Metalens
By designing the super-atom cross-arrangement and not completely identical pitch focal length of the super-lens, the problems of thickness and light field interference of traditional lenses are solved, and higher modulation transfer function values and better imaging quality are achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-17
- Publication Date
- 2026-03-20
AI Technical Summary
Traditional lenses have limitations in thickness and shape during the imaging process, and the refraction and scattering of light fields cause poor image quality, especially the generation of ghosting.
Design a meta-lens with meta atoms arranged in a cross pattern on a substrate, having not identical pitches and focal lengths. Employ a rectangular columnar phase retardation structure and a filler structure. The material is titanium dioxide, and the substrate is gallium nitride. The meta-atom array is distributed on the substrate, conforming to the Babiné principle.
The modulation transfer function value was improved, resulting in better image quality, reduced stray light and ghosting, and a thinner profile, thus reducing the impact of light field interference.
Smart Images
Figure CN224020010U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to an optical element, and more particularly to a metalen. Background Technology
[0002] For decades, optical lenses have been indispensable components in optical systems, used for applications such as imaging, focusing, and telescoping. However, traditional lenses have limitations, such as the impact of thickness and shape on image quality, and interference from refraction and scattering of the light field, which can produce stray light or ghosting in the image. These limitations lead to constraints in some applications.
[0003] Subsequently, meta-lenses were developed. However, there is still room for improvement in the modulation transfer function (MTF) of images produced by meta-lenses that generally use circular meta-atoms. Utility Model Content
[0004] This invention relates to a super-advanced lens that can effectively improve the modulation transfer function value and imaging quality.
[0005] One embodiment of this invention provides a meta-lens, comprising a substrate and a plurality of meta atoms. These meta atoms are distributed on the substrate, and each meta atom includes two phase retardation structures intersecting in a direction parallel to the substrate, wherein these meta atoms have not exactly the same pitch and not exactly the same focal length.
[0006] In the meta-lens of this embodiment, each metaatom includes two intersecting phase retardation structures in a direction parallel to the substrate, and these metaatoms have not exactly the same pitch and not exactly the same focal length. Therefore, the meta-lens of this embodiment can achieve a higher modulation transfer function value compared to a meta-lens using circular metaatoms, thereby effectively improving the imaging quality of the meta-lens.
[0007] To make the above-mentioned features and advantages of this utility model more apparent and understandable, specific embodiments are described below, and detailed descriptions are provided in conjunction with the accompanying drawings. Attached Figure Description
[0008] Figure 1A This is a front view schematic diagram of a super-lens according to an embodiment of the present invention.
[0009] Figure 1B for Figure 1A A magnified view of a portion of region M1.
[0010] Figure 2Afor Figure 1A A front view of a superatom in the diagram.
[0011] Figure 2B for Figure 1A A three-dimensional schematic diagram of a superatom in the image.
[0012] Figure 3 for Figure 1A A cross-sectional schematic diagram of the optical system of the super-lens.
[0013] Figure 4A for Figure 1A The super-lens converges perpendicularly incident parallel light onto the imaging plane. The light energy distribution curve along the line Y=0 is shown.
[0014] Figure 4B for Figure 1A The super-lens converges perpendicularly incident parallel light onto the imaging plane. The light energy distribution curve is shown on the straight line X=0.
[0015] Figure 5A for Figure 1A Another embodiment of the superlens focuses perpendicularly incident parallel light onto the imaging plane, showing the light energy distribution curve along the line Y=0.
[0016] Figure 5B for Figure 1A Another embodiment of the superlens focuses perpendicularly incident parallel light onto the imaging plane, showing the light energy distribution curve along a straight line of X=10 micrometers.
[0017] Figure 6 for Figure 4A and Figure 4B The modulation transfer function curves of the image formed by the light energy on the imaging surface on the line X=0 and the line Y=0.
[0018] Figure 7 for Figure 5A and Figure 5B The image formed by the light energy on the imaging surface is plotted as a curve of the modulation transfer function on the line X=10 micrometers and the line Y=0.
[0019] Figure 8 for Figure 4A and Figure 4B The modulation transfer function of the image formed by light energy on the imaging surface is compared with the modulation transfer function of a conventional metalens using circular metaatoms at a viewing angle of 0 degrees.
[0020] Figure 9 for Figure 5A and Figure 5BThe modulation transfer function of the image formed by light energy on the imaging surface is compared with the modulation transfer function of a conventional metalens using circular metaatoms at a viewing angle of 20 degrees.
[0021] Figure 10A for Figure 1A The distribution of the transverse index of a single metaatom in the Y direction in a metalens.
[0022] Figure 10B for Figure 1A The distribution of the transverse index of a single metaatom in the X direction in a metalens.
[0023] Figure 11 for Figure 1A The distribution of total transmittance and total reflectance of a single metaatom in the visible light band at different light exit angles. Detailed Implementation
[0024] Reference will now be made in detail to exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same element symbols are used in the drawings and description to denote the same or similar parts.
