阅读说明：本技术 基于叠层超表面实现双通道纳米印刷和双通道全息的方法 (Method for realizing double-channel nano printing and double-channel holography based on laminated super surface ) 是由 李子乐 郑国兴 邓娟 单欣 李仲阳 于 2019-11-22 设计创作，主要内容包括：本发明涉及一种基于叠层超表面实现双通道纳米印刷和双通道全息的方法,包括：构建超表面单元结构,超表面单元结构包括基底、设置在基底上的第一纳米砖以及嵌于基底中的第二纳米砖；优化得到第一纳米砖和第二纳米砖的结构参数；构建超表面结构阵列,其包括多个超表面单元结构；根据入射光先后经过第一纳米砖和第二纳米砖以及先入射至第二纳米砖再入射到第一纳米砖两种模式下的近场图案和远场图案的成像要求,从中找出能同时满足近场成像的强度分布又在远场能形成相位型傅里叶全息图的第一纳米砖转向角θ<Sub>1</Sub>和第二纳米砖转向角θ<Sub>2</Sub>的排布,获得能实现双通道纳米印刷和双通道全息的超表面材料。本发明可以在一片超表面材料上编码四幅完全无关的图像。(The invention relates to a method for realizing double-channel nano printing and double-channel holography based on a laminated super surface, which comprises the following steps: constructing a super-surface unit structure, wherein the super-surface unit structure comprises a substrate, a first nano brick arranged on the substrate and a second nano brick embedded in the substrate; optimizing to obtain the structural parameters of the first nano brick and the second nano brick; constructing a super surface structure array which comprises a plurality of super surface unit structures; according to the imaging requirements of the incident light in two modes of passing through the first nano brick and the second nano brick in sequence and entering the first nano brick after entering the second nano brick, finding out a first nano brick steering angle theta which can meet the intensity distribution of near field imaging and can form a phase type Fourier hologram in a far field at the same time 1 And a second nano-brick steering angle theta 2 The metamaterial can realize double-channel nano printing and double-channel holography.The present invention can encode four completely unrelated images on a sheet of metamaterial.)

1. A method for realizing double-channel nano printing and double-channel holography based on a laminated super surface is characterized by comprising the following steps:

constructing a super-surface unit structure, wherein the super-surface unit structure comprises a substrate, a first nano brick arranged on a first working surface of the substrate and a second nano brick embedded in the substrate, the first nano brick and the first working surface form a first nano brick unit structure, the second nano brick is deposited on a second working surface in the substrate, the second nano brick and the second working surface form a second nano brick unit structure, the first nano brick unit structure and the second nano brick unit structure are correspondingly arranged, directions parallel to two edges of the first working surface of the substrate are respectively set as an x axis and a y axis to establish an xoy coordinate system, and a long axis L is arranged on a surface parallel to the first working surface of the first nano brick₁And minor axis W₁The second nano brick has a long axis L on the surface parallel to the first working surface₂And minor axis W₂The first nano-brick steering angle theta₁Is the major axis L of the first nano-brick₁Included angle with the x-axis direction, and steering angle theta of the second nano brick₂Is the major axis L of the first nano-brick₂The included angle between the X-axis direction and the X-axis direction;

optimizing to obtain the structural parameters of the first nano brick unit structure and the second nano brick unit structure;

