CN116719105A - Optical super-structured surface device and design method and manufacturing method thereof - Google Patents

Abstract

A method of designing an optical super-structured surface device comprising a substrate and a plurality of super-structured structural units periodically arranged on the substrate, the method comprising: acquiring a unit pattern representing a corresponding super-structure unit, the unit pattern comprising a pixel array having a plurality of pixels, each pixel having a first state or a second state; in response to determining that the transmissive property of the super-structure unit does not meet the preset condition, performing the following operations in a loop: determining weights of the pixels; randomly flipping the state of one or more pixels of a group of pixels based on the weights to obtain a current cell pattern; and selectively maintaining the respective states of the plurality of pixels or restoring the state of the group of one or more pixels to the state before the inversion based on the optical simulation of the super-structured unit represented by the current unit pattern; in response to determining that the transmissive properties of the superstructured unit meet a preset condition, descriptive information defining the optical superstructured surface device is generated.

Description

Optical super-structured surface device and design method and manufacturing method thereof

Technical Field

The present disclosure relates to the field of optical technology, and in particular, to an optical super-structured surface device, and a design method and a manufacturing method thereof.

Background

The optical super-structured surface is a novel material which is designed manually and realizes the super-normal characteristic and has the optical characteristic which is not found in the natural material. The super-structured surface can shape the wavefront, polarization, transmission performance and nonlinear response of light in different modes, has unique capability in the aspect of light regulation and control capability, and provides a brand new platform for microminiaturization and high-performance micro-nano optical device design.

Optical devices that achieve specific manipulation of light (e.g., unidirectional transmission, unidirectional reflection) have wide ranging applications in a variety of technical fields. In the related art, such an optical device is complicated in design and large in size, which is disadvantageous for integration.

Disclosure of Invention

It would be advantageous to provide a mechanism that alleviates, mitigates or even eliminates one or more of the above problems.

According to an aspect of the present disclosure, there is provided a method of designing an optical super-structured surface device, the optical super-structured surface device comprising a substrate and a plurality of super-structured structural units periodically arranged on the substrate, the method comprising: obtaining a unit pattern representing a corresponding super-structure unit in a plurality of super-structure units, wherein the unit pattern comprises a pixel array with a plurality of pixels, each pixel in the plurality of pixels has a first state or a second state, the first state represents that super-structure material exists in a position corresponding to the pixel in the super-structure unit, and the second state represents that super-structure material does not exist in the position corresponding to the pixel in the super-structure unit; based on optical simulation of the super-structure unit, determining that the transmission performance of the super-structure unit does not meet a preset condition; in response to determining that the transmissive property of the super-structure unit does not meet the preset condition, performing the following operations in a loop: determining weights of the pixels; randomly flipping the state of one or more pixels of a group of pixels based on the weights to obtain a current cell pattern; and selectively maintaining the respective states of the plurality of pixels or restoring the state of the group of one or more pixels to the state before the inversion based on the optical simulation of the super-structured unit represented by the current unit pattern; and generating descriptive information defining the optical superstructured surface device in response to determining that the transmissive properties of the superstructured structural unit meet the preset condition.

According to another aspect of the present disclosure, there is provided a method of manufacturing an optical super-structured surface device, comprising: using the description information generated in the method as described above, a plurality of super-structure units are formed on a substrate.

According to another aspect of the present disclosure, there is provided an optical super-structured surface device, manufactured using the method as described above.

These and other aspects of the disclosure will be apparent from and elucidated with reference to the embodiments described hereinafter.

Drawings

Further details, features and advantages of the present disclosure are disclosed in the following description of exemplary embodiments, with reference to the following drawings, wherein:

FIG. 1 is a flow chart of a method of designing an optical super-structured surface device according to an exemplary embodiment of the present disclosure;

FIG. 2 is a schematic view of a cell pattern representing a super-structure cell in accordance with an exemplary embodiment of the present disclosure;

fig. 3 is a schematic view of an optical super-structured surface device according to an exemplary embodiment of the present disclosure.

