Metasurface optical device, optical system, method for correcting aberrations

Abstract

Some embodiments of the present disclosure provide a metasurface device. The metasurface device includes an array of a plurality of metasurfaces, wherein each of the metasurfaces includes a multilayer stack of layers, the stack of layers including at least a first layer having a first refractive index and a second layer having a second refractive index, and the first refractive index is different from the second refractive index. The present disclosure also relates to an optical system including the metasurface device and a method for correcting aberrations.

Description

Technical Field

[0001] This disclosure relates to an optical device, and more particularly to an optical device comprising metasurfaces. Background Technology

[0002] In recent years, metasurfaces have attracted considerable attention in the field of optics. For example, metasurfaces can be used with image sensors (e.g., complementary metal-oxide-semiconductor (CMOS)) and image sensors (CMOS image sensors, CIS). CMOS image sensor products are used in digital cameras, camera phones, webcams, laptop security devices, automobiles, medical devices, and more. Metasurfaces can modulate the properties of electromagnetic waves (e.g., incident waves). For example, metasurfaces can be used as lenses, polarizers, beam-shaping devices, tunable phase modulators, etc. Furthermore, metasurfaces can be designed to correct aberrations, including spherical aberration and chromatic aberration, thus improving image quality. Summary of the Invention

[0003] Some embodiments of this disclosure provide a meta-optical device. The meta-optical device includes an array of a plurality of meta-structures, wherein each meta-structure includes multiple stacked layers, the stacked layers including at least a first layer having a first refractive index and a second layer having a second refractive index, and the first refractive index and the second refractive index are different.

[0004] In some embodiments, the difference between the first refractive index and the second refractive index is between 0.1 and 2.5. In some embodiments, the difference between the first refractive index and the second refractive index is between 0.3 and 2.0. In some embodiments, the difference between the first refractive index and the second refractive index is between 0.5 and 1.8. In some embodiments, the metastructure includes a dielectric material.

[0005] In some embodiments, the stacked layers further include a third layer having a third refractive index, which is different from the second refractive index, and the second layer is located between the first layer and the third layer. In some embodiments, the second refractive index is greater than both the first and third refractive indices, and the first and third refractive indices are the same. In some embodiments, a first thickness of the first layer is different from a second thickness of the second layer. In some embodiments, the first thickness and a third thickness of the third layer are greater than the second thickness, and the first and third thicknesses are the same.

[0006] In some embodiments, each of the metastructures has an aspect ratio of less than 10. In some embodiments, each of the metastructures, when viewed from above, has a circular, elliptical, polygonal, or hollow polygonal shape. In some embodiments, the metastructures are arranged in an array of rectangles or hexagons. In some embodiments, the metastructures include different geometries, sizes, or orientations. In some embodiments, the stacked layers further include multiple odd-numbered layers having a first refractive index and multiple even-numbered layers having a second refractive index.

[0007] Some embodiments of this disclosure provide an optical system. The optical system includes an image sensor and a meta-optical device. The image sensor includes a plurality of microlenses and a plurality of color filters. The color filters are disposed below the microlenses. The meta-optical device is disposed above the color filters. The meta-optical device includes an array of a plurality of meta-structures, each meta-structure including multiple stacked layers, the stacked layers including a first layer having a first refractive index and a second layer having a second refractive index, wherein the first refractive index and the second refractive index are different.

[0008] In some embodiments, the super-optical device is disposed above the microlens and the color filter, or between the microlens and the color filter. In some embodiments, the distance between a bottom surface of the super-optical device and a top surface of the image sensor is less than 10 micrometers. In some embodiments, the distance between a bottom surface of the super-optical device and a top surface of the image sensor is between 10 micrometers and 1 millimeter. In some embodiments, the distance between a bottom surface of the super-optical device and a top surface of the image sensor is between 1 millimeter and 3 millimeters.

