Method for simultaneously realizing color nano-printing and color holography by metasurface and metasurface

Abstract

The application discloses a method for simultaneously realizing color nano printing and color holography and a metasurface, and the method comprises the following steps: constructing a nano brick array; obtaining a color nano printing image, determining the long axis and the short axis of the nano brick in the nano brick structure unit at each position according to the color presented by the nano brick structure unit with different size parameters; obtaining a color holographic image, and determining the turning angle of the nano brick in the nano brick structure unit at each position; arranging the nano brick structure unit with the corresponding size at each position according to the corresponding nano brick turning angle determined above, and obtaining the required metasurface; and incident white light on the metasurface, and the reflected light forms a color nano printing image on the metasurface; and incident circularly polarized light with wavelengths of λ R , λ G , λ B on the metasurface, and a color holographic image is displayed on the design distance plane. The application can realize the display multiplexing of the color nano printing image and the color holographic image simultaneously by using one metasurface, and the information storage density is high.

Description

Technical Field

[0001] This invention belongs to the field of micro-nano optical technology, specifically relating to a method and metasurface for simultaneously realizing color nanoprinting and color holography. Background Technology

[0002] Structural color is an optical phenomenon where the color of an object's surface is not determined by the object's own pigments or dyes, but rather by the surface's microstructure, texture, or geometry. This phenomenon is produced through optical effects such as light interference, diffraction, and scattering. When light shines on the surface of an object with a specific structure, the light undergoes multiple reflections, refractions, and interferences, ultimately forming light with a certain wavelength and phase difference, exhibiting a specific color. This color is usually bright and regular, and changes with the viewing angle or the angle of the light source. Structural color exists in many natural and man-made objects, such as butterfly wings, bird feathers, shells, fish, insects, oil films, and pearls. The principles of structural color can also be used to create artworks, optical components, and optical coatings for applications such as reflection, filtering, and color displays.

[0003] Holography is an optical technique for recording and reproducing three-dimensional images. It utilizes the principle of light interference to record the three-dimensional information of an object and, under appropriate conditions, reconstruct it, allowing the observer to see an image with a sense of depth and dimension. Unlike traditional photography, holography records the interference and phase information of light, not just the brightness and color of an object. Therefore, holographic images have many unique characteristics, such as strong three-dimensionality, high realism, and the ability to be viewed from different angles. Holography has wide applications in scientific research, artistic creation, information storage, and security authentication.

[0004] Metasurfaces are surfaces with special micro / nano structures used to modulate the propagation and interaction of light. They are artificially created structures that control optical effects such as the propagation, reflection, and refraction of incident light through oriented micro-elements or nanostructures.

[0005] Extensive research has already utilized metasurfaces to achieve color nanoprinted image display and color holographic image display, respectively. However, research on metasurfaces that simultaneously achieve the dual display of color nanoprinted images and color holographic images using a single metasurface is still rare. Achieving the dual display of color nanoprinted images and color holographic images through metasurfaces holds significant application potential in areas such as improving information storage density and information encryption. Summary of the Invention

[0006] The purpose of this invention is to provide a method and a metasurface for simultaneously realizing color nanoprinting and color holography using a single metasurface, thereby enabling the display and reuse of color nanoprinted images and color holographic images.

[0007] The technical solution adopted in this invention is as follows:

[0008] A method for simultaneously achieving color nanoprinting and color holography on a metasurface includes the following steps:

[0009] A nanobrick array is constructed, which consists of multiple nanobrick structural units arranged in an array. Nanobrick structural units with different size parameters exhibit different colors under white light incident. Here, different size parameters refer to the different major and minor axes of the nanobricks in the nanobrick structural units.

[0010] Obtain color nanoprinted images, and determine the major and minor axes of nanobricks in nanobrick structural units at each location based on the colors presented by nanobrick structural units with different size parameters.