constructing a super-surface structure array comprising a plurality of said super-surface unitsStructure with strength of I₀With a polarization direction of α₁The linearly polarized light is sequentially incident to the first nano brick unit structure, the substrate and the second nano brick unit structure to obtain the transmission light intensity I under the working mode₁And the linearly polarized polarization direction α₁The first nano brick steering angle theta₁And a second nano-brick steering angle theta₂A first functional relationship therebetween; with an intensity of I₀With a polarization direction of α₂The linearly polarized light is sequentially incident to the second nano-brick unit structure, the substrate and the first nano-brick unit structure to obtain the transmission light intensity I under the working mode₂And the polarization direction α of the linearly polarized light₂The first nano brick steering angle theta₁And a second nano-brick steering angle theta₂A second functional relationship therebetween; designed with strength of I₀With a polarization direction of α₁The linearly polarized light is sequentially incident to the first nano brick unit structure, the substrate and the second nano brick unit structure, a first image is generated in the near field of the laminated super-surface structure array, and the intensity is designed to be I₀With a polarization direction of α₂The linearly polarized light is sequentially incident to the second nano-brick unit structure, the substrate and the first nano-brick unit structure to generate a second image in a near field of the super-surface structure array, and the first nano-brick steering angle theta with four degrees of freedom is obtained according to the light intensity distribution requirement of the first image and the second image and the non-monotonicity contained in the first functional relation and the second functional relation₁And the second nano-brick steering angle theta₂(ii) a Then, circularly polarized light is designed to be sequentially incident to the first nano brick unit structure, the substrate and the second nano brick unit structure to generate a third image in a far field of the super-surface structure array, circularly polarized light is designed to be sequentially incident to the second nano brick unit structure, the substrate and the first nano brick unit structure to generate a fourth image in the far field of the super-surface structure array, and the first nano brick steering angle theta of four degrees of freedom is obtained according to the phase distribution requirements of the third image and the fourth image, the Jones matrix formula and the obtained first nano brick steering angle theta₁And the said firstSteering angle theta of two-nanometer brick₂Calculating and solving the steering angle theta of the first nano brick in each super surface unit structure in the super surface structure array₁Value and said second nano-brick steering angle theta₂Finally, the first nano brick and the second nano brick on each super-surface unit structure in the super-surface structure array are pressed according to the obtained steering angle theta of the first nano brick corresponding to each position₁Value and said second nano-brick steering angle theta₂The values are arranged to obtain a metamaterial capable of producing a two-channel nano-print and a two-channel hologram.

2. The method for performing dual channel nanoimprinting and dual channel holography based on a laminated super surface of claim 1 wherein the optimization yields structural parameters for a first nanoblock cell structure that is functionally equivalent to a polarizer at the operating wavelength of incidence and the optimization yields structural parameters for a second nanoblock cell structure that is functionally equivalent to a half-wave plate at the operating wavelength of incidence.

3. The method for dual channel nanoimprinting and dual channel holography based on a laminated metasurface of claim 2,

the method for obtaining the structure parameters of the first nano brick unit structure through optimization comprises the following steps: the method comprises the steps of scanning a first nano-brick unit structure under a working wavelength by taking the linear polarized light with the polarization direction along the long axis of a first nano-brick as an optimization target, reflecting the linear polarized light with the polarization direction along the short axis of the first nano-brick and transmitting the linear polarized light with the polarization direction along the short axis of the first nano-brick as an optimization target, and obtaining structural parameters of the first nano-brick unit structure required by the target through electromagnetic simulation optimization

The method for obtaining the structural parameters of the second nano-brick unit structure through optimization comprises the following steps: and vertically irradiating circularly polarized light with a working wavelength into the second nano brick unit structure, scanning the second nano brick unit structure at the working wavelength, and obtaining the structural parameters of the second nano brick unit structure required by the target through electromagnetic simulation optimization, wherein the transmission cross polarization efficiency of the incident circularly polarized light is not lower than 80% and the transmission co-polarization efficiency is not higher than 1%.

4. The method for dual channel nanoimprinting and dual channel holography based on a laminated super surface of any of claims 1-3, wherein the structural parameter of the first nano-tile cell structure comprises the long axis L of the first nano-tile₁Minor axis W₁And high H₁And the first working face side length C₁The structural parameter of the second nano-brick unit structure comprises the long axis L of the second nano-brick₂Minor axis W₂And high H₂And the second working face side length C₂The size of (c).

5. The method for performing dual channel nanoimprinting and dual channel holography based on a laminated metasurface of claim 2 wherein the emergent intensity is₁The first functional relationship of (a) is: i is₁＝I₀sin²(θ₁-α₁)；

Intensity of emergent light I₂The second function relationship of (2) is: i is₂＝I₀sin²(2θ₂-θ₁-α₂)。

6. The method for performing two-pass nanoimprinting and two-pass holography based on a laminated metasurface of claim 2, wherein the first nanoblock of four degrees of freedom has a turning angle θ₁，π/2-θ₁，π/2+θ₁，π-θ₁The turning angle of the second nano brick with four degrees of freedom is theta₂，π/2-θ₂，π/2+θ₂，π-θ₂。

7. The method of claim 1, wherein the substrate comprises a first substrate and a second substrate attached to the first substrate, the second nanobrick is embedded in the first substrate, the first working surface is a surface of the first substrate facing away from the second substrate, and the second working surface is a surface of the second substrate in contact with the first substrate.