[0025] Figure 1A This is a front view schematic diagram of a super-lens according to an embodiment of the present invention. Figure 1B for Figure 1A A magnified view of a portion of region M1. Figure 2A for Figure 1A A front view of a superatom in the diagram. Figure 2B for Figure 1A A three-dimensional schematic diagram of a superatom in the image, and Figure 3 for Figure 1A A cross-sectional schematic diagram of the optical system of the superconducting lens. Please refer to... Figure 1A , Figure 1B , Figure 2A , Figure 2B and Figure 3 The meta-lens 100 of this embodiment includes a substrate 110 and a plurality of meta atoms 200. These meta atoms 200 are distributed on the substrate 110, and each meta atom 200 includes two intersecting phase retardation structures 210 and 220 in a direction parallel to the substrate 110. These meta atoms 200 have not identical pitches P and not identical focal lengths. In this embodiment, the design of these meta atoms 200 conforms to Babinet's principle.
[0026] In this embodiment, the two phase delay structures 210 and 220 intersect at a 90-degree angle. Each of the two phase delay structures 210 and 220 is rectangular in shape. That is, in this embodiment, the two intersecting phase delay structures 210 and 220 form a cross-shaped column, with a cross-shaped cross section parallel to the substrate 110.
[0027] Furthermore, in this embodiment, each metaatom 200 also includes a plurality of fillet structures 230 located beside the intersection of the two phase retardation structures 210 and 220. Figure 2A (Taking four filler structures 230 as an example). In this embodiment, the angles θ1 and θ2 between the side surface 232 of these filler structures 230 and the adjacent side surfaces 212 and 222 of the two phase delay structures 210 and 220 are, for example, 135 degrees.
[0028] In this embodiment, these metaatoms 200 are distributed on opposite surfaces 112 and 114 of the substrate 110 (e.g., Figure 3 (As shown). Furthermore, in this embodiment, the metaatoms 200 located on surface 112 and the metaatoms 200 located on surface 114 are mirror-symmetrical with respect to the substrate 110. In this embodiment, the material of these metaatoms 200 is, for example, titanium dioxide, and the material of the substrate 110 is, for example, gallium nitride, but this invention is not limited thereto. In this embodiment, Figure 3 To the left of surface 114 and its superatoms 200 is, for example, air, and Figure 3 The surface 112 and the superatoms 200 thereon are, for example, surrounded by air, with a refractive index of, for example, 1. The "phase retardation" of the phase retardation structures 210 and 220 refers to the fact that their materials have a large phase retardation effect relative to air. The material of the filler structure 230 can be the same as that of the phase retardation structures 210 and 220, and the filler structure 230 and the phase retardation structures 210 and 220 are, for example, integrally formed. In addition, in this embodiment, the substrate 110 is, for example, a circular substrate, and these superatoms 200 are arranged in an array on the substrate 110.
[0029] In the metasurface lens 100 of the present embodiment, each meta-atom 200 includes two phase delay structures 210 and 220 that intersect in a direction parallel to the substrate 110, and these meta-atoms 200 have pitch P and focal length that are not exactly the same. Therefore, the metasurface lens 100 of the present embodiment can achieve a higher modulation transfer function value compared to a metasurface lens using circular meta-atoms, thereby effectively improving the imaging quality of the metasurface lens 100. For example, for incident light with a wavelength of 520 nanometers, under the same effective focal length and within the range of a field of view angle of 0 to 20 degrees, the metasurface lens 100 of the present embodiment can achieve a higher modulation transfer function value compared to a general metasurface lens using circular meta-atoms. In addition, compared to a general traditional refractive lens, the thickness of the metasurface lens 100 of the present embodiment can be thinner and is less affected by interference such as refraction and scattering of the light field, so it is less likely to generate stray light or ghost images in imaging.
[0030] In the present embodiment, these metasurface lenses 100 satisfy:
[0031] 0.25 μm < P < 0.5 μm,
[0032] where P is the pitch of these meta-atoms 200.
[0033] In the present embodiment, each meta-atom 200 of the metasurface lens 100 satisfies:
[0034] 0.25 μm < W < 0.5 μm; and
[0035] 0.25 μm < H < 0.5 μm,
[0036] where W is the length of one of the two phase delay structures 210 and 220 (such as the phase delay structure 210) in a direction parallel to the substrate 110, and H is the length of the other of the two phase delay structures 210 and 220 (such as the phase delay structure 220) in a direction parallel to the substrate 110.
[0037] In the present embodiment, each meta-atom 200 of the metasurface lens 100 satisfies:
[0038] 0.5 μm < L < 1 μm,
[0039] where L is the height of the meta-atom 200 in a direction perpendicular to the substrate 110.
[0040] Figure 4A is Figure 1A The light energy distribution curve of the light energy converged by the metasurface lens of on the straight line of Y = 0 on the imaging surface, and Figure 4B is [[ID=The image shows the light energy distribution curve along the line X=0, where a superlens converges perpendicularly incident parallel light onto the imaging plane. Figure 1A The X and Y directions are parallel to the substrate 110, and the Z direction is perpendicular to the substrate 110. Furthermore, the X, Y, and Z directions are perpendicular to each other. Figure 4A and Figure 4B It can be seen that the light energy distribution is concentrated, and the super-lens 100 has good imaging quality.