[0011] Acquire color holographic images and extract the R, G, and B components; design nanobrick structure units with different size parameters at three wavelengths (λ) in red, green, and blue. R , λ G , λ B The transmission coefficients of the major and minor axes and the complex amplitude modulation effect of anisotropic nanobricks on circularly polarized light are used to determine the turning angle θ of the nanobricks in the nanobrick structural unit at each position, so that when three coherent light sources of the designed wavelengths are incident, a color holographic image is displayed on the designed distance plane.

[0012] The nanobrick structural units of corresponding sizes at each location are arranged according to the determined nanobrick orientation angles to obtain the desired metasurface; unpolarized white light is incident on the metasurface, and after passing through the metasurface, the reflected light forms the colored nanoprinted image on the metasurface; a wavelength of λ is used... R , λ G , λ B Circularly polarized light is incident on the metasurface to display the color holographic image on a designed distance plane.

[0013] Furthermore, nanobrick structural units with different size parameters have different reflectance spectral responses, and nanobrick structural units with different reflectance spectral responses exhibit different colors under white light incident.

[0014] Furthermore, the nanobrick structural unit includes a working surface and nanobricks disposed on the working surface.

[0015] Furthermore, the working surface is made of Al2O3, and the nano-bricks are made of silicon material.

[0016] Furthermore, an xoy coordinate system is established with the directions parallel to the two sides of the working surface as the x-axis and y-axis, respectively. The nanobrick has a major axis L and a minor axis W on the surface parallel to the working surface. The nanobrick's turning angle θ is the angle between the major axis L and the x-axis of the nanobrick.

[0017] Furthermore, determining the orientation angle of the nanobricks within the nanobrick structural unit at each location includes:

[0018] When the major axis L and minor axis W of the nanobrick are not equal, their equivalent refractive indices along the major and minor axes are different, and the nanobrick exhibits anisotropy. When a circularly polarized light wave is incident on the anisotropic structure, the outgoing light wave consists of two parts: one part is a light wave with the same polarization direction as the incident light wave, and the other part is a light wave with the opposite polarization direction to the incident light wave. The Jones vector of the incident circularly polarized light is... At that time, the Jones vector E of the emitted light wave out for:

[0019]

[0020] Where A and B are the complex transmission coefficients along the long and short axes of the nanobrick, respectively, and θ is the turning angle of the anisotropic nanobrick; σ = 1 and σ = -1 represent that the polarization state of the light wave is left-handed circularly polarized light or right-handed circularly polarized light, respectively.

[0021] For anisotropic nanobrick structures, when incident circularly polarized light waves, the complex amplitude modulation of the outgoing cross-polarized circularly polarized light is as follows:

[0022]

[0023] From equation (2), we can see that for nanobricks with complex transmission coefficients A and B on the major and minor axes, the complex amplitude modulation of cross-polarized circularly polarized light can be achieved by changing their orientation angle θ.

[0024] In the Fresnel diffraction region, the Fresnel diffraction formula expresses the incident light field as the amplitude and phase of the wavefront, and then calculates the new wavefront amplitude and phase over the propagation distance by integration, specifically:

[0025]

[0026] In the formula, the parameter Let be the complex amplitude at position (x1, y1) on the metasurface, k be the wavenumber, λ be the wavelength, and z1 be the observation distance. To observe the complex amplitude at position (x, y) on the surface;

[0027] It is evident that even with the same initial complex amplitude distribution and the same diffraction distance, the intensity distribution of the diffracted light will differ when the wavelength of the light wave changes.

[0028] For the three design wavelengths λ: red, green, and blue R , λ G , λ B The orientation angle distribution of the nanobrick array is θ. When a circularly polarized light wave is incident, the complex amplitude modulation of the outgoing cross-polarized circularly polarized light is:

[0029]

[0030] In the formula, For the complex amplitudes at three design wavelengths: red, green, and blue, A R B R A G B G A B B B The complex transmission coefficients of the major and minor axes are given for the three design wavelengths: red, green, and blue.