8. The method for dual channel nanoimprinting and dual channel holography based on a laminated super surface of claim 1 wherein the substrate is made of fused silica glass material, the first nanoblock is made of silver material, and the second nanoblock is made of silicon material.

9. A metamaterial material designed based on the method of laminated metamaterial for dual channel nanoimprinting and dual channel holography as claimed in any of claims 1-8.

Technical Field

The invention relates to the technical field of micro-nano optics and image display, in particular to a method for realizing double-channel nano printing and double-channel holography based on a laminated super surface.

Background

The super-surface consisting of ultra-thin sub-wave antennas provides a method for implementing planar optical devices. Currently, super-surfaces are widely used in the fields of lenses, holograms, optical stealth, and the like. Compared with traditional optics, the super-surface has the obvious characteristic of realizing multifunctionality. The multifunctional super-surface generates different images by changing the polarization state, incidence angle and wavelength of incident light. However, the existing method cannot realize that two nano-printing images and two holographic images are simultaneously encoded on the same chip.

Disclosure of Invention

The invention aims to provide a method for realizing double-channel nano printing and double-channel holography based on a laminated super surface, and the super surface material prepared by the method can encode 4 totally unrelated images on one piece of super surface material. The invention is a new information multiplexing method, which can greatly enhance the information capacity and has great application prospect in the fields of image display, optical storage, anti-counterfeiting and the like.

The scheme adopted by the invention for solving the technical problems is as follows:

a method for realizing double-channel nano printing and double-channel holography based on a laminated super surface comprises the following steps:

constructing a super-surface unit structure, wherein the super-surface unit structure comprises a substrate, a first nano brick arranged on a first working surface of the substrate and a second nano brick embedded in the substrate, the first nano brick and the first working surface form a first nano brick unit structure, the second nano brick is deposited on a second working surface in the substrate, the second nano brick and the second working surface form a second nano brick unit structure, and the first nano brick unit structure and the second nano brick unit structure are correspondingly arranged so as to be respectively set as an x axis and a y axis in directions parallel to two edges of the first working surface of the substrateAn axis establishing xoy coordinate system, and a long axis L on the surface parallel to the first working surface of the first nano-brick₁And minor axis W₁The second nano brick has a long axis L on the surface parallel to the first working surface₂And minor axis W₂The first nano-brick steering angle theta₁Is the major axis L of the first nano-brick₁Included angle with the x-axis direction, and steering angle theta of the second nano brick₂Is the major axis L of the first nano-brick₂The included angle between the X-axis direction and the X-axis direction;

optimizing to obtain the structural parameters of the first nano brick unit structure and the second nano brick unit structure;

constructing a super-surface structure array, wherein the super-surface structure array comprises a plurality of super-surface unit structures with the strength of I₀With a polarization direction of α₁The linearly polarized light is sequentially incident to the first nano brick unit structure, the substrate and the second nano brick unit structure to obtain the transmission light intensity I in the working mode₁And the linearly polarized polarization direction α₁The first nano brick steering angle theta₁And a second nano-brick steering angle theta₂A first functional relationship therebetween; with an intensity of I₀With a polarization direction of α₂The linearly polarized light is sequentially incident to the second nano-brick unit structure, the substrate and the first nano-brick unit structure to obtain the transmission light intensity I under the working mode₂And the polarization direction α of the linearly polarized light₂The first nano brick steering angle theta₁And a second nano-brick steering angle theta₂A second functional relationship therebetween; designed with strength of I₀With a polarization direction of α₁The linearly polarized light is sequentially incident to the first nano brick unit structure, the substrate and the second nano brick unit structure, a first image is generated in the near field of the laminated super-surface structure array, and the intensity is designed to be I₀With a polarization direction of α₂The linearly polarized light is sequentially incident to the second nano-brick unit structure, the substrate and the first nano-brick unit structure, a second image is generated in the near field of the super-surface structure array, and the light intensity is divided according to the light intensity of the first image and the light intensity of the second imageThe cloth requirement and the first functional relation and the second functional relation obtain the steering angle theta of the first nano brick with four degrees of freedom₁And the second nano-brick steering angle theta₂(ii) a Then, circularly polarized light is designed to be sequentially incident to the first nano brick unit structure, the substrate and the second nano brick unit structure to generate a third image in a far field of the super-surface structure array, circularly polarized light is designed to be sequentially incident to the second nano brick unit structure, the substrate and the first nano brick unit structure to generate a fourth image in the far field of the super-surface structure array, and the first nano brick steering angle theta of four degrees of freedom is obtained according to the phase distribution requirements of the third image and the fourth image, the Jones matrix formula and the obtained first nano brick steering angle theta₁And the second nano-brick steering angle theta₂Calculating and solving the steering angle theta of the first nano brick in each super surface unit structure in the super surface structure array₁Value and said second nano-brick steering angle theta₂Finally, the first nano brick and the second nano brick on each super-surface unit structure in the super-surface structure array are pressed according to the obtained steering angle theta of the first nano brick corresponding to each position₁Value and said second nano-brick steering angle theta₂The values are arranged to obtain a metamaterial capable of producing a two-channel nano-print and a two-channel hologram.

