Metasurface device, superlens, and imaging apparatus

Abstract

The embodiment of the invention provides a metasurface device, a super lens and imaging equipment, and the metasurface device comprises a non-local metasurface layer, a phase metasurface layer and a substrate. The phase metasurface layer is arranged in the substrate; the size of the non-local metasurface layer is not smaller than that of the phase metasurface layer, and the non-local metasurface layer covers an area where the phase metasurface layer is located; wherein the non-local metasurface layer is used for high-Q resonance spectrum regulation and control, and the phase metasurface layer is used for optical wavefront shaping.

Description

Technical Field

[0001] The present application relates to the field of imaging technology, and more particularly, to a metasurface device, a metalens, and an imaging device. Background Art

[0002] A metasurface is an ultrathin planar digital optical device with artificial sub-wavelength structures that can effectively manipulate electromagnetic waves. Traditional metasurfaces are based on the individual responses of each meta-unit and perform optical wavefront shaping within a broadband wavelength range. Such metasurfaces are called local metasurfaces. Non-local metasurfaces are mainly dominated by non-local responses generated by many interactions on extended meta-units, namely high-Q resonance modes.

[0003] Due to the mutually contradictory dominant mechanisms of local and non-local responses, it is difficult for metasurfaces to achieve independent control of high-Q resonance responses while manipulating optical wavefronts. Summary of the Invention

[0004] An object of the present application is to provide a metasurface device, a metalens, and an imaging device that can achieve regulation of high-Q resonance modes and wavefront regulation.

[0005] In a first aspect, the present application provides a metasurface device, comprising: a non-local metasurface layer, a phase metasurface layer, and a substrate; the phase metasurface layer is disposed within the substrate; the size of the non-local metasurface layer is not less than the size of the phase metasurface layer, and the non-local metasurface layer covers the region where the phase metasurface layer is located; wherein, the non-local metasurface layer is used for high-Q resonance spectrum regulation, and the phase metasurface layer is used for optical wavefront shaping.

[0006] In the above implementation, a non-local metasurface layer and a phase metasurface layer are provided. Since the non-local metasurface layer covers the region where the phase metasurface layer is located, it is possible to achieve the matching of the non-local metasurface layer with high-Q modes and the phase metasurface layer for wavefront regulation inside the substrate. Moreover, the non-local metasurface layer above the substrate covers the phase metasurface layer inside the substrate, so that the non-local metasurface layer is not less than the phase metasurface layer, thereby enabling spatial decoupling of the non-local metasurface and achieving independent control of regulating high-Q resonance modes and wavefront regulation.

[0007] In an alternative embodiment, the non-local metasurface layer includes a plurality of metasurface unit structures, and the plurality of metasurface unit structures form a matrix array.

[0008] In an alternative embodiment, the metasurface unit structure is a rectangular column structure, and the cross-section of the rectangular column structure is a square.

[0009] In an alternative embodiment, the height of the rectangular column structure ranges from 490 nm to 510 nm, and the side length of the cross-section of the rectangular column structure ranges from 570 nm to 590 nm.

[0010] In an alternative embodiment, the material of the metasurface unit structure is amorphous silicon.

[0011] In an alternative embodiment, the arrangement period of the metasurface unit structure ranges from 600 nm to 800 nm.

[0012] In an alternative embodiment, the surface of the non-local metasurface layer is square, and the side length of the square is not less than any side length of the phase metasurface layer. The side length of the square presented by the surface of the non-local metasurface layer ranges from 0.95 mm to 1.1 mm.

[0013] In an alternative embodiment, the wavefront modulation surface of the phase metasurface layer is square, and the side length of the wavefront modulation surface ranges from 700 μm to 900 μm.

[0014] In a second aspect, the present application provides a superlens, including the metasurface device according to any one of the foregoing embodiments, and the pixel points of the phase metasurface layer are of a preset size.