[0009] Some embodiments of this disclosure provide a method for correcting aberrations. The method includes calculating a desired amount for aberration correction. The method also includes determining a desired location for a meta-optical device, wherein the meta-optical device is disposed adjacent to an image sensor, and a distance between the meta-optical device and the image sensor is between 10 micrometers and 3 millimeters. The meta-optical device includes an array of multiple meta-structures, each meta-structure including multiple stacked layers, the stacked layers including a first layer having a first refractive index and a second layer having a second refractive index, wherein the first refractive index and the second refractive index are different. The method further includes adjusting the geometry, size, or alignment of the meta-structures and positioning the meta-optical device according to the desired amount and desired location. Attached Figure Description

[0010] To make the features or advantages of this disclosure more apparent and understandable, some embodiments are provided and described in detail below with reference to the accompanying drawings.

[0011] Figures 1A to 1CThe positional relationship between the super-optical device and the image sensor is schematically shown.

[0012] Figures 2A to 2L Different super-optical devices are schematically shown.

[0013] Figures 3A to 3E The diagram schematically illustrates the relationship between the efficiency of several different superjunctions and the wavelength of the incident wave.

[0014] Figure 4A The geometric changes of the superstructure are schematically shown.

[0015] Figure 4B The dimensional variations of the superstructure are schematically illustrated.

[0016] Figure 4C The diagram schematically illustrates the changes in the orientation of the superstructure.

[0017] Figure 4D The phase change of an incident wave with an incident angle of approximately 15 degrees is schematically shown.

[0018] Figures 5A to 5C The simulation process of aberration correction is illustrated schematically.

[0019] Figure 5D as well as Figure 5E The result of aberration correction for the incident wave is shown schematically.

[0020] Figure 6 This is a flowchart of a method for correcting aberrations.

[0021] The reference numerals in the attached figures are explained as follows:

[0022] 1: Optical System

[0023] 10: Camera

[0024] 20: Image Sensor

[0025] 21: Microlenses

[0026] 22: Color Filter

[0027] 23: Photosensitive layer

[0028] 24: Metallic opaque layer

[0029] 25: Silicon transistor

[0030] 50: Filler material

[0031] 100, 100A, 100B, 100C, 100D, 100E, 100F, 100G, 100H, 100I, 100J, 100K, 100L, 100X, 100Y, 100Z: Super-intelligent optical devices

[0032] 110, 110A, 110B, 110C, 110D, 110E, 110F, 110G, 110H, 110I, 110J, 110K, 110L, 110X, 110Y, 110Z: Superstructure

[0033] 111A: First Floor

[0034] 112A: Second Floor

[0035] 113A: Third Floor

[0036] 111I, 112I, 113I, 114I, 111J, 112J, 113J, 114J, 115J, 111K, 112K, 113K, 114K, 115K, 111L, 112L, 113L, 114L, 115L: Layers

[0037] 115X: Angle

[0038] 600: Method

[0039] 601, 602, 603, 604: Steps

[0040] D: Diameter

[0041] T1: First thickness

[0042] T2: Second thickness

[0043] T3: Third Thickness

[0044] W: Incident wave

[0045] θ1: Original angle of incidence

[0046] θ2: Corrected angle

[0047] θ in Angle of incidence

[0048] Δθ: Change in rotation angle Detailed Implementation

[0049] This specification provides numerous different embodiments or examples to implement various features of this disclosure. The specific examples of the various components and arrangements described below are for the purpose of simplifying this disclosure. These are, of course, merely examples and are not intended to be limiting. For example, if this specification describes a first feature formed "on" or "above" a second feature, it indicates that it may include embodiments where the first and second features are in direct contact, or embodiments where an additional feature is formed between the first and second features, so that the first and second features are not in direct contact. The ordinal numbers used in this specification, such as "first," "second," etc., do not have a sequential relationship and are only used to distinguish two different elements with the same name. Furthermore, repeated symbols or letters may be used in different examples of this disclosure.