Further, the structural parameters of the first nano-brick unit structure which is functionally equivalent to the polarizer when the light enters with the working wavelength and the structural parameters of the second nano-brick unit structure which is functionally equivalent to the half-wave plate when the light enters with the working wavelength are obtained through optimization.

Further, the method for optimizing the structural parameters of the first nano-brick unit structure comprises the following steps: the method comprises the steps of scanning a first nano-brick unit structure under a working wavelength by taking the linear polarized light with the polarization direction along the long axis of a first nano-brick as an optimization target, reflecting the linear polarized light with the polarization direction along the short axis of the first nano-brick and transmitting the linear polarized light with the polarization direction along the short axis of the first nano-brick as an optimization target, and obtaining structural parameters of the first nano-brick unit structure required by the target through electromagnetic simulation optimization

The method for obtaining the structural parameters of the second nano-brick unit structure through optimization comprises the following steps: and vertically irradiating circularly polarized light with a working wavelength into the second nano brick unit structure, scanning the second nano brick unit structure at the working wavelength, and obtaining the structural parameters of the second nano brick unit structure required by the target through electromagnetic simulation optimization, wherein the transmission cross polarization efficiency of the incident circularly polarized light is not lower than 80% and the transmission co-polarization efficiency is not higher than 1%.

Further, the structural parameter of the first nano-brick unit structure includes a long axis L of the first nano-brick₁Minor axis W₁And high H₁And the first working face side length C₁The structural parameter of the second nano-brick unit structure comprises the long axis L of the second nano-brick₂Minor axis W₂And high H₂And the second working face side length C₂The size of (c).

Further, the emergent light intensity I₁The first functional relationship of (a) is: i is₁＝I₀sin²(θ₁-α₁)；

Intensity of emergent light I₂The second function relationship of (2) is: i is₂＝I₀sin²(2θ₂-θ₁-α₂)。

Further, the steering angle of the first nano-brick with four degrees of freedom is theta₁，π/2-θ₁，π/2+θ₁，π-θ₁The turning angle of the second nano brick with four degrees of freedom is theta₂，π/2-θ₂，π/2+θ₂，π-θ₂。

Further, the substrate comprises a first substrate and a second substrate connected with the first substrate, the second nano brick is embedded in the first substrate, the first working surface is a surface of the first substrate, which is far away from the second substrate, and the second working surface is a surface of the second substrate, which is in contact with the first substrate.

Further, the substrate is made of a fused silica glass material, the first nanoblock is made of a silver material, and the second nanoblock is made of a silicon material.

It is another object of the present invention to provide a metamaterial material designed according to the above method for dual channel nano-printing and dual channel holography based on laminated metamaterials.

Compared with the prior art, the invention has at least the following beneficial effects:

1) the method for realizing double-channel nano printing and double-channel holography based on the laminated super-surface structure can realize the coding of four completely unrelated images on one super-surface material, and has the advantages of flexible design, strong function and very wide application prospect;

2) the sizes of the nano brick unit structures are all sub-wavelength levels, so that the super surface designed by the invention has small volume, light weight and high integration, and is suitable for the development of miniaturization in the future.