FIG. 4 is a flow chart of a method of designing an optical super-structured surface device according to another exemplary embodiment of the present disclosure;

FIG. 5 is a schematic view representing Laplacian values for pixels according to an exemplary embodiment of the present disclosure;

FIG. 6 is a schematic view of representing Laplacian values for pixels after multiple iterative optimization according to an exemplary embodiment of the present disclosure;

FIG. 7 is a schematic view of the transmission performance of a super-structure unit after multiple iterative optimization in accordance with an exemplary embodiment of the present disclosure;

FIG. 8 is a schematic view of a super-structure cell and its transmissive properties in the case of linear polarized incidence according to an exemplary embodiment of the present disclosure;

FIG. 9A is a schematic view of a symmetry-extended super-structure unit according to an exemplary embodiment of the present disclosure;

FIG. 9B is a schematic view of a machined optical superstructured surface device of symmetrically expanded superstructured structural units according to an exemplary embodiment of the present disclosure;

fig. 9C is a schematic view of the transmission performance of an optical super-structured surface device according to an exemplary embodiment of the present disclosure.

Detailed Description

It will be understood that, although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present disclosure.

Spatially relative terms, such as "under …," "under …," "lower," "under …," "over …," "upper," and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that these spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "under" or "beneath" other elements or features would then be oriented "over" the other elements or features. Thus, the exemplary terms "below …" and "below …" may encompass both orientations above … and below …. Terms such as "before …" or "before …" and "after …" or "followed by" may similarly be used, for example, to indicate the order in which light passes through the elements. The device may be oriented in other ways (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. In addition, it will also be understood that when a layer is referred to as being "between" two layers, it can be the only layer between the two layers, or one or more intervening layers may also be present.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items, and the phrase "at least one of a and B" means a alone, B alone, or both a and B.

It will be understood that when an element or layer is referred to as being "on," "connected to," "coupled to," or "adjacent to" another element or layer, it can be directly on, connected to, coupled to, or adjacent to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on," "directly connected to," "directly coupled to," or "directly adjacent to" another element or layer, there are no intervening elements or layers present. However, in no event "on …" or "directly on …" should be construed as requiring one layer to completely cover an underlying layer.

Embodiments of the present disclosure are described herein with reference to schematic illustrations (and intermediate structures) of idealized embodiments of the present disclosure. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, embodiments of the present disclosure should not be construed as limited to the particular shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. Thus, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the actual shape of a region of a device and are not intended to limit the scope of the present disclosure.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and/or the present specification and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

As used herein, the term "substrate" may refer to a substrate of a diced wafer, or may refer to a substrate of an uncut wafer. Similarly, the terms chip and die (die) may be used interchangeably unless such interchange would cause a conflict. It should be understood that the term "layer" includes films and should not be construed to indicate vertical or horizontal thickness unless otherwise indicated.

The special spatial light-transmitting property of unidirectional transmission and unidirectional reflection is combined with the ultra-thin portable device integration capability, and can be used for occasions such as under-screen fingerprint identification, screen panels, cameras and the like.

In the related art, most of the unidirectional transparent and unidirectional reflecting super-structured materials are metal and dielectric material multiplexing systems, and 3D processing technology is needed. In the technology related to unidirectional transmission, the reflector is limited to be realized by using a multi-layer Bragg structure, and the thickness of the reflector is high, so that the integration is not facilitated. In addition, unidirectional transmission systems based on silicon (Si) dielectric materials operate in the infrared band.

The device of the related art, which transmits unidirectionally and has high isolation, filters light based on magneto-optical effect and a polarizing plate, and transmits only linearly polarized light. In addition, although the optical isolator based on the magneto-optical effect can realize extremely high isolation rate, the combined thickness of the magneto-optical crystal and the polaroid is millimeter magnitude, and the optical isolator can only be used in a system light path, so that the integration of portable equipment is difficult to realize.

In the related art, a metal is introduced into a metal-medium composite system, so that light forms local hot spots near the metal in reverse transmission, and strong absorption is realized. Because noble metal Au is cited, electron Beam Lithography (EBL) processing or gray scale lithography is needed, the mass production processing difficulty is high, and the cost is high. In addition, the introduction of the metal material can cause the increase of optical transmission loss, which is unfavorable for the optimization of the performance of the device. Meanwhile, light irradiates metal in normal incidence, absorption is caused, loss is high, and isolation is low (80% -20%). If a unidirectional transmission device is required to be designed in an all-dielectric material system, the reverse transmittance is difficult to inhibit because the absorption loss in a metal system cannot be utilized, and the difficulty in geometric selection of a material system and a structure is high.