[0015] In a third aspect, the present application provides an imaging device, including the superlens according to the foregoing embodiment. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0017] Figure 1a Conceptual structural schematic diagram of the metasurface device provided by the embodiment of the present application;

[0018] Figure 1b Structural schematic diagram of the metasurface device provided by the embodiment of the present application;

[0019] Figures 2a to 2c Schematic diagram of the relative position relationship between the non-local metasurface layer and the phase metasurface layer of the metasurface device provided by the embodiment of the present application;

[0020] Figures 3a to 3c Some other schematic diagrams of the relative position relationship between the non-local metasurface layer and the phase metasurface layer of the metasurface device provided by the embodiment of the present application;

[0021] Figure 4 Flow chart of the design method of the metasurface device provided by the embodiment of the present application;

[0022] Figure 5a Schematic diagram of an example of the metasurface unit structure of the metasurface device provided by the embodiment of the present application;

[0023] Figure 5b Simulated transmission spectrum diagram of the metasurface device of an example provided by the embodiment of the present application;

[0024] Figure 6 Schematic diagram of the phase metasurface layer with focusing function shown in an example provided by the embodiment of the present application.

[0025] Icon: 10 - metasurface device; 110 - nonlocal metasurface layer; 120 - phase metasurface layer; P1 - center of the nonlocal metasurface layer; P2 - center of the phase metasurface layer. Detailed implementation manners

[0026] Next, the technical solutions in the embodiments of the present application will be described in conjunction with the accompanying drawings in the embodiments of the present application.

[0027] It should be noted that: Similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. At the same time, in the description of the present application, the terms "first", "second", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0028] In the description of the present application, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the inventive product is usually placed during use. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation of the present application.

[0029] In the description of the present application, it should also be noted that unless otherwise clearly defined and limited, the terms "set", "installed", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.

[0030] With the rapid development of photonics and nanotechnology, metasurfaces have become one of the main key devices for realizing planar optics. A metasurface is a thin planar digital optical device with artificial sub-wavelength structures that can effectively manipulate electromagnetic waves. Traditional metasurfaces are based on the individual responses of each meta-unit and perform optical wavefront shaping in a broadband wavelength range. Such metasurfaces are called local metasurfaces. Non-local metasurfaces are mainly dominated by non-local responses generated by interactions on extended meta-units. Non-local metasurfaces can support sharp spectral features, namely high-Q resonance modes. Due to the conflicting dominant mechanisms of the local response formed by local metasurfaces and the non-local response formed by non-local metasurfaces, it is difficult for metasurfaces to achieve independent control of high-Q resonance responses while realizing optical wavefront manipulation. That is, achieving independent control of optical wavefront manipulation while realizing high-Q resonance responses has become a current research difficulty.

[0031] Currently, the fusion strategies for the local response of local metasurfaces and the non-local response of non-local metasurfaces are all about finding a suitable balance point between the local phase control caused by the local response and the non-local resonance excitation dominated by the non-local response. Inevitably, this design method of finding the balance point needs to sacrifice some parameters, such as efficiency limitations, sacrifice of Q values, and increased difficulty in device fabrication. The inventors of this application have studied and learned that it is very difficult to completely decouple the phase control of the local response and the high-Q resonance response of the non-local response. However, if decoupling can be achieved, it can effectively solve the problems faced in achieving independent control of optical wavefront manipulation while realizing high-Q resonance responses. For example, the directions that can be solved include Q factor, mode, efficiency, device size, design flexibility, versatility, etc. Based on this, the inventors of this application have conducted research from the space decoupling method and proposed a metasurface that can achieve space decoupling.

[0032] Based on the above research, the inventors of this application provide a space-decoupled non-local metasurface and give a design method. The embodiments of this application provide a metasurface device, which includes a non-local metasurface layer for regulating high-Q resonance modes and a metasurface layer for realizing optical wavefront manipulation. Compared with traditional double-layer metasurfaces, this method does not increase the number of structural layers, has lower alignment requirements, and relatively less processing difficulty, providing for the realization of simultaneous and independent spectral and wavefront regulation. The following describes the metasurface device based on the above invention logic in combination with some embodiments.

[0033] Figure 1a and Figure 1b is a schematic structural diagram of the metasurface device 10 provided by the embodiment of this application. As Figure 1a and Figure 1b shown, the metasurface device 10 may include: a non-local metasurface layer 110, a phase metasurface layer 120, and a substrate.

[0034] In this embodiment, the phase metasurface layer 120 is disposed within the substrate.

[0035] Optionally, the phase metasurface layer 120 may include nanostructure units. The nanostructure units may have birefringence. The phase metasurface layer 120 may be an internal birefringent nanostructure unit formed by a laser processing method.