[0050] Furthermore, spatial terms, such as "above," are used to facilitate the description of the relationship between elements or features in a diagram and other elements or features. In addition to the orientation shown in the diagram, these spatial terms are intended to encompass different orientations of the device in use or operation. If the device can be rotated to different orientations (rotated 90 degrees or other orientations), the spatial terms used here can be interpreted in the same way.

[0051] According to some embodiments, an optical system 1 is provided. The optical system 1 includes an image sensor 20 and an ultra-sensitive optical device 100. The image sensor 20 corresponds to a camera 10. Please refer to... Figures 1A to 1C . Figures 1A to 1C The positional relationship between the image sensor 20 and the super-optical device 100 is schematically shown. An incident wave W passing through the camera 10 can be converted into an image on the image sensor 20. In some embodiments, the image sensor 20 may be a complementary metal-oxide-semiconductor image sensor. The image sensor 20 may include one or more microlenses 21, one or more color filters 22, one or more optical sensor layers 23, one or more isolated metal layers 24, and one or more silicon transistors 25.

[0052] like Figure 1A As shown, the super-optical device 100 can be disposed inside the image sensor 20. More specifically, in Figure 1A In this configuration, the super-optical device 100 is disposed between the microlens 21 and the color filter 22. In other words, the super-optical device 100 is disposed below the microlens 21 and above the color filter 22, the photosensitive layer 23, the opaque metallic layer 24, and the silicon transistor 25.

[0053] like Figure 1B as well as Figure 1C As shown, the super-optical device 100 can be positioned above the image sensor 20. Specifically, in Figure 1B as well as Figure 1C In the middle, the super-intelligent optical device 100 is disposed above the microlens 21, the color filter 22, the photosensitive layer 23, the metal opaque layer 24, and the silicon transistor 25. Figure 1B and Figure 1C The difference lies in Figure 1C In the image sensor 20, the super-optical device 100 is relatively far from the image sensor 20. Furthermore, in... Figure 1B In this process, a filling material 50 may be disposed between the super-optical device 100 and the image sensor 20.

[0054] The super-optical device 100 provides two optical functions: phase correction and aberration correction. When the super-optical device 100 functions as a phase corrector, the phase of the incident wave W can be modulated. When the super-optical device 100 functions as an aberration corrector, it can improve the performance of the image sensor 20 and / or improve image quality. The function of the super-optical device 100 may depend on its position relative to the image sensor 20.

[0055] In some embodiments, when the super-optical device 100 is disposed inside the image sensor 20, or when the super-optical device 100 is disposed above the image sensor 20 and at a distance of less than 10 micrometers (μm) from the image sensor 20, the super-optical device 100 can be considered as a phase corrector. For example, such as Figure 1A as well as Figure 1B As shown, the dashed line represents the wavefront of the incident wave W. After the incident wave W passes through the super-optical device 100, the originally tilted wavefront can be changed to be horizontal and substantially parallel to the top surface of the color filter 22. That is, the phase of the incident wave W is modulated.

[0056] In some embodiments, when the superoptical device 100 is positioned above the image sensor 20 and the distance between the superoptical device 100 and the image sensor 20 is between 1 millimeter (mm) and 3 millimeters, the superoptical device 100 can be considered as an aberration corrector. For example... Figure 1C As shown, the imaging quality on the image sensor 20 can be improved by means of the super-optical device 100. As for those cases where the distance between the super-optical device 100 and the image sensor 20 is between 10 micrometers and 1 millimeter, the super-optical device 100 can be regarded as a combination of a phase corrector and an aberration corrector.

[0057] The positional relationship between the image sensor 20 and the super-optical device 100 can be adjusted according to actual needs. Figures 1A to 1C In this embodiment, the optical system 1 includes only one super-optical device 100. In some other embodiments, the optical system 1 may include multiple super-optical devices 100, some of which serve as phase correctors and others as aberration correctors.