[0031] For the design distance z, the light intensity distributions corresponding to the three design wavelengths are as follows:

[0032]

[0033] In the formula, I R I G I B The light intensity distribution corresponding to the three design wavelengths: red, green, and blue;

[0034] The R, G, and B components of the color holographic image were extracted to Img. R 1mg G 1mg B Define the Loss function as follows:

[0035]

[0036] Where M and N are the number of pixel rows and columns of the color holographic image;

[0037] The turning angle θ of the nanobricks in the nanobrick structural unit at each location was obtained through optimization.

[0038] Further optimization methods include the Adam optimization algorithm.

[0039] Furthermore, three design wavelengths, λ, are used: red, green, and blue. R , λ G , λ B The wavelengths are 480nm, 532nm, and 632.8nm.

[0040] Furthermore, the design distance z is 1000μm.

[0041] A metasurface, designed using any one of the methods described above for simultaneously realizing color nanoprinting and color holography, stores both a color nanoprinted image and a color holographic image. Unpolarized white light is incident on the metasurface; after passing through the metasurface, the reflected light forms the color nanoprinted image on the metasurface. A wavelength of λ... R , λ G , λ B Circularly polarized light is incident on the metasurface to display the color holographic image on a designed distance plane.

[0042] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0043] This invention enables the simultaneous display and reuse of color nanoprinted images and color holographic images using a single metasurface: unpolarized white light is incident on the metasurface, and the reflected light forms a color nanoprinted image on the metasurface; using wavelength λ... R , λ G , λ B The circularly polarized light incident on the metasurface can display color holographic images on a designed distance plane without the need for a polarizer and analyzer, resulting in high information storage density. Attached Figure Description

[0044] Figure 1 This is a flowchart of the metasurface material design method of the present invention that simultaneously realizes color nanoprinting and color holography;

[0045] Figure 2 This is a schematic diagram illustrating the reuse of color nanoprinting and color holography in an embodiment of the present invention;

[0046] Figure 3 This is a schematic diagram of the structure of the nano-brick structure unit in an embodiment of the present invention;

[0047] Figure 4 This is a schematic diagram of the metasurface array structure in an embodiment of the present invention;

[0048] Figure 5 This is a simulation result of the reflectance spectrum of the optimized nanobrick structure unit in the embodiment of the present invention;

[0049] Figure 6 This is the target image of color nanoprinting in the embodiments of the present invention;

[0050] Figure 7 It is a color holographic target image in the embodiments of the present invention;

[0051] Figure 8 It is the R component image of the color holographic target image in the embodiments of the present invention;

[0052] Figure 9 It is the G component image of the color holographic target image in the embodiment of the present invention;

[0053] Figure 10 This is the B component image of the color holographic target image in this embodiment of the invention;

[0054] Figure 11 This is a geometric phase distribution diagram of the metasurface designed in the embodiments of the present invention;

[0055] Figure 12 This is an orientation angle distribution diagram of the metasurface nanobrick unit structure designed in the embodiments of the present invention;

[0056] Figure 13 This is a light intensity distribution diagram of the optimized metasurface in the IR wavelength incident design plane in an embodiment of the present invention;

[0057] Figure 14 This is a light intensity distribution diagram of the optimized metasurface in the IG wavelength incident design plane in an embodiment of the present invention;

[0058] Figure 15 This is a light intensity distribution diagram of the optimized metasurface in the IB wavelength incident design plane in an embodiment of the present invention.

[0059] In the figure, 1. Incident light wave; 2. Metasurface array; 3. Transmitted light wave; 4. Color nanoprinted image; 5. Color holographic display image; 6. Working surface; 7. Nanobrick. Detailed Implementation

[0060] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0061] This invention provides a metasurface material and its design method for simultaneously realizing color nanoprinting and color holography. The method includes the following steps: constructing a nanobrick array comprising multiple nanobrick structural units with a turning angle of θ; optimizing the design of multiple sets of nanobrick size parameters that display different structural colors under white light, and determining the major and minor axis dimensions of the nanobricks based on the color distribution of the color nanoprinting target image; extracting the R, G, and B components of the color holographic target image, and determining the nanobrick structural units at three designed wavelengths λ. R , λ G , λ BThe complex amplitude modulation effect is applied, and the steering angle θ is optimized using an optimization algorithm. The obtained nanobricks with their major and minor axis dimensions and steering angle θ are arranged to obtain the desired metasurface material. Unpolarized white light is incident on the metasurface, and the reflected light forms a color nanoprinted image. A laser of a designed wavelength is incident on the metasurface, and a color holographic image is displayed on a plane at a designed distance. The metasurface material provided by this invention has a high information storage density.