Fig. 1 is a flow chart of a method 100 of designing an optical super-structured surface device according to an exemplary embodiment of the present disclosure. An optical superstructured surface device includes a substrate and a plurality of superstructured structural units periodically arranged on the substrate. As shown in FIG. 1, design method 100 includes steps 110-140.

At step 110, a cell pattern representing a respective one of a plurality of super-structure cells is obtained, the cell pattern comprising a pixel array having a plurality of pixels, each of the plurality of pixels having a first state representing the presence of super-structure material in a position of the super-structure cell corresponding to the pixel or a second state representing the absence of super-structure material in the position of the super-structure cell corresponding to the pixel. In some exemplary embodiments, the refractive index of the metamaterial is greater than the refractive index of the substrate.

In step 120, it is determined that the transmittance properties of the super-structure unit do not satisfy the preset condition based on the optical simulation of the super-structure unit.

Next, in response to determining that the transmittance properties of the super-structure unit do not satisfy the preset conditions, steps 130-1 to 130-3 are cyclically performed. In step 130-1, the weights for each of the plurality of pixels are determined. At step 130-2, based on the weights, the states of a set of one or more pixels of the plurality of pixels are randomly flipped to obtain the current cell pattern. At step 130-3, the state of each of the plurality of pixels is selectively maintained or the state of the group of one or more pixels is restored to the state prior to the flip based on the optical simulation of the super-structure cell represented by the current cell pattern.

In step 140, descriptive information defining the optical superstructured surface device is generated in response to determining that the transmissive properties of the superstructured structural unit meet a preset condition.

In some exemplary embodiments, a plurality of super-structure units are formed on a substrate using the description information generated in design method 100 to fabricate an optical super-structure surface device. In one example, the descriptive information may be a Process Design Kit (PDK) or a portion of a process design kit.

In summary, the design method 100 uses an optimization algorithm to optimally design the pixel array representing the metamaterial. The optical super-structured surface device can be manufactured according to the description information of the optical super-structured surface device generated by the design method 100. In some embodiments, the resulting optical superstructured surface device may meet the performance requirements of unidirectional transmission. Further, in some embodiments, the substrate and the superstructured structural units of the optical superstructured surface device do not include metallic materials, thereby enabling unidirectional transmission with pure dielectric materials.

In some exemplary embodiments, determining the weights for each of the plurality of pixels (step 130-1) includes: calculating a Laplacian matrix corresponding to the pixel array; and assigning weights of the pixels according to the Laplace values of the pixels in the Laplace matrix, wherein the Laplace values correspond to the pixels, and the weights of the pixels are positively correlated with the Laplace values of the pixels.

In some exemplary embodiments, randomly toggling the state of a group of one or more pixels of the plurality of pixels (step 130-2) includes: selecting a set of one or more pixels from a plurality of pixels according to the weight, wherein the probability of each pixel in the plurality of pixels being selected is positively correlated with the weight of the pixel; and flipping the state of a group of one or more pixels.

In some exemplary embodiments, selectively maintaining the state of each of the plurality of pixels or restoring the state of a group of one or more pixels to the state prior to inversion (step 130-3) includes: maintaining the respective states of the plurality of pixels in response to determining that the transmissive performance of the super-structure unit represented by the current unit pattern is higher than the transmissive performance of the super-structure unit prior to flipping; and in response to determining that the transmissive property of the superconstructed structural unit represented by the current unit pattern is not higher than the transmissive property of the superconstructed structural unit prior to flipping, restoring the state of the group of one or more pixels to the state prior to flipping.

Fig. 2 is a schematic view of a cell pattern 200 representing a super-structure cell according to an exemplary embodiment of the present disclosure. As shown in fig. 2, the unit pattern 200 includes a pixel array having a plurality of pixels. Wherein each pixel has a first state (shown in dark in fig. 2) or a second state (shown in light in fig. 2). For example, the pixel 210 has a first state indicating that the super-structure material is processed at a position corresponding to the pixel 210 in the super-structure unit. The pixel 220 has a second state that indicates that there is no metamaterial in the super-structure unit at a position corresponding to the pixel 220. For example, the position in the super-structure unit corresponding to the pixel 220 is air. In some exemplary embodiments, the cell pattern 200 may be generated through complete randomization.