3) The four images generated by the invention can be independently designed without influencing each other, can meet different design requirements, and provides a new method for information multiplexing.

Drawings

FIG. 1 is a schematic diagram illustrating the effect of an array of super-surface structures according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a super-surface unit structure according to an embodiment of the present invention;

FIG. 3 is a scanning diagram of the transmittance and reflectance of the nano-brick polarizer in the embodiment of the present invention;

FIG. 4 is a scanned graph of the transmittance and reflectance of the half-wave plate of the nano-brick in the embodiment of the present invention;

FIG. 5 is a drawing of a simultaneous nanoprint and hologram of an embodiment of the present invention in a first mode of operation;

FIG. 6 is a diagram of a simultaneous nanoprint and hologram of an embodiment of the present invention in a second mode of operation.

Detailed Description

The following examples are provided to further illustrate the present invention for better understanding, but the present invention is not limited to the following examples.

It is to be noted that the experimental methods described in the following embodiments are all conventional methods unless otherwise specified, and the reagents and materials, if not otherwise specified, are commercially available; in the description of the present invention, the terms "lateral", "longitudinal", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", and the like indicate orientations or positional relationships based on those shown in the drawings, merely for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention.

The invention provides a method for realizing double-channel nano printing and double-channel holography based on a laminated super surface, which comprises the following steps:

constructing a super-surface unit structure, wherein the super-surface unit structure comprises a substrate, a first nano brick arranged on a first working surface of the substrate and a second nano brick embedded in the substrate, the first nano brick and the first working surface form a first nano brick unit structure, the second nano brick is deposited on a second working surface in the substrate, the second nano brick and the second working surface form a second nano brick unit structure, the first nano brick unit structure and the second nano brick unit structure are correspondingly arranged, an x axis and a y axis are respectively arranged in the direction parallel to the two edges of the first working surface of the substrate to establish an xoy coordinate system, and a long axis L is arranged on the surface parallel to the first working surface of the first nano brick₁And minor axis W₁The second nanometer brick has a long axis L on the surface parallel to the first working surface₂And minor axis W₂First nano-brick steering angle theta₁Is the major axis L of the first nano-brick₁Included angle with the x-axis direction and steering angle theta of the second nano brick₂Is the major axis L of the first nano-brick₂The included angle between the X-axis direction and the X-axis direction;

optimizing to obtain the structural parameters of a first nano-brick unit structure which is functionally equivalent to a polarizer when the light enters with the working wavelength and optimizing to obtain the structural parameters of a second nano-brick unit structure which is functionally equivalent to a half-wave plate when the light enters with the working wavelength;

constructing a super-surface structure array, wherein the super-surface structure array comprises a plurality of super-surface unit structures with strength I₀With a polarization direction of α₁The linearly polarized light is sequentially incident into the first nano brick unit structure, the substrate and the second nano brick unit structure to obtain the transmission light intensity I under the working mode₁And linear polarization direction α₁The first nano brick steering angle theta₁And a second nano-brick steering angle theta₂A first functional relationship therebetween; with an intensity of I₀With a polarization direction of α₂The linearly polarized light is sequentially incident into the second nano brick unit structure, the substrate and the first nano brick unit structure to obtain the transmission light intensity I under the working mode₂With the polarization direction α of linearly polarized light₂The first nano brick steering angle theta₁And a second nano-brick steering angle theta₂A second functional relationship therebetween; designed with strength of I₀With a polarization direction of α₁The linearly polarized light is sequentially incident to a first nano brick unit structure, a substrate and a second nano brick unit structure, a first image is generated in the near field of the laminated super-surface structure array, and the intensity is designed to be I₀With a polarization direction of α₂The linearly polarized light sequentially enters a second nano-brick unit structure, a substrate and the first nano-brick unit structure, a second image is generated in the near field of the super-surface structure array, and a first nano-brick steering angle theta with four degrees of freedom is obtained according to the light intensity distribution requirements of the first image and the second image and the corresponding non-monotonicity contained in the first functional relation and the second functional relation₁And a second nano-brick steering angle theta₂(ii) a Then, circularly polarized light is designed to be sequentially incident into the first nano brick unit structure, the substrate and the second nano brick unit structure to generate a third image in a far field of the super-surface structure array, circularly polarized light is designed to be sequentially incident into the second nano brick unit structure, the substrate and the first nano brick unit structure to generate a fourth image in the far field of the super-surface structure array, and the first nano brick steering angle theta of four degrees of freedom is obtained according to the phase distribution requirements of the third image and the fourth image, the Jones matrix formula and the obtained first nano brick steering angle theta₁And a second nano-brick steering angle theta₂Calculating to obtain super surface structure arrayThe first nanoblock steering angle θ in each super-surface unit structure in a column₁Value and second nano-brick steering angle theta₂Finally, the first nano brick and the second nano brick on each super surface unit structure in the super surface structure array are pressed according to the obtained steering angle theta of the corresponding first nano brick at each position₁Value and second nano-brick steering angle theta₂The values are arranged to obtain a material capable of producing a two-channel nano-printing and a two-channel holographic metamaterial.