[0062] The present invention relates to a metasurface material and its design method that simultaneously realizes color nanoprinting and color holography, comprising the following steps:

[0063] A nanobrick array is constructed, which includes multiple nanobrick structural units. The nanobricks of each structural unit have a nanobrick turning angle of θ. Multiple sets of size parameters with different spectral responses are optimized. Nanobrick structural units with different reflection spectral responses can exhibit different structural colors under white light incident.

[0064] To design a color nanoprinted display image, based on the reflective color of the nanobrick structural units with different spectral responses, the nanobrick structural units with the closest color to the design are selected for arrangement, and the long axis and short axis of the nanobricks are determined.

[0065] Design color holographic images, extract the R, G, and B components of the color holographic images, and design nanobrick structure units with different size parameters at three wavelengths (λ) in red, green, and blue. R , λ G , λ B The transmission coefficients of the major and minor axes and the complex amplitude modulation effect of anisotropic nanobricks on circularly polarized light are analyzed. The Adam algorithm is used to design the nanobrick turning angle θ in each nanobrick structural unit so that when three coherent light sources of the designed wavelengths are incident, the target color image is displayed on the designed distance plane.

[0066] The nanobrick structural units of corresponding sizes at each location are arranged according to the corresponding nanobrick orientation angles determined in the above steps to obtain the desired metasurface material. Unpolarized white light is incident on the metasurface material; after passing through the metasurface, the reflected light forms a color nanoprinted image on the metasurface. A wavelength of λ is used... R , λ G , λ B Circularly polarized light is incident on the metasurface material to display a color holographic image on a designed distance plane.

[0067] Among them, the display of color nanoprinted images uses a metasurface operating in reflection mode with unpolarized white light as the incident light, eliminating the need for polarizers and analyzers; the display of color holographic images uses a metasurface operating in transmission mode with incident light at the designed wavelength λ. R , λ G , λ B The laser.

[0068] The major and minor axes of the nanobrick structural units are determined by color nanoprinted images. The major and minor axes of the nanobricks are not equal, and the heights of the nanobricks may be equal or unequal. The turning angle of the nanobrick structural units is determined by color holographic target images, and the Adam algorithm is used to design the turning angle of each nanobrick in each nanobrick structural unit.

[0069] The metasurface is made of SOS (Silicon-on-Sapphire) material, meaning the working surface is made of Al2O3 and the nanobricks are made of silicon.

[0070] The embodiments of the present invention provide metasurface materials and their design methods that simultaneously achieve color nanoprinting and color holography, such as... Figure 1 As shown, it includes the following steps:

[0071] A nanobrick array is constructed, comprising multiple nanobrick structural units. The nanobricks of each unit have a turning angle of θ. Multiple sets of size parameters with different spectral responses are optimized. Nanobrick structural units with different reflectance spectral responses exhibit different structural colors under white light incident light. A color nanoprinted display image is designed. Based on the reflectance colors of the nanobrick structural units with different spectral responses, the nanobrick structural units closest to the designed colors are selected for arrangement, and the major and minor axes of the nanobricks are determined. A color holographic image is designed. The R, G, and B components of the color holographic image are extracted, and the nanobrick structural units with different size parameters are arranged at three designed wavelengths λ (red, green, and blue). R , λ G , λ B The transmission coefficients of the major and minor axes and the complex amplitude modulation effect of anisotropic nanobricks on circularly polarized light are considered. The Adam algorithm is used to design the nanobrick turning angle θ in each nanobrick structural unit, ensuring that when three coherent light sources of designed wavelengths are incident, a target color image is displayed on the designed distance plane. Nanobrick structural units of corresponding sizes at each location are arranged according to the corresponding nanobrick turning angles determined in the above steps to obtain the desired metasurface material. Unpolarized white light is incident on the metasurface material; after passing through the metasurface, the reflected light forms a color nanoprinted image on the metasurface. A wavelength of λ is used... R , λ G , λ B Circularly polarized light is incident on the metasurface material to display a color holographic image on a designed distance plane.