In some exemplary embodiments, the unit pattern 200 includes 10×10 to 40×40 pixels.

In some exemplary embodiments, the optical superstructured surface device is fabricated by forming a plurality of superstructured structural units on a substrate using the descriptive information generated in design method 100. Fig. 3 is a schematic view of an optical super-structured surface device 300 according to an exemplary embodiment of the present disclosure. The optical superstructured surface device 300 is fabricated by forming a plurality of superstructured structural units 310 on a substrate 320.

In some exemplary embodiments, each of the plurality of super-structure units 310 has a size ranging from 700nm by 700nm to 2000nm by 2000nm.

In some exemplary embodiments, the cell pattern of a respective super-structure cell of the plurality of super-structure cells includes 10×10 to 40×40 pixels, and the size of each pixel ranges from 20nm×20nm to 60nm×60nm.

In some exemplary embodiments, the material of the substrate 320 is glass and the material of the superstructural material 350 is silicon nitride (SiN).

In some exemplary embodiments, the thickness of the metamaterial 350 may be less than 1 μm, facilitating integration. For example, the thickness ranges from 100nm to 500nm.

In some exemplary embodiments, the minimum linewidth of the super structure unit 310 may be flexibly set to be optimized according to the processing conditions. The optical super-structure surface device 300 manufactured based on the design has low requirement on process sensitivity, can effectively control the excellent rate and realizes large-area processing.

In some exemplary embodiments, the transmission performance in method 100 is determined based on the transmission spectrum of the super-structure unit at normal incidence and the transmission spectrum of the super-structure unit at reverse incidence. Normal incidence means that the superstructural unit is incident from a side of the superstructural unit remote from the substrate, such as the direction of incidence 330 in fig. 3. Reverse incidence refers to incidence of the substrate from a side of the substrate remote from the superstructural unit, such as the direction of incidence 340.

In some exemplary embodiments, the preset conditions in method 100 include a transmittance of normal incidence greater than a first threshold and a transmittance of reverse incidence less than a second threshold. In some examples, the first threshold is greater than the second threshold.

The optical superstructured surface device 300 is fabricated by forming a plurality of superstructured cells on a substrate 320 according to the description information for designing the superstructured cells 310 using the method 100. By designing the super-structured unit 310, the optical super-structured surface device 300 is able to achieve that the incident transmittance reaches a preset condition at the time of forward incidence 330 and that the reverse incident transmittance reaches a preset condition at the time of reverse incidence 340. In some embodiments, optical superstructured surface device 300 may achieve unidirectional transmissive, unidirectional non-transmissive optical performance in an all-dielectric system.

In addition, unlike other gradient descent algorithms, the design methods described by embodiments of the present disclosure can support optimized structural designs of different shape features and promote performance optimization upper limits. This is because in the related art, the pixel optimization algorithm with high degree of freedom is generally based on heuristic learning, which has the disadvantages of low optimization efficiency, and can obtain the optimal solution by theoretically traversing all cases, but the pixel optimization algorithm needs to run a quite long iteration number, which is not acceptable in reality.

Fig. 4 is a flow chart of a method 400 of designing an optical super-structured surface device according to another exemplary embodiment of the present disclosure. Design method 400 is an example of design method 100. As shown in fig. 4, method 400 includes steps 410 through 480.

At step 410, a cell pattern, such as cell pattern 200, of a corresponding super-structure cell of the plurality of super-structure cells is randomly generated.

In step 420, a laplacian matrix of the pixel array included in the cell pattern is calculated.