[0036] Optionally, the substrate may be a glass substrate. The phase metasurface layer 120 may be a phase metasurface layer 120 having birefringent nanostructure units obtained by processing the glass substrate.

[0037] The size of the nonlocal metasurface layer 110 is not less than the size of the phase metasurface layer 120, and the nonlocal metasurface layer 110 covers the region where the phase metasurface layer 120 is located.

[0038] Specifically, refer to Figure 1a As shown, the nonlocal metasurface layer 110 covering the phase metasurface layer 120 may mean that the size of the nonlocal metasurface layer 110 in the XY direction is not less than the size of the phase metasurface layer 120 in the XY direction, and the region where the nonlocal metasurface layer 110 is located in the XY direction covers the region where the phase metasurface layer 120 is located in the XY direction. Since only the region where the nonlocal metasurface layer 110 is located in the XY direction needs to cover the region where the phase metasurface layer 120 is located in the XY direction, the requirements for the positions of the nonlocal metasurface layer and the phase metasurface layer 120 are relatively low, and the center P1 of the nonlocal metasurface layer and the center P2 of the phase metasurface layer do not need to be completely aligned in the z direction. It can be understood that Figure 1a The orientation shown is only schematic. Different arrangements of the nonlocal metasurface layer 110 covering the phase metasurface layer 120 may correspond to different directions presented by the covering region. For example, the metasurface device 10 is Figure 1a rotated counterclockwise by 90 degrees in the state shown, then the region where the nonlocal metasurface layer 110 is located in the XZ direction covers the region where the phase metasurface layer 120 is located in the XZ direction.

[0039] Among them, the nonlocal metasurface layer 110 is used for high-Q resonance spectrum regulation, and the phase metasurface layer 120 is used for optical wavefront shaping.

[0040] In this embodiment, the size of the nonlocal metasurface layer 110 may be equal to the size of the phase metasurface layer 120, or the size of the nonlocal metasurface layer 110 may be greater than the size of the phase metasurface layer 120.

[0041] The nonlocal metasurface layer 110 covering the region where the phase metasurface layer 120 is located can be understood as that any region on the surface of the phase metasurface layer 120 does not exceed the covering region of the surface of the nonlocal metasurface layer 110.

[0042] Exemplarily, when the non-local metasurface layer 110 has the same shape, for example, the surfaces of both the non-local metasurface layer 110 and the phase metasurface are rectangular, each side of the rectangle of the non-local metasurface layer 110 is not less than the corresponding side of the phase metasurface layer 120. Optionally, the center of the surface of the non-local metasurface layer 110 and the center of the phase metasurface may be aligned; the center of the surface of the non-local metasurface layer 110 and the center of the phase metasurface may not be aligned, as long as the edge of the phase metasurface does not exceed the surface coverage area of the non-local metasurface layer 110. Figures 2a to 2c Schematic diagram of the relative position relationship between the non-local metasurface layer 110 and the phase metasurface layer 120 provided in the embodiment of the present application. Figures 2a to 2c The example shown is a schematic diagram of the non-local metasurface layer 110 and the phase metasurface layer 120 in the XY direction. Figures 2a to 2c In the example shown, the surfaces of both the non-local metasurface layer 110 and the phase metasurface layer 120 are rectangular. Figure 2a It shows a schematic diagram in which the center P1 of the non-local metasurface layer and the center P2 of the phase metasurface layer are not aligned, but the non-local metasurface layer 110 completely covers the phase metasurface layer 120. Figure 2b It shows a schematic diagram in which the center P1 of the non-local metasurface layer and the center P2 of the phase metasurface layer are aligned. Since each side length of the rectangle presented by the surface of the non-local metasurface layer 110 is greater than each side length of the rectangle presented by the surface of the phase metasurface layer 120, the non-local metasurface layer 110 completely covers the phase metasurface layer 120. Figure 2c It shows a schematic diagram in which the center P1 of the non-local metasurface layer and the center P2 of the phase metasurface layer are aligned, and each side length of the rectangle presented by the surface of the non-local metasurface layer 110 is equal to the corresponding side length of the rectangle presented by the surface of the phase metasurface layer 120. Therefore, the non-local metasurface layer 110 completely covers the phase metasurface layer 120.