[0072] like Figure 2 As shown, when the incident light wave 1 is incident on the metasurface array 2, a color nanoprinted image 4 will be formed on the metasurface, and the transmitted light wave 3 will display a color holographic image 5 on the designed distance plane.

[0073] like Figure 3 and Figure 4 As shown, the nanobrick structure unit includes a working surface 6 and nanobricks 7 disposed on the working surface. The metasurface is made of SOS (Silicon-on-Sapphire) material, that is, the working surface 6 is made of Al2O3 and the nanobricks 7 are made of silicon. An xoy coordinate system is established with the directions parallel to the two sides of the working surface as the x-axis and y-axis, respectively. The nanobrick has a major axis L and a minor axis W on the surface parallel to the working surface. The nanobrick's turning angle θ is the angle between the major axis L and the x-axis. The side length of the working surface is designed to be C = 400 nm, and the height of the nanobrick is fixed at H = 230 nm. The major axis L and minor axis W of the nanobrick are scanned, and the reflection spectrum of the nanobrick structure unit with various dimensional parameters is obtained through simulation, as shown below. Figure 5 As shown. Based on the reflectance spectra of the nanobrick structure units with various size parameters, the colors of various nanobrick structure units under standard light source D65 illumination were calculated. (Select as shown...) Figure 6 The color image shown is used as the near-field structured color to display the target image, according to Figure 6 The colors of each pixel and the colors of nanobricks with various size parameters are used to determine the major axis L and minor axis W of the nanobrick structural units at various locations on the metasurface.

[0074] The structural parameters of the nanobrick structure unit include the major axis L, minor axis W, height H, and the side length C of the working surface of the nanobrick, and the major axis L and minor axis W are not equal. When the major axis L and minor axis W of the nanobrick are not equal, its equivalent refractive index along the major axis direction and the minor axis direction is different, and the nanobrick exhibits anisotropy. When a circularly polarized light wave is incident on the anisotropic structure, the outgoing light wave consists of two parts: one part is a light wave with the same polarization direction as the incident light wave, and the other part is a light wave with the opposite polarization direction to the incident light wave. The Jones vector of the incident circularly polarized light is... At that time, the Jones vector of the emitted light wave is:

[0075]

[0076] Where A and B are the complex transmission coefficients along the long and short axes of the nanobrick, respectively, θ is the turning angle of the anisotropic nanobrick, and σ = 1 and σ = -1 represent that the polarization state of the light wave is left-handed circularly polarized light or right-handed circularly polarized light, respectively.

[0077] For anisotropic nanobrick structures, when incident circularly polarized light waves, the complex amplitude modulation of the outgoing cross-polarized circularly polarized light is as follows:

[0078]

[0079] As can be seen from equation (2), for nanobricks with complex transmission coefficients A and B on the major and minor axes respectively, the complex amplitude modulation of cross-polarized circularly polarized light can be achieved by changing its orientation angle θ.

[0080] The Fresnel formula considers the interference and diffraction effects of light waves during propagation, and provides an expression for the diffraction field through complex mathematical calculations. In the Fresnel diffraction region, the Fresnel diffraction formula expresses the incident light field as the amplitude and phase of the wavefront, and then calculates the new wavefront amplitude and phase over the propagation distance through integration, specifically:

[0081]

[0082] In the formula, the parameter Let be the complex amplitude at position (x1, y1) on the metasurface, k be the wavenumber, λ be the wavelength, and z1 be the observation distance. To observe the complex amplitude at position (x, y) on the surface.

[0083] It is evident that even with the same initial complex amplitude distribution and the same diffraction distance, the intensity distribution of the diffracted light will differ when the wavelength of the light wave changes.