Based on the constructed laminated super-surface material, when incident light is incident to the super-surface material according to the sequence of firstly passing through the first nano-brick polarizer and then passing through the second nano-brick half-wave plate, two unrelated images can be formed in a near field and a far field. When the incident light firstly passes through the second nano-brick half-wave plate and then passes through the first nano-brick polarizer, the incident light is incident to the ultra-surface material, and other two unrelated images can be formed in a near field and a far field.

The invention will be described in more detail with reference to the embodiment, which includes a stacked structure array including a plurality of stacked unit structures, wherein a schematic structural diagram of the super surface structure array is shown in fig. 1, and a schematic structural diagram of the super surface unit structure is shown in fig. 2. As can be seen from fig. 2, the super surface unit structure includes a first substrate 2, a second substrate 4 connected to a bottom surface of the first substrate 2, a first nano-brick 1 deposited on a top surface of the first substrate 2, and a second nano-brick 3 embedded in the first substrate 2 and deposited on a top surface of the second substrate 4. Wherein, the first nano brick 1 and the top surface of the first substrate 2 form a first nano brick unit structure, and the second nano brick 3 and the top surface of the second substrate 4 form a second nano brick unit structure. First nanometer brick 1 and second nanometer brick 3 on the same super surface unit structure correspond the setting, and the size and the central interval of first nanometer brick 1 on two adjacent first nanometer brick unit structures are all the same, and the size and the central interval of second nanometer brick 3 on two adjacent second nanometer brick unit structures are also all the same. Wherein the first substrate 2 and the second substrate 4 are both made of fused silica glass material, the first nanoblock 1 is made of silver material, and the second nanoblock 3 is made of silicon material. To be parallel to the first baseThe directions of two edges of the top surface of the bottom 2 are respectively set as an x axis and a y axis to establish an xoy coordinate system, and the surface of the first nano brick parallel to the top surface of the first substrate 2 is provided with a long axis L₁And minor axis W₁The second nano-brick 3 has a long axis L₂And minor axis W₂The major axis L of the first nano-brick 1₁The included angle between the first nano brick and the x-axis direction is a first nano brick steering angle theta₁The major axis L of the second nano-brick 3₂The included angle between the first nano brick and the x-axis direction is a second nano brick steering angle theta₂。

In order to realize the double-channel nano printing and the double-channel holography, the structural parameters of the unit structure of the first nano brick can be optimized, so that the function of the unit structure is equivalent to a transmission polarizer when the working wavelength is incident to the first nano brick, namely, linearly polarized light with the polarization direction along the long axis of the first nano brick is reflected, and linearly polarized light with the polarization direction along the short axis of the first nano brick is transmitted. And optimizing the structural parameters of the second nano-brick unit structure to ensure that the function of the second nano-brick unit structure is equivalent to a transmission type half-wave plate when the working wavelength is incident to the second nano-brick, namely all incident circularly polarized light is converted into transmission light with opposite rotation directions.