In step 430, weights of the plurality of pixels are assigned according to the laplace values of the plurality of pixels in the laplace matrix, respectively, and states of the group of one or more pixels are randomly flipped. In some exemplary embodiments, the weights of the respective plurality of pixels are positively correlated with the respective corresponding laplace values of the plurality of pixels. For example, a pixel having a Laplace value of 0 may be assigned a weight of 0; pixels with a Laplace value of 1 may be assigned a weight of 1; pixels with a Laplace value of 2 may be assigned a weight of 2; pixels with a laplace value of 3 may be assigned a weight of 4; pixels with a laplace value of 4 may be assigned a weight of 8. After the weight is allocated to each pixel, the pixels with large weights are randomly selected according to the weight, and the probability of being selected is high. The selected pixel is flipped over the existing state. For example, a pixel having a first state will be flipped to a second state. Correspondingly, at the position corresponding to the pixel in the super-structure unit, the state with the super-structure material is inverted from the state without the super-structure material, such as air.

In some exemplary embodiments, the super-structure units may be symmetrically expanded at step 440 such that the plurality of super-structure units are arranged in a symmetrical expansion on the substrate. For example, the super-structure unit may be C4 symmetry extended. The super-structure unit with the C4 symmetry expanded coincides with the super-structure unit when rotated by any 90 degrees. The super-structured surface fabricated by the symmetry-extended super-structured unit is insensitive to the polarization state of incident light. In some embodiments, the super-structured surface has optical properties of unidirectional transmission, unidirectional reflection, whether the incident light polarization is linearly polarized or unpolarized.

At step 450, it is determined whether there is an improvement in the transmission performance of the inverted superconstructed structural unit based on the optical simulation of the superconstructed structural unit. In some exemplary embodiments, optical simulation may employ a time domain finite element difference method (FDTD). And calculating forward transmission spectrum and backward transmission spectrum under the forward and backward incidence conditions of the super-structure unit represented by the current unit pattern through FDTD, and calculating a reward function (transmission performance/unidirectional transmission performance) of the super-structure unit. If the transmittance of the super-structure unit is improved, the current unit pattern is reserved. Otherwise, at step 460, the state of the flipped pixel is restored to the state prior to flipping.

In step 470, it is determined whether the transmissive properties of the super-structure unit satisfy a preset condition. If the preset condition is satisfied, the iterative optimization process is ended, and in step 480, description information defining the optical super-structure surface device is generated. In one example, the description information may be a Process Design Kit (PDK). If the predetermined condition is not satisfied, the process returns to step 430, where the state of a group of one or more pixels is randomly flipped again according to the weights.

According to the description information of the optical super-structured surface device generated by the design method 400, the optical super-structured surface device meeting the predetermined performance requirement can be manufactured. Design method 400 performs a biased random selection, otherwise known as a laplace binary search, based on the laplace (laplace) matrix assigned weights. The design methodology 400 improves the efficiency of optimization over direct binary search methodologies that do not assign weights, i.e., have exactly the same probability of being selected.

Fig. 5 is a schematic view representing a laplace value for a pixel according to an exemplary embodiment of the present disclosure. As shown in fig. 5, the upper half 510 represents the pixel array corresponding to the super-structure unit, and the lower half 520 represents the laplace matrix calculated for each pixel array. For example, pixel 512 corresponds to a Laplace value of 4 (indicated by reference numeral 522).

Fig. 6 is a schematic view of representing the laplace value for a pixel after multiple iterative optimization in accordance with an exemplary embodiment of the present disclosure. In some exemplary embodiments, the iterative optimization method may be a method as described in method 100, method 400, or other embodiments. As shown in FIG. 6, 610 represents a cell pattern corresponding to the super-structure cells generated in each iteration in the multiple iterative optimization (i-vi). 620 represents the calculated laplacian matrix based on each unit pattern in a plurality of iterative optimizations. 630 represents the distribution of the laplace value with the corresponding number of pixels. In 630, the horizontal axis represents the laplace value, and the vertical axis represents the number of pixels. It can be seen that most of the pixels in the first few iterative optimizations have a large laplace value. The pixels selected for flipping are now nearly completely random. Since the Laplace value of the pixels located at the edges and the protruding positions of the super-structure unit is larger, the pixels at the edges and the protruding positions can be selected for flipping. Thus, as the number of iterative optimizations increases, a large number of pixels all have smaller Laplacian values. Meanwhile, most pixels are located inside the super-structure unit, and only a small amount is located at the edge of the super-structure unit.