[0084] Choose as Figure 7 The color image shown is a color holographic target image, and its R, G, and B components correspond to the image Img. R 1mg G 1mg B Each as Figure 8 , Figure 9 , Figure 10 As shown. 480nm, 532nm, and 632.8nm were chosen for the red, green, and blue design wavelengths, respectively. R , λ G , λ B The holographic design has an observation distance of 1000μm, but other distance values ​​can also be used as needed.

[0085] For the three design wavelengths λ: red, green, and blue R , λ G , λ B The orientation angle distribution of the nanobrick array is θ. When a circularly polarized light wave is incident, the complex amplitude modulation of the outgoing cross-polarized circularly polarized light is:

[0086]

[0087] In the formula, For the complex amplitudes at three design wavelengths: red, green, and blue, A R B R A G B G A B B B The complex transmission coefficients of the major and minor axes are given for the three design wavelengths of red, green, and blue.

[0088] For the design distance z, the light intensity distributions corresponding to the three design wavelengths are as follows:

[0089]

[0090] Furthermore, the R, G, and B components of the color holographic image were extracted to Img. R 1mg G 1mg B The Adam-optimized loss function is defined as follows:

[0091]

[0092] Where M and N are the number of pixel rows and columns of the target image, specifically 1000 and 1000 respectively.

[0093] The optimized geometric phase distribution of the nanobrick array is as follows: Figure 11 As shown, the corresponding angular distributions of the nanobricks are respectively as follows: Figure 12 As shown.

[0094] It should be noted that the optimization algorithm of formula (6) is not limited to the Adam optimization algorithm. Common loss function optimization algorithms are also acceptable, such as ant colony optimization, genetic optimization, simulated annealing, particle swarm optimization, etc.

[0095] The Fresnel formula shown in Equation (6) was used to verify the diffraction pattern of the optimized nanobrick array at a diffraction distance of z = 1000 μm. The light intensity distribution patterns when the incident wavelengths were 480 nm, 532 nm, and 632.8 nm were as follows: Figure 13 , Figure 14 and Figure 15 As shown, holographic images have high image quality.

[0096] The present invention provides a metasurface material that simultaneously realizes color nanoprinting and color holography. The design process is simple, the algorithm complexity is low, the image display quality is high, the crosstalk is low, and the information storage density is high.

[0097] It should be noted that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0098] It should be noted that, depending on the implementation needs, the various steps / components described in this application can be broken down into more steps / components, or two or more steps / components or parts of the operation of steps / components can be combined into new steps / components to achieve the purpose of this invention.