[0043] For another example, the surfaces of both the non-local metasurface layer 110 and the phase metasurface are circular, then the diameter of the circle presented by the surface of the non-local metasurface layer 110 is not less than the diameter of the circle presented by the surface of the phase metasurface layer 120. Figures 3a to 3c In the example shown, the surfaces of both the non-local metasurface layer 110 and the phase metasurface layer 120 are circular.

[0044] Figure 3a It shows a schematic diagram in which the center of the circle of the non-local metasurface layer 110 and the center of the circle of the phase metasurface layer 120 are not aligned, but the non-local metasurface layer 110 completely covers the phase metasurface layer 120.

[0045] Figure 3bIt is shown that the centers of the non-local metasurface layer 110 and the phase metasurface layer 120 are aligned. Since the diameter of the circle presented by the surface of the non-local metasurface layer 110 is larger than the diameter of the circle presented by the surface of the phase metasurface layer 120, the non-local metasurface layer 110 completely covers the phase metasurface layer 120. Figure 3c It is shown that the centers of the non-local metasurface layer 110 and the phase metasurface layer 120 are in an aligned state, and the side lengths of each side of the circle presented by the surface of the non-local metasurface layer 110 are equal to the corresponding side lengths of the circle presented by the surface of the phase metasurface layer 120. Therefore, the non-local metasurface layer 110 completely covers the phase metasurface layer 120.

[0046] Among them Figures 2a to 2c and Figures 3a to 3c It shows the non-local metasurface layer 110 and the phase metasurface layer 120 in several states. Based on different actual requirements, the non-local metasurface layer 110 and the phase metasurface layer 120 can also be other shaped metasurface layers. Due to the deviation of the real-time manufacturing process, there may also be some differences in the phase positions of the non-local metasurface layer 110 and the phase metasurface layer 120. It can be understood that as long as the non-local metasurface layer 110 can completely cover the phase metasurface layer 120.

[0047] In this embodiment, the non-local metasurface layer 110 and the phase metasurface layer 120 are provided. Since the non-local metasurface layer 110 covers the area where the phase metasurface layer 120 is located, the non-local metasurface layer 110 with a high-Q mode can be matched with the phase metasurface layer 120 for wavefront regulation inside the substrate, and the non-local metasurface layer 110 above the substrate covers the phase metasurface layer 120 inside the substrate, so that the non-local metasurface layer 110 is not smaller than the phase metasurface layer 120, thus enabling spatial decoupling of the non-local metasurface and realizing independent control of regulating the high-Q resonance mode and wavefront regulation. Further, in the above-mentioned non-local metasurface layer 110 and phase metasurface layer 120, they do not need to be completely aligned, and only the non-local metasurface layer 110 needs to cover the area where the phase metasurface layer 120 is located. In this way, from the perspective of processing and manufacturing, the implementation difficulty is relatively low and it does not affect the independent control of regulating the high-Q resonance mode and wavefront regulation.

[0048] In this embodiment, the non-local metasurface layer 110 includes a plurality of metasurface unit structures, and the plurality of metasurface unit structures form a matrix array.

[0049] The matrix array arranged by each metasurface unit structure can have the same number of rows and columns. Figure 1a and Figure 1bIn the illustrated example, the non-local metasurface layer 110 includes a metasurface unit structure of four rows and four columns. Of course, based on different target requirements for the high-Q resonance mode required by the actual non-local metasurface layer 110, the non-local metasurface layer 110 may also include a greater or smaller number of metasurface unit structures, Figure 1a and Figure 1b merely exemplary, the number of metasurface unit structures provided in the embodiments of the present application is not limited to Figure 1a and Figure 1b the example shown.

[0050] In the above implementation, by arranging the metasurface unit structures in a matrix array, it is possible to achieve maximized energy storage efficiency and a high-Q resonance response on the basis of minimizing energy loss.

[0051] Optionally, the metasurface unit structure is a rectangular column structure, and the cross-section of the rectangular column structure is a square.

[0052] In this embodiment, the height of the rectangular column structure may be greater than the side length of the cross-section of the rectangular column structure. The height of the rectangular column structure may also be smaller than the side length of the cross-section of the rectangular column structure. The height of the rectangular column structure may also be the same as the side length of the cross-section of the rectangular column structure. Specifically, it can be determined based on the actual requirements of the high-Q resonance mode. For example, it can be determined based on requirements such as the resonance band, quantity, Q value, etc. to determine the height and cross-sectional side length of the rectangular column structure.