Taking the working wavelength λ as 633nm as an example, modeling and simulating by using electromagnetic simulation software, and optimizing the structural parameters of the obtained first nano-brick polarizer unit structure by using linearly polarized light along the major axis and minor axis of the first nano-brick as the vertical incidence of the first nano-brick unit structure, and using the light reflection efficiency along the major axis of the first nano-brick as the highest and the light transmission efficiency along the minor axis of the first nano-brick as the highest: major axis L₁160nm minor axis W₁80nm, high H₁70nm and a working face side length C of 300 nm. Under the structural parameters, the reflection and transmission efficiency of the first nano-brick unit structure to the linearly polarized light with two orthogonal polarization states vibrating along the major axis direction and the minor axis direction of the first nano-brick unit structure are shown in fig. 3, wherein Rx and Ty represent the reflectivity of the linearly polarized light vibrating along the major axis direction and the transmittance of the linearly polarized light vibrating along the minor axis direction of the first nano-brick unit structure, respectively, and Ry and Tx represent the reflectivity of the linearly polarized light vibrating along the minor axis direction and the transmittance of the linearly polarized light vibrating along the major axis direction of the first nano-brick unit structure, respectively. As can be seen from FIG. 3, at incident light wavelengths between 600nm and 700nm, the values of Rx and Ty are relatively high and the values of Ry and Tx are relatively low. Especially at the working wavelength of 633nm, Ty is higher than 90%, Ry and Tx are lower than 5%, indicating that the optimized first nanoblock unit structure can be equivalent to the function of a polarizer.

In addition, taking the working wavelength λ as 633nm as an example, modeling and simulating by using electromagnetic simulation software, vertically irradiating the second nano-brick unit structure with circularly polarized light, and scanning the structural parameters of the second nano-brick unit structure at the working wavelength, including L₂、W₂、H₂、C₂The optimization aims to be high in transmission cross polarization efficiency and low in transmission co-polarization efficiency. The structural parameters of the second and nano-brick unit structure are preferably: major axis L₂170nm, minor axis W₂80nm, high H₂380nm and 300nm of working face side length C. Under the structural parameters, the transmission co-polarization conversion efficiency and the transmission counter-polarization conversion efficiency of the second nano-brick unit structure are shown in fig. 4. Where T _ cross is the transmission reverse polarization conversion efficiency, T _ co is the transmission co-polarization conversion efficiency, R _ cross is the reflection reverse polarization conversion efficiency, and R _ co is the reflection co-polarization conversion efficiency. As can be seen from fig. 4, at 633nm of the operating wavelength, T _ cross is higher than 95%, and T _ co, R _ cross are all lower than 3%, indicating that the optimized second nanoblock unit structure can be equivalent to the function of a transmissive half-wave plate.

After the structural parameters of the optimized first nano brick unit structure and the optimized second nano brick unit structure are obtained, the strength is taken as I₀With a polarization direction of α₁The linearly polarized light is sequentially incident to the first nano-brick polarizer unit and the second nano-brick half-wave plate unit, and the transmission light intensity is described by the following formula:

i.e. the intensity of the transmitted light is I₁＝I₀sin²(θ₁-α₁)

With a strength ofI₀With a polarization direction of α₂The linearly polarized light is sequentially incident into the second nano-brick half-wave plate unit structure and the first nano-brick polarizer unit structure, and the transmission light intensity is described by the following formula:

i.e. transmitted light intensity I₂＝I₀sin²(2θ₂-θ₁-α₂)。

Establishing a simultaneous formula of the first function formula and the second function formula according to the obtained first function formula and the second function formula

The simultaneous formula shows that the linear polarization (α) is constant for a certain incident light₁、α₂And I₀A fixed value), the steering angle theta of the first nano brick can be adjusted by adjusting₁And a second nano-brick steering angle theta₂Obtain arbitrary emergent light intensity I₁、I₂Due to theta₁And theta₂The images generated under the two working modes are completely independent and independent from each other and can be independently designed. In addition, due to the trigonometric function sin²Theta is a non-monotonic function, so that the turning angle between the first and second nanobubbles is 0 deg., 180 deg]Within the range of (1), all have a turning angle of 4 degrees of freedom, i.e. when the turning angle of the first nano-brick is theta₁，π/2-θ₁，π/2+θ₁，π-θ₁All generate the same emergent light intensity I₁(ii) a When the steering angle of the second nano-brick is theta₂，π/2-θ₂，π/2+θ₂，π-θ₂All generate the same emergent light intensity I₂。