[0099] Those skilled in the art will readily understand that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for simultaneously realizing color nanoprinting and color holography on a metasurface, characterized in that, Includes the following steps: A nanobrick array is constructed, which consists of multiple nanobrick structural units arranged in an array. Nanobrick structural units with different size parameters exhibit different colors under white light incident. Here, different size parameters refer to the different major and minor axes of the nanobricks in the nanobrick structural units. Obtain color nanoprinted images, and determine the major and minor axes of nanobricks in nanobrick structural units at each location based on the colors presented by nanobrick structural units with different size parameters. Acquire color holographic images and extract the R, G, and B components; design nanobrick structure units with different size parameters for red, green, and blue wavelengths. , , The transmission coefficients of the major and minor axes and the complex amplitude modulation effect of anisotropic nanobricks on circularly polarized light were used to determine the turning angle of the nanobricks in the nanobrick structural unit at each location. This allows a color holographic image to be displayed on the design distance plane when coherent light sources of three design wavelengths are incident. The nanobrick structural units of corresponding sizes at each location are arranged according to the determined nanobrick orientation angles to obtain the desired metasurface; unpolarized white light is incident on the metasurface, and after passing through the metasurface, the reflected light forms the colored nanoprinted image on the metasurface; a wavelength of... , , Circularly polarized light is incident on the metasurface to display the color holographic image on a designed distance plane; Among them, determining the orientation angle of the nanobricks in the nanobrick structural unit at each location includes: When the long axis of the nanobrick L With short axis W When the values ​​are unequal, their equivalent refractive indices along the major and minor axes differ, resulting in anisotropy in the nanobricks. When circularly polarized light is incident on the anisotropic structure, the outgoing light consists of two parts: one part has the same polarization direction as the incident light, and the other part has the opposite polarization direction. The Jones vector of the incident circularly polarized light is... At that time, the Jones vector of the emitted light wave for: in, A and B These are the complex transmission coefficients along the long and short axes of the nanobrick, respectively. The turning angle of the anisotropic nanobrick; and These respectively indicate that the polarization state of the light wave is either left-handed circularly polarized light or right-handed circularly polarized light; For anisotropic nanobrick structures, when incident circularly polarized light waves, the complex amplitude modulation of the outgoing cross-polarized circularly polarized light is as follows: From the formula Therefore, the complex transmission coefficients for the major and minor axes are respectively: A and B Nanobricks, by changing their orientation angle To achieve complex amplitude modulation of cross-polarized circularly polarized light; In the Fresnel diffraction region, the Fresnel diffraction formula expresses the incident light field as the amplitude and phase of the wavefront, and then calculates the new wavefront amplitude and phase over the propagation distance by integration, specifically: In the formula, the parameter Position on the metasurface The complex amplitude, For wave number, For wavelength, To observe the distance, To observe the position on the surface Complex amplitude at the location; For the three design wavelengths of red, green, and blue , , The directional angle distribution of the nanobrick array is as follows: When an incident circularly polarized light wave is emitted, the complex amplitude modulation of the emitted cross-polarized circularly polarized light is as follows: In the formula, , , The complex amplitude is designed for red, green, and blue wavelengths. , , , , , The complex transmission coefficients of the major and minor axes are given for the three design wavelengths: red, green, and blue. For the design distance z, the light intensity distributions corresponding to the three design wavelengths are as follows: In the formula, , , The light intensity distribution corresponding to the three design wavelengths: red, green, and blue; The R, G, and B components of the color holographic image were extracted as follows: , , Define the Loss function as follows: Where M and N are the number of pixel rows and columns of the color holographic image; The directional angle of the nanobricks in the nanobrick structural unit at each location was optimized. .

2. The method for simultaneously realizing color nanoprinting and color holography on a metasurface according to claim 1, characterized in that, Nanobrick structural units with different size parameters have different reflectance spectral responses, and nanobrick structural units with different reflectance spectral responses exhibit different colors under white light incident.

3. The method for simultaneously realizing color nanoprinting and color holography on a metasurface according to claim 1, characterized in that, The nanobrick structural unit includes a working surface and nanobricks set on the working surface.

4. The method for simultaneously realizing color nanoprinting and color holography on a metasurface according to claim 3, characterized in that, Working face adopts Nanobricks are made from silicon materials.

5. The method for simultaneously realizing color nanoprinting and color holography on a metasurface according to claim 3, characterized in that, Let the directions parallel to the two sides of the working surface be respectively set as x shaft and y Axis establishment xoy A coordinate system is established, with a major axis on the surface of the nanobrick parallel to the working surface. L and short axis W Nanobrick turning angle For the long axis of nano bricks L and x The included angle of the axis.

6. The method for simultaneously realizing color nanoprinting and color holography on a metasurface according to claim 1, characterized in that, Optimization methods include the Adam optimization algorithm.

7. The method for simultaneously realizing color nanoprinting and color holography on a metasurface according to claim 1, characterized in that, Red, green, and blue design wavelengths , , The wavelengths are 480nm, 532nm, and 632.8nm.

8. The method for simultaneously realizing color nanoprinting and color holography on a metasurface according to claim 1, characterized in that, The design distance z is 1000μm.

9. A metasurface, characterized in that, The metasurface is designed using the method described in any one of claims 1 to 8 to simultaneously achieve color nanoprinting and color holography, and stores color nanoprinted images and color holographic images on it; when unpolarized white light is incident on the metasurface, the reflected light forms the color nanoprinted image on the metasurface after passing through the metasurface; using a wavelength of , , Circularly polarized light is incident on the metasurface to display the color holographic image on a designed distance plane.

Images