[0041] Figure 5A for Figure 1A Another embodiment of the superlens converges perpendicularly incident parallel light onto the imaging plane, showing the light energy distribution curve along the line Y=0. Figure 5B for Figure 1A Another embodiment of the superlens focuses perpendicularly incident parallel light onto the imaging plane, showing the light energy distribution curve along a line of X = 10 micrometers. Please refer to... Figure 5A and Figure 5B In this embodiment, the metalens 100, through a design that appropriately distributes not entirely identical pitches P, causes the light emitted from the metalens 100 to be deflected by a 20-degree field of view in the X direction. For example... Figure 5A and Figure 5B As illustrated, even when the emitted light is deflected at a field of view of 20 degrees, the distribution of light energy remains concentrated, thus the superlens 100 still exhibits good imaging quality under these conditions.
[0042] Figure 6 for Figure 4A and Figure 4B The modulation transfer function curves of the image formed by the light energy on the imaging plane on the line X=0 and the line Y=0, and Figure 7 for Figure 5A and Figure 5B The image formed by the light energy on the imaging surface is plotted as a curve of the modulation transfer function on the line X=10 micrometers and the line Y=0. Figure 8 for Figure 4A and Figure 4B The modulation transfer function of the image formed by light energy on the imaging surface is compared with the modulation transfer function of a conventional superlens using circular superatoms at a viewing angle of 0 degrees. Furthermore, the two modulation transfer functions are... Figure 8 The terms "this embodiment" and "conventional super lens" are used to indicate this respectively. Figure 9 for Figure 5A and Figure 5B The graph shows the modulation transfer function of the image formed by light energy on the imaging surface and the modulation transfer function of a conventional superlens using circular superatoms at a viewing angle of 20 degrees. The graph also shows the modulation transfer functions of these two modulation transfer functions at... Figure 9The terms "this embodiment" and "conventional super-lens" are used respectively. Figures 6 to 9 It is known that, under the same effective focal length and within a field of view of 0 to 20 degrees, the superlens 100 of this embodiment can achieve a higher modulation transfer function value compared to a general superlens using circular super-atoms.
[0043] Figure 10A for Figure 1A A diagram showing the refractive index distribution of a single metaatom in the Y direction within a metalens. Figure 10B for Figure 1A The refractive index distribution of a single metaatom in a metalens in the X direction, and Figure 11 for Figure 1A The distribution of total transmittance and total reflectance of a single metaatom in the visible light band at different exit angles. Please refer to... Figure 10A , Figure 10B and Figure 11 , Figure 10A and Figure 10B The diagram illustrates the refractive index distribution of the superlens 100 at different positions in the X and Y directions, and is derived from... Figure 11 It can be seen that the super-atom 200 in this embodiment has good penetration, where high diffraction efficiency indicates high penetration.
[0044] In summary, in the meta-lens of the embodiments of this utility model, each meta-atom includes two phase retardation structures intersecting in a direction parallel to the substrate, and these meta-atoms have not exactly the same pitch and not exactly the same focal length. Therefore, the meta-lens of the embodiments of this utility model can achieve a higher modulation transfer function value compared with a meta-lens using circular meta-atoms, thereby effectively improving the imaging quality of the meta-lens.
[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.
Claims
1. A super-sensitive lens, characterized in that, Comprising: A substrate; And A plurality of metaatoms, distributed on the substrate, each metaatom including two phase delay structures intersecting in a direction parallel to the substrate, wherein the plurality of metaatoms have pitches that are not exactly the same and focal lengths that are not exactly the same.
2. The super-lens according to claim 1, characterized in that, Each metaatom further includes a plurality of corner filling structures located beside the intersection of the two phase delay structures.
3. The super-lens according to claim 2, characterized in that, The side surfaces of the plurality of corner filling structures form a 135-degree angle with the side surfaces adjacent to the two phase delay structures.
4. The super-lens according to claim 3, characterized in that, The two phase delay structures intersect at 90 degrees.
5. The super-lens according to claim 4, characterized in that, Each of the two phase delay structures is in the shape of a rectangular column.
6. The super-lens according to claim 1, characterized in that, The plurality of metasurface lenses satisfy: 0.25 μm < P < 0.5 μm, where P is the pitch of the plurality of metaatoms.
7. The super-lens according to claim 1, characterized in that, Each metaatom of the metasurface lens satisfies: 0.25 μm < W < 0.5 μm; and 0.25 μm < H < 0.5 μm, where W is the length of one of the two phase delay structures in a direction parallel to the substrate, and H is the length of the other of the two phase delay structures in a direction parallel to the substrate.
8. The super-lens according to claim 1, characterized in that, Each metaatom of the metasurface lens satisfies: 0.5 μm < L < 1 μm, where L is the height of the metaatom in a direction perpendicular to the substrate.
9. The super-lens according to claim 1, characterized in that, The plurality of metaatoms are distributed on opposite surfaces of the substrate.