[0058] In the following content, the same or similar symbols are used to refer to the same or similar elements. Please refer to [reference needed]. Figures 2A to 2L . Figures 2A to 2L The superstructure optical devices 100A to 100L are schematically shown. The superstructure optical devices 100A to 100L include an array of superstructures 110A to 110L. The superstructures 110A to 110L may include dielectric materials, metallic materials, etc. For example, the superstructures 110A to 110L may be made of carbon nanotubes (CNTs), two-dimensional transition metal dichalcogenides (2D TMDs), SiC, ZrO2, ZrO 2-x TiO x SiN x It is made of indium tin oxide (ITO), Si, a-Si, group III-V semiconductor compounds, or combinations thereof. The metastructures 110A to 110L can be arranged in an array of rectangles or hexagons. For ease of explanation, only the rectangular arrangement is shown.

[0059] In this disclosure, each of the metastructures 110A to 110L comprises a multilayer stack with different refractive indices. For example, each of the metastructures 110A to 110L may respectively comprise at least two layers having the highest refractive index and the second highest refractive index. Figures 2A to 2L In this diagram, different refractive indices are represented by different patterns. In some embodiments, the difference between the highest and second-highest refractive indices is between 0.1 and 2.5. In some embodiments, the difference between the highest and second-highest refractive indices is between 0.3 and 2.0. In some embodiments, the difference between the highest and second-highest refractive indices is between 0.5 and 1.8. It should be noted that the aforementioned differences can be applied to other situations. For example, in some embodiments, the difference between the highest and lowest refractive indices among all refractive indices of the stacked layers may also be between 0.1 and 2.5, between 0.3 and 2.0, or between 0.5 and 1.8.

[0060] Since each of the superstructures 110A to 110L has a different refractive index, the refraction and absorption of the incident wave W are taken into account, thus improving not only the imaging quality but also the efficiency. Figures 3A to 3E Details for evaluating efficiency are provided. Furthermore, the thickness of the multilayer metastructures 110A to 110L can be reduced. In some embodiments, the aspect ratio of the multilayer metastructures 110A to 110L is less than 10, which makes manufacturing more feasible due to the relatively small aspect ratio. As for monolayer metastructures, if the refractive index of the monolayer metastructure is high, absorption may be quite significant, leading to poor efficiency. If the refractive index of the monolayer metastructure is low, the thickness of the monolayer metastructure may be thicker, and the imaging quality may be poor.

[0061] exist Figure 2A In a top view, each of the metastructures 110A has a circular shape. In some other embodiments, each of the metastructures 110A may have an elliptical shape when viewed from above. Each of the metastructures 110A includes a first layer 111A, a second layer 112A, and a third layer 113A. The second layer 112A is located between the first layer 111A and the third layer 113A. The first layer 111A has a first refractive index. The second layer 112A has a second refractive index. The first refractive index is different from the second refractive index. The third layer 113A has a third refractive index. In some embodiments, the second refractive index of the second layer 112A is greater than the first refractive index of the first layer 111A. In some embodiments, the first refractive index of the first layer 111A and the third refractive index of the third layer 113A are the same.

[0062] In some embodiments, the difference between the first refractive index of the first layer 111A and the second refractive index of the second layer 112A may be between 0.1 and 2.5, for example, 2.0. In some embodiments, the difference between the first refractive index of the first layer 111A and the second refractive index of the second layer 112A may be between 0.3 and 2.0, for example, 1.7. In some embodiments, the difference between the first refractive index of the first layer 111A and the second refractive index of the second layer 112A may be between 0.5 and 1.8, for example, 0.5.

[0063] The first layer 111A has a first thickness T1. The second layer 112A has a second thickness T2. The third layer 113A has a third thickness T3. In some embodiments, the first thickness T1 is different from the second thickness T2. In some embodiments, the first thickness T1 is greater than the second thickness T2. In some embodiments, the first thickness T1 and the third thickness T3 are the same. The sum of the first thickness T1, the second thickness T2, and the third thickness T3 may be less than 1 micrometer, for example, 700 nanometers (nm). The diameter D of each of the metastructures may be smaller than the wavelength range of interest, for example, 120 nanometers. The aspect ratio may be defined as (T1+T2+T3) / D, and, as previously mentioned, the aspect ratio may be less than 10.