[0053] In this embodiment, the value range of the height of the rectangular column structure includes 490 nm to 510 nm. Exemplarily, the value of the height of the rectangular column structure can be one of the values such as 490 nm, 495 nm, 500 nm, 505 nm, 510 nm, etc.

[0054] In this embodiment, the value range of the side length of the cross-section of the rectangular column structure includes 570 nm to 590 nm. Exemplarily, the value of the side length of the cross-section of the rectangular column structure can be one of the values such as 570 nm, 575 nm, 580 nm, 585 nm, 590 nm, etc.

[0055] In the above implementation, by setting the rectangular column structure to have a square cross-section and a height slightly smaller than the value of the side length of the cross-section of the rectangular column structure, a metasurface unit structure matrix array formed can better absorb the required wavelength and achieve a high-Q resonance response. Specifically, when the value of the height of the rectangular column structure is in the range of 490 nm to 510 nm and the side length of the cross-section of the rectangular column structure is in the range of 570 nm to 590 nm, the resonance wavelengths of the dual-band high-Q resonance mode achieved by the non-local metasurface layer 110 can be 1130.4 nm and 1276.6 nm respectively.

[0056] Optionally, the material of the metasurface unit structure can be amorphous silicon (α-Si).

[0057] Since the atoms of amorphous silicon are arranged in a random network, there are dangling bonds (unsaturated chemical bonds) and defect states, resulting in a large number of localized states in the bandgap. And it has a high light absorption coefficient, so that a high-Q resonance response can be better achieved.

[0058] In this embodiment, the value range of the arrangement period of the metasurface unit structure includes 600 nm to 800 nm. The value of the arrangement period of the metasurface unit structure can be one of values such as 600 nm, 630 nm, 650 nm, 680 nm, 700 nm, 730 nm, 750 nm, 780 nm, 800 nm, etc.

[0059] Among the values of the arrangement period of the metasurface unit structure mentioned above, it can achieve a better high-Q resonance at the required resonance wavelength.

[0060] The surface of the non-local metasurface layer 110 can be square, and the side length of the square is not less than any side length of the phase metasurface layer 120. The value range of the side length of the square formed by the surface of the non-local metasurface layer 110 includes 0.95 mm to 1.1 mm.

[0061] The value of the side length of the square formed by the surface of the non-local metasurface layer 110 can be one of values such as 0.95 mm, 0.98 mm, 1 mm, 1.05 mm, 1.1 mm, etc.

[0062] The wavefront modulation surface of the phase metasurface layer 120 can be square, and the value range of the side length of the wavefront modulation surface includes 700 μm to 900 μm.

[0063] The value range of the side length of the wavefront modulation surface can be one of values such as 700 μm, 730 μm, 750 μm, 800 μm, 750 μm, 900 μm, etc.

[0064] Next, the formation of the spatially decoupled non-local metasurface will be described in combination with the design logic of the non-local metasurface, as Figure 4 shown, the design method of the non-local metasurface can include the following steps.

[0065] Step 210, determine the target requirements of the high-Q resonance mode, and perform parameter scanning to design the non-local metasurface structure to obtain the initial high-Q resonance mode.

[0066] Exemplarily, the target requirements of the high-Q resonance mode can include the resonance band, quantity, Q value, etc.

[0067] Exemplarily, the target requirements for the high-Q resonance mode may include obtaining a dual-band high-Q resonance mode in the near-infrared band.

[0068] Exemplarily, to obtain dual-band high-Q resonance in the near-infrared band, a rectangular column structure can be selected as the metasurface unit structure to better absorb the near-infrared band.

[0069] Exemplarily, based on the above target requirements, amorphous silicon can be selected as the material of the metasurface unit structure, which has a high light absorption coefficient to improve the dual-band high-Q resonance response.

[0070] Perform parameter scanning on the cross-sectional side length L, height H, and period P of the rectangular column structure of the metasurface unit structure to initially obtain a dual-band high-Q resonance mode that meets the target requirements.

[0071] Step 220: Perform mode analysis on the initial high-Q resonance mode and optimize the transmission spectrum of the initial high-Q resonance mode.

[0072] By optimizing the transmission spectrum, under the condition of circularly polarized light perpendicular incidence, the nonlocal metasurface layer 110 obtained can maintain high-Q high transmittance at the high-Q resonance mode while maintaining low transmittance at other nearby wavelengths.

