 120 provided with amorphous silicon, The size of the structure of the dual-mode encryption surface 10 can be reduced. Specifically, in order to implement a conventional geometric meta surface using titanium oxide (TiO ₂ ), a meta surface structure having a height of 600 nm or more was required, but the geometric meta surface using amorphous silicon according to the present embodiment By having a higher refractive index and a resonance characteristic that can confine light for a long time, a hologram can be implemented despite a low structure height. Accordingly, there is an effect of lowering the manufacturing cost of the dual mode encryption surface 10.

Further, according to an embodiment of the present invention, silicon nitride, gallium nitride, or titanium oxide having a lower visible light absorption rate than silicon may be applied to the dual mode encryption surface 10. In this case, the first image 20 may exhibit two or more colors and a high reflection efficiency of 70% or more, and in a holographic image, a hologram efficiency of 90% or more may be implemented in the entire visible light area.

4 is a graph showing spectral colors that may appear in a first image according to the size of a right hexagonal nanostructure. Here, the height (h) of the right hexagonal nanostructure was set to 300 nm.

In addition, when the right hexagonal nanostructure is viewed on the XY plane, the horizontal axis represents the width (W) and the vertical axis represents the length (L).

4(a) shows a change in color according to the size of the nanostructures when two nanostructures 121 are disposed on one unit cell 111, and the interval g between each nanostructure is 100 nm. .

4(b) shows a change in color according to the size of the nanostructures when two nanostructures 121 are formed on one unit cell 111, and the distance g between each nanostructure is 150nm. .

4(c) shows a change in color according to the size of the nanostructure when one nanostructure 121 is provided on one unit cell 111.

4(a) and 4(b), in the case of having two nanostructures 121 on one unit cell 111, the size of the nanostructure according to an embodiment of the present invention is a horizontal length (L) 250nm to 450nm, width (W) may be in the range of 25nm to 125nm. In addition, the interval g between each nanostructure may be in the range of 100 nm to 200 nm.

Referring to FIG. 4(c), in the case of having one nanostructure 121 on one unit cell 111, the size of the nanostructure according to an embodiment of the present invention is in a horizontal length (L) of 225nm to 425nm. , Width (W) may be in the range of 25nm to 225nm.

5 shows cross-polarized transmittance and reflectance corresponding to the wavelength of light for a nanostructure according to an embodiment of the present invention.

FIG. 5(a) shows cross-polarization transmittance when two nanostructures are paired and disposed on a unit cell, and when one nanostructure is disposed on a unit cell.

Here, the size of the nanostructures has a horizontal length (L) of 300 nm and a width (W) of 100 nm, and the distance between the two nanostructures (g) is 100 nm, and the horizontal length (L) is 300 nm, and the width (W) is 50 nm. And the interval between two nanostructures (g) is shown for a case of 100 nm.

Referring to FIG. 5(a), cross-polarization transmittance was improved by 10% in light having a wavelength of 635 nm in the paired nanostructure compared to a single nanostructure.

According to an embodiment of the present invention, since the rod structure forming a pair has a higher density than the single nanostructure, light leaking between the nanostructure and the nanostructure can be reduced. Therefore, a high hologram efficiency of 35% or more was implemented in the target wavelength region.

5(b) shows reflectance according to the wavelength of light when two nanostructures are paired and disposed on a unit cell.

Referring to FIG. 5(b), when the nanostructure has a horizontal length (L) of 300 nm and a width (W) of 100 nm, and a gap (g) of 100 nm between two nanostructures, the reflectance is highest at a wavelength of 660 nm.

In addition, when the nanostructure has a horizontal length (L) of 300 nm and a width (W) of 50 nm, and a gap (g) of 100 nm between two nanostructures, the reflectance is highest at a wavelength of 550 nm.

According to an embodiment of the present invention, when a first image is displayed, two colors and a reflection efficiency of 10% may be displayed, and when a holographic image is displayed, a hologram efficiency of 35% in a 635 nm wavelength band may be displayed.

According to an embodiment of the present invention, a second light source having a specific wavelength for reading hologram information stored on a dual mode encryption surface may be provided.

For example, according to an embodiment of the present invention, the second light source capable of transmitting monochromatic light may be a device capable of transmitting a wavelength of 635 nm. Also, the second light source may be a device that irradiates laser light having a wavelength of 635 nm.