Fig. 7 is a schematic view of the transmission performance of a super-structure unit after multiple iterative optimization in accordance with an exemplary embodiment of the present disclosure. As shown in fig. 7, the horizontal axis represents the number of iterations, and the vertical axis represents the transmission performance of the super-structure unit. The curve indicated at 710 represents the relationship between the number of iterations and transmission performance when using a laplace binary search of an embodiment of the present disclosure. The curve indicated by 720 represents the relationship between the number of iterations and the transmission performance when a direct binary search is employed. As can be seen from fig. 7, the optimization efficiency of the laplace binary search method described in the embodiments of the present disclosure is greatly improved relative to the direct binary search method. In some embodiments, difficult to machine linewidths may also be avoided.

In summary, the laplace binary search described in the embodiments of the present disclosure can dynamically allocate the weight of each pixel selected to be turned over according to the proximity relation of the pixels, can consider the diversity of the initial optimization iteration, and can converge to an acceptable optimal value at a faster speed. In addition, in the algorithm, the Laplace value corresponding to the independent pixel is larger, and the selected weight is higher, so that the existence of the independent pixel can be eliminated, and the occurrence of a line width which is difficult to process is avoided.

Fig. 8 is a schematic view of a super-structure cell and its transmissive properties in the case of linear polarized incidence according to an exemplary embodiment of the present disclosure. Under the condition of linear polarization incidence, the super-structure unit with the unidirectional transmission and unidirectional reflection functions can be obtained based on the method of the embodiment of the disclosure. As shown in fig. 8, 810 denotes the polarization direction of incident light. And 820 represents a cell pattern corresponding to the super-structure cells obtained through iterative optimization under the incident light. 830 shows the transmission performance for the super-structure unit shown in correspondence 820, where the horizontal axis shows the wavelength (nm) of the incident light and the vertical axis shows the transmittance. The curve indicated by 832 represents forward transmittance and the curve indicated by 834 represents reverse transmittance.

Fig. 9A is a schematic view of a symmetry-extended super-structure unit according to an exemplary embodiment of the present disclosure. In some exemplary embodiments, a plurality of super-structured units are arranged in a symmetrical spread on a substrate, resulting in a super-structured surface that is insensitive to polarized light. The 5 super-structure units shown in fig. 9A were each C4 symmetry extended. For example, the super-structure unit indicated at 910 is derived via C4 symmetry expansion via the super-structure unit generated as at iteration vi of 610 in FIG. 6.

Fig. 9B is a schematic view of a machined optical superstructured surface device of a symmetrically expanded superstructured structural unit according to an exemplary embodiment of the present disclosure. As shown in FIG. 9B, the C4 symmetry extended super structure unit 910 of FIG. 9A is selected for machining. For example, electron beam direct writing may be used for processing, resulting in a scanning electron microscope sample characterization as shown at 920. Through selecting a large number of potential structures, the structure meeting the minimum line width requirements under different processes can be obtained.

Fig. 9C is a schematic view of the transmission performance of an optical super-structured surface device according to an exemplary embodiment of the present disclosure. As shown in fig. 9C, the horizontal axis represents the wavelength (nm) of the incident light, and the vertical axis represents the transmittance of the experimentally processed optical super-structured surface device 920. In fig. 9C, the curve indicated by 930 represents the transmittance at normal incidence, and the curve indicated by 940 represents the transmittance at reverse incidence. Normal incidence refers to incidence from the metamaterial direction (e.g., direction 330 in fig. 3); reverse incidence refers to incidence from the substrate direction (e.g., direction 340 in fig. 3). It can be seen that the forward transmittance of optical super-structured surface device 920 is greater than 90%. When the bandwidth of the incident light is around 50nm, the reverse transmittance of the optical super-structured surface device 920 is around 10%. Meanwhile, when the bandwidth of the incident light is between 400nm and 560nm, the reverse transmittance of the optical super-structured surface device 920 is less than 40%. It should be understood that as used herein, the term one-way transmission refers to a transmission in one direction that is above a predetermined threshold (e.g., 90%, 85%, 80%, etc.), while a transmission in the opposite direction of 0 is not required.