[0073] In the above step 220, the content of optimizing the transmission spectrum may include optimizing the Q value, transmittance, filtering performance, etc. of the high-Q resonance mode.

[0074] Optionally, the means of optimizing the initially designed dual-band high-Q resonance mode may include: using means such as the mode field distribution and multipole decomposition at the resonance position to judge the generation mechanism of the resonance mode. Then, further optimize parameters such as the Q value and transmittance of the dual-band high-Q resonance mode.

[0075] Optionally, the process of optimizing the transmission spectrum of the initial high-Q resonance mode may include: parameter scanning, topology optimization, etc.

[0076] Through the optimization in the above step 220, a nonlocal metasurface layer 110 with filtering characteristics that meets the target requirements of the high-Q resonance mode can be obtained.

[0077] In one example, the period of the metasurface of the nonlocal metasurface layer 110 is 700 nm, the height H of the rectangular column structure of the metasurface unit structure is 500 nm, and the cross-sectional side length L of the metasurface unit structure is 580 nm. In the above example, the resonance wavelengths of the simulated dual-band high-Q resonance mode are 1130.4 nm and 1276.6 nm respectively. Specifically, it can be as Figure 5a and Figure 5b shown, Figure 5a which is a schematic diagram of an example of the metasurface unit structure of the metasurface device in one example.Figure 5b The simulated transmission spectrum of a metasurface device for an example. In Figure 5a In the example shown, the material of the metasurface unit structure is amorphous silicon (α-Si). The cross-sectional side length L and period P of the metasurface unit structure. In Figure 5b In the example shown, it can be obtained from the simulated transmission spectrum that the transmittance is high at the positions where the resonance wavelengths are 1130.4 nm and 1276.6 nm respectively, and the value is close to 1; while the transmittance is low at other wavelengths, and the value is close to 0.

[0078] Step 230, based on the requirements of optical wavefront modulation, determine the phase arrangement of the phase metasurface layer 120 in the glass substrate.

[0079] Exemplarily, the requirements of optical wavefront modulation may include requirements such as lens phase, orbital angular momentum (OAM) mode modulation, etc.

[0080] Pixel points can be divided in the glass substrate to determine the phase arrangement of the phase metasurface in the glass substrate.

[0081] In one example, the designed metasurface device 10 can be used in a metalens, that is, the phase metasurface layer 120 in the glass substrate needs to have a focusing function. The pixel points designed here are 1 μm × 1 μm, and the designed phase metasurface layer 120 can be used as a focusing phase surface, and the size of the wavefront modulation surface of the phase metasurface layer 120 is 800 μm × 800 μm. Of course, based on different actual required resolutions, the size of the pixel points is different. For example, in the case of higher required resolution, the pixel points can be designed to be smaller, and in the case of relatively lower required resolution, the size of the pixel points can be designed to be larger.

[0082] In this embodiment, after the phase metasurface layer 120 is designed, the phase of the phase metasurface layer 120 can be processed in the glass substrate by using femtosecond laser processing.

[0083] In one example, the phase metasurface layer 120 can be Figure 6 A focusing phase surface with a focusing function as shown. Among them, based on different requirements of optical wavefront modulation, the form presented by the phase metasurface layer 120 can be different.

[0084] Step 240, cover the phase metasurface inside the glass substrate with the non-local metasurface layer 110 of the high-Q resonance mode.

[0085] In this embodiment, the area size of the surface of the non-local metasurface layer 110 above the glass substrate is greater than or equal to the area size of the phase metasurface layer 120 inside the glass substrate. Exemplarily, the shape of the surface of the non-local metasurface layer 110 can be a shape that is an equi-scaled enlargement of the surface of the phase metasurface layer 120.

[0086] Based on the above steps 210 to 240, a design of a spatially decoupled non-local metasurface is formed.

[0087] Optionally, the high-Q resonance mode can be a Fano resonance, a Lorentzian line shape, etc. In this embodiment, the high-Q resonance mode must maintain good filtering characteristics.

[0088] In a practical optional design, the final designed size of the non-local metasurface layer 110 can be 1.05 mm × 1.05 mm. If the phase metasurface layer 120 inside the glass substrate can be covered by the non-local metasurface layer 110, the design of the dual-wavelength selective high-Q superlens is completed.