6 is a diagram illustrating a first image and a holographic image of a dual mode encryption surface according to an embodiment of the present invention.

6(a) shows a first image that appears when white light is incident on the dual mode encryption surface 10 according to an embodiment of the present invention.

The first image shown in FIG. 6(a) was implemented in two colors using nanostructures having two sizes. Specifically, the π-shaped nanostructure part was implemented in pink, and the background color was implemented in green.

Here, the size of the nanostructure exhibiting a π shape has a horizontal length (L) of 300 nm, a width (W) of 100 nm, and a distance (g) of 100 nm between the two nanostructures.

In addition, the size of the nanostructures showing the background color surrounding the π shape has a horizontal length (L) of 300 nm, a width (W) of 50 nm, and an interval (g) of 100 nm between the two nanostructures.

6(b) shows a holographic image that appears when monochromatic light is incident on the dual module encryption surface 10 according to an embodiment of the present invention.

In the embodiment of the present invention, the holographic image is 3.1415292?? Although shown as, the holographic image is not limited thereto, and all images having a preset shape may be represented.

6(c) shows the size and arrangement of nanostructures of the dual mode encryption surface of the present invention for realizing the images of FIGS. 6(a) and 6(b).

Referring to FIG. 6(c), as described above, it is shown that nanostructures having two sizes are formed in pairs and are arranged in an array having eight types of rotation angles described above.

In addition, the dual mode encryption surface according to an embodiment of the present invention may be manufactured through the following process.

A method of manufacturing a dual mode encryption surface according to an embodiment of the present invention includes the steps of forming a substrate; Depositing a dielectric layer forming a geometric metasurface on the substrate; As the step of forming a plurality of nanostructures on the dielectric layer, the step of forming a plurality of nanostructures for controlling a spectrum by incidence of white light emitted from a first light source and controlling a phase by incident monochromatic light emitted from a second light source. Can include.

Specifically, hydrogenated amorphous silicon is deposited on a substrate through a PE-CVD (Plasma-Enhanced Chemical Vapor Deposition) process, coated with a resist, and then irradiated with an electron beam to form a pattern. Thereafter, chromium (Cr) is deposited, and the chromium layer is removed after a lift-off process and an etching process to form the dual mode encryption surface of the present invention.

Hereinafter, the operation and effect of the dual mode encryption surface and the method of manufacturing the same will be described.

According to an embodiment of the present invention, it operates as a reflective display under normal white light, but when coherent light such as a laser is illuminated, an embedded hologram image may be output.

The present invention can be applied as various security techniques because it is impossible to read the embedded phase information before irradiating the laser. Specifically, it can be applied to an authentication mark that determines the authenticity of the product by applying it to expensive products such as cash and luxury goods, and it can be used as a financial technology such as a new payment method by embedding encrypted personal information such as a QR code in the form of a hologram. Can also develop. Furthermore, when implemented in a large area process, it is possible to reproduce 3D holographic images from science fiction movies.

In the present invention, by adjusting the size and rotation angle of individual structures forming the meta-surface, it is possible to independently control the two characteristics.

In addition, the image shown on the reflective display and the hologram image reproduced by the laser can be adjusted independently and do not affect each other.

In addition, embodiments of the present invention can be used in various fields such as security, finance, and ICT as an encrypted display.

The dual mode encryption surface and the method of manufacturing the same according to the embodiment of the present invention have been described above as specific embodiments, but this is only an example, and the present invention is not limited thereto, and the widest scope according to the basic idea disclosed in the present specification Should be interpreted as having A person skilled in the art may combine and replace the disclosed embodiments to implement a pattern of a shape not indicated, but this also does not depart from the scope of the present invention. In addition, those skilled in the art can easily change or modify the disclosed embodiments based on the present specification, and it is clear that such changes or modifications also belong to the scope of the present invention.