[0064] Similar to Figure 2A ,exist Figures 2B to 2D In this process, each of the superstructures 110B to 110D comprises three layers; however, the shape of each of the superstructures 110B to 110D differs from the shape of each of the superstructures 110A. Figure 2B In a top-down view, each of the superstructures 110B has a rectangular shape. Figure 2C In the top view, each of the superstructures 110C has a pentagonal shape. Figure 2D In the middle, when viewed from above, each of the superstructures 110D has a hexagonal shape.

[0065] exist Figure 2E In Figure 2H, each of the superstructures 110E to 110H is a hollow structure. Figure 2E In the superstructure 110E, each of the superstructures is a cylinder with an internal cylindrical cavity; therefore, when viewed from above, each of the superstructures 110E has a circular shape with an internal circular hole. Figure 2F In the superstructure 110F, each of the superstructures is a cuboid with an internal cuboid cavity; therefore, when viewed from above, each of the superstructures 110F has a rectangular shape with an internal cuboid cavity. Figure 2G In Figure 2H, each of the superstructures 110G is a cylinder with an internal cuboid cavity; therefore, when viewed from above, each of the superstructures 110G has a circular shape with an internal rectangular hole. In Figure 2H, each of the superstructures 110H is a cuboid with an internal cylindrical cavity; therefore, when viewed from above, each of the superstructures 110H has a rectangular shape with an internal circular hole.

[0066] Furthermore, the number of layers in a superstructure can be more than three, such as... Figures 2I to 2L The metastructures shown are 110I to 110L. The overall thickness of the metastructure decreases as the number of layers increases. Figure 2I In the superstructure 110I, each of the superstructures comprises four layers 111I to 114I. Figure 2J In the middle, each of the superstructures 110J comprises five layers 111J to 115J. In Figure 2I as well as Figure 2J In this structure, odd-numbered layers (i.e., layers 111I, 113I or layers 111J, 113J, 115J) have the same refractive index, while even-numbered layers (i.e., layers 112I, 114I or layers 112J, 114J) have the same refractive index, and the refractive indices of the odd-numbered layers are different from those of the even-numbered layers. That is, each of the metastructures 110I and 110J has two different refractive indices arranged alternately.

[0067] exist Figure 2K as well as Figure 2L In this context, each of the metastructures 110K and 110L comprises five layers of 111K to 115K and five layers of 111L to 115L having more than two different refractive indices. For example, in... Figure 2K In this structure, the layer with the highest refractive index is the second highest layer, 112K, and the layers adjacent to the second highest layer, 112K (i.e., the highest layer, 111K, and the third highest layer, 113K) have different refractive indices. That is, each of the metastructures 110K has more than two refractive indices arranged irregularly. Figure 2L In this structure, the layer with the highest refractive index is the third-highest layer, 113L, and the layers adjacent to the third-highest layer, 113L (i.e., the second-highest layer, 112L, and the fourth-highest layer, 114L) have the same refractive index. Furthermore, the thickness of layer 112K differs from the thickness of the layers adjacent to layer 112K (i.e., layers 111K and 113K).

[0068] In summary, the shape of each metastructure (e.g., metastructures 110A to 110L), the thickness of each layer of each metastructure, the number of layers of each metastructure, the difference between refractive indices, the number of refractive indices, and the arrangement of layers with different refractive indices in the metastructure can be adjusted. In some embodiments, each metastructure may have a circular, elliptical, polygonal, or hollow polygonal shape when viewed from above. In some embodiments, the thickness of each stacked layer can be controlled. In some embodiments, the thickness of a layer with a lower refractive index may be greater than the thickness of a layer with a higher refractive index. In some embodiments, two or more layers may be present. In some embodiments, the total thickness of the metastructure decreases as the number of layers increases. In some embodiments, the difference between refractive indices is between 0.1 and 2.5. In some embodiments, each metastructure has two or more refractive indices. In some embodiments, layers with the same refractive index are staggered or arranged in an irregular manner.