Designed with strength of I₀With a polarization direction of α₁The linearly polarized light is sequentially incident to a first nano brick unit structure, a first substrate and a second nano brick unit structure, a first target nano printing pattern is generated in the near field of the super-surface structure array, and the intensity is designed to be I₀With a polarization direction of α₂Linearly polarized light enters in sequenceA second target nano-brick printing pattern is generated in the near field of the super-surface structure array by irradiating the second nano-brick unit structure, the first substrate and the first nano-brick unit structure, and four first nano-brick steering angles theta of each first nano-brick unit structure are obtained according to the light intensity distribution requirements of the first target nano-brick printing pattern and the second target nano-brick printing pattern and the simultaneous formula₁And four second nano-brick steering angles theta of each second nano-brick unit structure₂. If the size of the nano-printed image is M x M and each nano-brick corresponds to one pixel, the total number of the nano-printed image is 4^M*MThe seed nanoblock turning angle combination may generate a target nanoimprinted image.

Then, circularly polarized light is designed to be sequentially incident to the first nano brick unit structure, the first substrate and the second nano brick unit structure to generate a first target holographic pattern in a far field of the super-surface structure array, and circularly polarized light is designed to be sequentially incident to the second nano brick unit structure, the first substrate and the first nano brick unit structure to generate a second target holographic pattern in the far field of the super-surface structure array.

When circularly polarized light is incident to the anisotropic nano brick structure, the Jones matrix formula of emergent light is as follows:

where θ is the turning angle of the nanoblock, and a and B are the transmission or reflection coefficients in the major and minor axis directions when linearly polarized light along the major and minor axis directions is incident. Wherein q and p are:

from the above formula, after the circularly polarized light passes through the nano-brick, the output field is divided into two parts, one part is circularly polarized light with the same handedness as the incident light, the other part is circularly polarized light with the opposite handedness as the incident light, and the modes of p and q represent the amplitudes of the two parts of circularly polarized light respectively. Analysis shows that only with the anisotropy of the optical element (a ≠ B), the output light field always contains reversed circularly polarized light, and the absolute value of the phase modulation amount of the reversed circularly polarized light is equal to twice the rotation angle of the optical element. This is the adjusting mechanism of the geometric phase, and the phase change quantity only has a relation with the rotation angle of the nano brick.

According to the phase distribution requirements of the first target holographic pattern and the second target holographic pattern to be generated, the Jones matrix formula and the four obtained first nano-brick steering angles theta₁And four second nano-brick steering angles theta₂Calculating and solving the steering angle theta of the first nano brick in each super-surface unit structure in the super-surface structure array by means of optimization algorithms such as simulated annealing optimization algorithm and the like₁Value and said second nano-brick steering angle theta₂Finally, the first nano brick and the second nano brick on each super surface unit structure in the super surface structure array are subjected to the corresponding first nano brick steering angle theta according to the obtained positions₁Value and second nano-brick steering angle theta₂The values are arranged to obtain a metamaterial capable of producing a two-channel nanomrint and a two-channel hologram, the metamaterial simultaneously satisfying an intensity distribution for near-field imaging while forming a phase-type Fourier hologram in a far field.

Based on the constructed laminated metamaterial with strength I₀With a polarization direction of α₁The linearly polarized light firstly passes through the first nano-brick polarizer and then passes through the second nano-brick half-wave plate, and is incident to the ultra-surface material, so that a first nano-printed pattern can be formed in a near field; when circularly polarized light is incident to the metamaterial in the order of first passing through the first nanoblock polarizer and then the second nanoblock half-wave plate, a first holographic pattern can be formed in the far field, as shown in fig. 5. When the intensity is I₀With a polarization direction of α₂The linearly polarized light firstly passes through the second nano brick half-wave plate and then enters the ultra-surface material in the sequence of the first nano brick polarizer, and a second nano printing pattern can be formed in a near field; when circularly polarized light passes through the second nanometer firstThe tile half-wave plate passes through the sequence of the first nano-tile polarizer, and the incident light to the metamaterial can form a second holographic pattern in a far field, as shown in fig. 6.

While the foregoing is directed to the preferred embodiment of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.