While the disclosure has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative and schematic and not restrictive; the present disclosure is not limited to the disclosed embodiments. Variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed subject matter, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps than those listed and the indefinite article "a" or "an" does not exclude a plurality, and the term "plurality" means two or more. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

Claims (14)

1. A method of designing an optical super-structured surface device comprising a substrate and a plurality of super-structured structural units periodically arranged on the substrate, the method comprising:

obtaining a unit pattern representing a corresponding super-structure unit in the super-structure units, wherein the unit pattern comprises a pixel array with a plurality of pixels, each pixel in the plurality of pixels has a first state or a second state, the first state represents that super-structure material exists in a position corresponding to the pixel in the super-structure unit, and the second state represents that the super-structure material does not exist in the position corresponding to the pixel in the super-structure unit;

based on the optical simulation of the super-structure unit, determining that the transmission performance of the super-structure unit does not meet a preset condition;

in response to determining that the transmittance properties of the super-structure units do not meet a preset condition, performing the following operations in a loop:

determining weights of the pixels respectively;

randomly flipping the state of a group of one or more pixels of the plurality of pixels based on the weight to obtain a current cell pattern; and is also provided with

Selectively maintaining the respective states of the plurality of pixels or restoring the state of the group of one or more pixels to a pre-flip state based on an optical simulation of the super-structure cell represented by the current cell pattern; and

and generating descriptive information defining the optical super-structure surface device in response to determining that the transmission performance of the super-structure unit meets the preset condition.

2. The method of claim 1, wherein the randomly flipping the state of a group of one or more pixels of the plurality of pixels comprises:

selecting the set of one or more pixels from the plurality of pixels according to the weight, wherein the probability that each of the plurality of pixels is selected is positively correlated with the weight of the pixel; and

the state of the set of one or more pixels is flipped.

3. The method of claim 1, wherein the selectively maintaining the state of each of the plurality of pixels or restoring the state of the set of one or more pixels to the state prior to the flip comprises:

maintaining the respective states of the plurality of pixels in response to determining that the transmissive performance of the super-structure unit represented by the current unit pattern is higher than the transmissive performance of the super-structure unit prior to flipping; and

in response to determining that the transmissive property of the super-structure cell represented by the current cell pattern is not higher than the transmissive property of the super-structure cell prior to flipping, restoring the state of the set of one or more pixels to the state prior to flipping.

4. The method of claim 1, wherein the determining weights for each of the plurality of pixels comprises:

calculating a Laplace matrix corresponding to the pixel array; and

and distributing the weights of the pixels according to the Laplace values of the pixels in the Laplace matrix, wherein the weights of the pixels are positively correlated with the Laplace values of the pixels.

5. The method of any of claims 1-4, wherein the transmission performance is determined based on a transmission spectrum of forward incidence of the superstructural unit, which represents incidence of the superstructural unit from a side of the superstructural unit remote from the substrate, and a transmission spectrum of reverse incidence, which represents incidence of the substrate from a side of the substrate remote from the superstructural unit.

6. The method of claim 5, wherein the preset condition includes the transmittance of the forward incidence being greater than a first threshold and the transmittance of the reverse incidence being less than a second threshold, the first threshold being greater than the second threshold.

7. The method of any of claims 1-4, wherein the plurality of super-structure units are arranged in a symmetric expansion on the substrate.

8. The method of any of claims 1-4, wherein the refractive index of the metamaterial is greater than the refractive index of the substrate.

9. A method of fabricating an optical super-structured surface device, comprising: forming the plurality of super-structure units on the substrate using the description information generated in the method as claimed in any one of claims 1 to 8.

10. An optical super-structured surface device manufactured using the method of claim 9.

11. The device of claim 10, wherein each of the plurality of superstructural units has a size ranging from 700nm x 700nm to 2000nm x 2000nm.

12. The device of claim 10, wherein the cell pattern of a respective super-structure cell of the plurality of super-structure cells comprises 10 x 10 to 40 x 40 pixels; and wherein the size of each pixel ranges from 20nm by 20nm to 60nm by 60nm.

13. The device of claim 10, wherein the thickness of the metamaterial ranges from 100nm to 500nm.

14. The device of any of claims 10-13, wherein the material of the substrate is glass and the material of the metamaterial is silicon nitride.