[0069] Next, please refer to Figures 3A to 3E . Figures 3A to 3E The diagram schematically illustrates the relationship between the efficiency of several different metastructures and the wavelength of the incident wave. Criteria can be arbitrarily set to select a suitable metastructure. For example, the efficiency criterion can be set to be greater than a specific value to identify a suitable range and / or a specific value for the wavelength range of interest for various applications. For example, specific values ​​for the efficiency criterion can be set to be greater than 0.6, 0.8, 0.9, etc., but are not limited to these. Specific values ​​for the efficiency criterion can be set according to actual needs (e.g., the performance requirements of the metaoptical device). In some embodiments, the efficiency is consistently higher than 0.6 when the wavelength range of the incident wave is considered suitable, but is not limited to this. In some embodiments, the specific value of the incident wave wavelength can be determined based on the highest efficiency.

[0070] Available Figures 3A to 3C The effect of the difference in refractive index is evaluated. Specifically, this can be achieved by analyzing three metastructures with identical parameters, excluding the highest and second-highest refractive indices. Figures 3A to 3C For example, in Figure 3A The difference between the highest and second-highest refractive indices can be minimal, while... Figure 3C The difference between the highest and second-highest refractive indices can be the largest. For example, Figure 3A , Figure 3B , Figure 3C The difference between the highest and second-highest refractive indices can be approximately 0.5, 1.7, and 2.0, respectively, but is not limited to these values.

[0071] In some embodiments, Figures 3A to 3C middle, Figure 3A It has the widest applicable range of incident wave wavelengths. For example, if the standard is set to be greater than 0.6, then... Figures 3A to 3C The applicable wavelength range for the incident wave can be between approximately 450 nm and 620 nm, approximately 550 nm and 700 nm, and approximately 530 nm and 580 nm, respectively. On the other hand, if the incident wave has only a single incident wavelength, then... Figures 3A to 3C The specific wavelengths of the incident waves can be approximately 580 nanometers, 620 nanometers, and 690 nanometers, respectively.

[0072] Available Figure 3D as well as Figure 3E The influence of the stacking arrangement of metastructures is evaluated. Specifically, this can be achieved by analyzing two metastructures with identical parameters except for the layer with the highest refractive index. Figure 3D as well as Figure 3E For example, in Figure 3D The layer with the highest refractive index can be the second highest, while... Figure 3EThe layer with the highest refractive index can be the third highest layer, such as in... Figure 2K as well as Figure 2L The superstructures 110K and 110L shown are examples, but not limited to these. For example... Figure 3D as well as Figure 3E As shown, the applicable range of the incident wave wavelength differs from the specific numerical value of the incident wave wavelength. For example, if the standard is set to be greater than 0.6, then... Figure 3D as well as Figure 3E The applicable wavelength range for the incident wave can be between approximately 410 nm and 470 nm, and between approximately 500 nm and 600 nm, respectively. On the other hand, if the incident wave has only a single incident wavelength, then... Figure 3D as well as Figure 3E The specific wavelengths of the incident waves can be approximately 450 nanometers and 540 nanometers, respectively.

[0073] In summary, a suitable metastructure can be selected based on actual needs, such as the wavelength range of interest for various applications (e.g., visible light involves a wavelength range of approximately 400 nm to 700 nm), the required efficiency, etc.