10: dual mode encryption surface 20: first image
30: holographic image 110: substrate
111: unit cell 120: dielectric layer
121: nano structure

Claims (20)

Board; And
Comprising a dielectric layer forming a geometric metasurface on the substrate,
The substrate includes a plurality of continuous unit cells, the dielectric layer includes a plurality of nanostructures,
Two nanostructures are arranged in pairs on one of the unit cells,
The rotation angles of the two nanostructures on one of the unit cells and the two nanostructures on at least one other unit cell are different,
The rotation angle of the two nanostructures on one unit cell has one of 0°, 22.5°, 45°, 67.5°, 90°, 112.5°, 135° and 157.5°,
The rotation angles of the two nanostructures on at least one other unit cell are 0°, 22.5°, 45°, 67.5°, 90°, 112.5°, 135° excluding the rotation angle selected on one unit cell. And 157.5°,
White light emitted from the first light source is incident on the nanostructure to control the spectrum, thereby outputting a preset first image,
Monochromatic light emitted from a second light source is incident on the nanostructure and a phase is controlled to output a preset holographic image. The method of claim 1,
The nanostructure is a three-dimensional shape having a plane parallel to the XY plane,
By controlling the shape and size of the nanostructure, the preset first image is output,
By controlling the rotation angle of the nanostructure, the preset holographic image is output, the dual mode encryption surface. The method of claim 2,
A nanostructure on one unit cell and a nanostructure on at least one other unit cell have the same shape but different sizes, a dual mode encryption surface. delete delete The method of claim 1,
The nanostructure has a rectangular parallelepiped shape,
The length (L) of the nanostructure on one of the unit cells is 300 nm, the width (W) is 100 nm, the height (H) is 300 nm,
The length (L) of the nanostructure on the at least one other unit cell is 300nm, the width (W) is 50nm, the height (H) is 300nm, dual mode encryption surface. delete The method of claim 1,
The interval (g) between the two nanostructures disposed on one unit cell is one of 100nm or 150nm, the dual mode encryption surface. The method of claim 1,
The preset first image and the preset hologram image are independently controlled, dual mode encryption surface. The method of claim 1,
The preset holographic image is output in one color,
The preset first image is output in at least two or more colors, dual mode encryption surface. The method of claim 1,
The preset holographic image is a QR code, a dual mode encryption surface. The method of claim 1,
The substrate is made of silicon dioxide,
The dielectric is made of amorphous silicon, a dual mode encryption surface. The method of claim 1,
The two nanostructures on one unit cell represent one pixel, the dual mode encryption surface. The method of claim 1,
The first light source is a white light source capable of projecting visible light,
The second light source is a laser light source capable of projecting laser light, a dual mode encryption surface. The method of claim 1,
The first image output by the white light is output on the nanostructure,
The holographic image output by the monochromatic light is output on the rear surface of the nanostructure by transmitting the monochromatic light through the nanostructure. The method of claim 1,
The first image output by the white light is output on the nanostructure,
The holographic image output by the monochromatic light is output on the entire surface of the nanostructure by reflecting the monochromatic light to the nanostructure. Forming a substrate;
Depositing a dielectric layer forming a geometric metasurface on the substrate;
A step of forming a plurality of nanostructures on the dielectric layer, comprising: forming a plurality of nanostructures for controlling a spectrum by incident white light emitted from a first light source and controlling a phase by incident monochromatic light from a second light source; Including,
The substrate includes a plurality of continuous unit cells, the dielectric layer includes a plurality of nanostructures,
Two nanostructures are arranged in pairs on one of the unit cells,
The rotation angles of the two nanostructures on one of the unit cells and the two nanostructures on at least one other unit cell are different,
The rotation angle of the two nanostructures on one unit cell has one of 0°, 22.5°, 45°, 67.5°, 90°, 112.5°, 135° and 157.5°,
The rotation angles of the two nanostructures on at least one other unit cell are 0°, 22.5°, 45°, 67.5°, 90°, 112.5°, 135° excluding the rotation angle selected on one unit cell. And a method of manufacturing a dual mode encryption surface having one of 157.5°. The method of claim 17,
The dielectric layer is implemented through a lift-off process after chromium is deposited, a method of manufacturing a dual mode encryption surface. The dual mode encryption surface according to claim 1; And
And a second light source for projecting monochromatic light onto the dual-mode encryption surface so as to output the holographic image,
Monochromatic light provided through the second light source is reflected or transmitted to the encryption surface to generate a holographic image. An authentication mark comprising the dual mode encryption surface according to claim 1.

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