[0089] In the above design logic, the center P1 of the non-local metasurface layer and the center P2 of the phase metasurface layer inside the substrate do not need to be completely aligned. As long as the size of the non-local metasurface layer 110 in the horizontal direction region covers the size of the phase metasurface layer 120 inside the glass substrate, it is sufficient.

[0090] Optionally, for different usage requirements, the target requirement of the high-Q resonance mode can be to achieve a dual-wavelength selective high-Q superlens, or it can also be designed by using the metasurface design method of the above steps 210 to 240, and a high-Q dual-wavelength focusing function can be achieved.

[0091] The above design logic provided by the embodiments of the present application can achieve the decoupling of the high-Q oscillation dominated by non-local response and the spatial wavefront dominated by local response, and solves the problem that it is difficult for a metasurface to independently control a high-Q resonance response while manipulating the optical wavefront. Compared with the prior art, the above design logic is simple, the manufacturing implementation of the metasurface device 10 is also relatively simple, and the number of structural layers is not increased. The alignment requirement between the non-local metasurface layer 110 and the phase metasurface layer 120 is low, and the processing difficulty is small.

[0092] The embodiments of the present application provide a superlens, which includes a metasurface device 10, and the pixel points of the phase metasurface layer 120 of the metasurface device 10 are of a preset size.

[0093] Optionally, the pixel points of the phase metasurface layer 120 of the metasurface device 10 can be 1 μm × 1 μm. Of course, based on different actual requirements, the pixel points can also be larger or smaller pixels.

[0094] The metasurface device 10 provided in this embodiment may be similar to the metasurface device 10 provided in the foregoing embodiment. For other details of the metasurface device 10, reference may be made to the description in the foregoing embodiment, which will not be elaborated herein.

[0095] An embodiment of the present application provides an imaging device including a metalens.

[0096] The metalens provided in this embodiment may be similar to the metalens provided in the foregoing embodiment. For other details of the metalens, reference may be made to the description in the foregoing embodiment, which will not be elaborated herein.

[0097] Optionally, the imaging device may be an Augmented Reality (AR) imaging device, a Virtual Reality (VR) device, or a biological imaging device. Depending on the requirements of the actual imaging device, the imaging device may further include other components. For example, the imaging device may further include components such as a processor and a memory.

[0098] The above are only optional embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and modifications. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application. It should be noted that similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0099] As described above, the above is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed by the present application, and all should be covered by the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A metasurface device, characterized in that, Comprising: A non-local metasurface layer, a phase metasurface layer, and a substrate; The phase metasurface layer is disposed within the substrate; The size of the non-local metasurface layer is not less than the size of the phase metasurface layer, and the non-local metasurface layer covers the area where the phase metasurface layer is located; wherein, the non-local metasurface layer is used for high-Q resonance spectrum regulation, and the phase metasurface layer is used for optical wavefront shaping.

2. The metasurface device according to claim 1, wherein The non-local metasurface layer includes a plurality of metasurface unit structures, and the plurality of metasurface unit structures form a matrix array.

3. The metasurface device according to claim 2, wherein The metasurface unit structure is a rectangular column structure, and the cross-section of the rectangular column structure is a square.

4. The metasurface device according to claim 3, wherein The value range of the height of the rectangular column structure includes 490 nm to 510 nm, and the value range of the side length of the cross-section of the rectangular column structure includes 570 nm to 590 nm.

5. The metasurface device according to claim 2, wherein The material of the metasurface unit structure is amorphous silicon.

6. The metasurface device according to claim 2, wherein The value range of the arrangement period of the metasurface unit structure includes 600 nm to 800 nm.

7. The metasurface device according to any one of claims 1-6, characterized in that The surface of the non-local metasurface layer is square, and the side length of the square is not less than any side length of the phase metasurface layer. The value range of the side length of the square presented by the surface of the non-local metasurface layer includes 0.95 mm to 1.1 mm.

8. The metasurface device according to any one of claims 1-6, characterized in that, The wavefront regulation surface of the phase metasurface layer is square, and the value range of the side length of the wavefront regulation surface includes 700 μm to 900 μm.

9. A metalens, characterized in that, Including the metasurface device according to any one of claims 1-8, wherein the pixel points of the phase metasurface layer are of a preset size.

10. An imaging device, characterized in that, Including the superlens according to claim 9.

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