[0074] Furthermore, in some embodiments, the geometry, size, and orientation of the metamaterials can be varied. Please refer to [reference needed]. Figures 4A to 4C To simplify, in Figures 4A to 4C The super-optical devices 100X to 100Z in the super-optical device 110X to 110Z have a three-layer structure, but are not limited to this. Figure 4A The geometric changes of the superstructure 110X are schematically shown. For example... Figure 4A As shown, each of the superstructures 110X has two sides with different included angles 115X. Figure 4B The dimensional variations of the superstructure 110Y are schematically illustrated. For example... Figure 4B As shown, the metamorphic structures 110Y gradually increase in size, such that the largest metamorphic structure 110Y is located in the peripheral region of the array of metamorphic structures 110Y. In some other embodiments, the largest metamorphic structure 110Y is located in the central region of the array of metamorphic structures 110Y, rather than in the peripheral region of the array of metamorphic structures 110Y. Figure 4C The schematic diagram illustrates the variation in the arrangement direction of the superstructure 110Z. For example... Figure 4C As shown, each of the superstructures 110Z may have the same geometry and size, but may have a spatially varying orientation. In some embodiments, each superstructure 110Z is rotated from the preceding superstructure 110Z in a column by the same amount (rotation angle change Δθ). In some embodiments, the rotation angle change Δθ may be a factor of 360 degrees, for example, the rotation angle change Δθ may be 15 degrees, 30 degrees, 45 degrees, etc.

[0075] By adjusting the geometry, size, and orientation of the metastructures (e.g., metastructures 110A to 110L and metastructures 110X to 110Z), the bending of the incident wave can be controlled in any way. Please refer to [reference needed]. Figure 4D . Figure 4D The incident angle θ with approximately 15 degrees is schematically shown. in The phase change of the incident wave. For example... Figure 4D As shown, the wavefront of the incident wave W can be modulated using the super-optical device 100 of this disclosure. It should be understood that the incident angle θ of the incident wave W... in This is merely an example. Phase correction can be achieved for incident waves W with almost any angle of incidence. In such cases, the super-optical device 100 acts as a phase corrector. The angle of incidence θ is relative to the central region of the optical system 1. in The angle θ may be relatively large in the peripheral region of optical system 1. Therefore, in order to correct for a large incident angle θ in The number of super-optical devices 100 disposed in the peripheral area of ​​the optical system 1 may be greater than the number of super-optical devices 100 disposed in the central area of ​​the optical system 1.

[0076] Next, please refer to Figures 5A to 5E This is to understand how the meta-optical device 100 acts as an aberration corrector. In detail, the meta-structure of the meta-optical device can correct aberrations; for example, the dispersion effect of the meta-structure can correct aberrations. Figures 5A to 5C The simulation process of aberration correction is illustrated schematically. Figure 5D as well as Figure 5E The results of aberration correction for the incident wave W are schematically shown. (The following text is incomplete and requires further context.) Figures 5A to 5EIn this simulation, an initial incident angle θ1 of the incident wave W is set to 35 degrees, and a corrected angle θ2 of the wave exiting the super-optical device 100 is set to 20 degrees, serving as the basis for the simulation, but this is merely an example. Phase correction can be achieved for incident waves W with virtually any incident angle and for any corrected angle. It should be understood that the camera 10 may also include one or more module lenses designed for aberration correction. Based on this disclosure, it is not necessary to design the module lenses in the camera 10 to correct all kinds of aberrations. In some embodiments, the super-optical device 100 may correct aberrations independently. In some embodiments, both the super-optical device 100 and the module lenses in the camera 10 may correct aberrations. For example, certain aberrations (such as higher-order aberrations, HOAs) are corrected by the super-optical device 100, while other aberrations are corrected by the modular lenses in the camera 10. This increases manufacturing flexibility. Additionally, manufacturing costs can be reduced, and the size of the modular lenses and / or the entire camera 10 can be reduced, thereby achieving miniaturization.

[0077] like Figure 5A As shown, the X-axis (x-axis position) represents a distance between the position and the midpoint, while the Y-axis (phase) represents a required amount for aberration correction. That is, for any arbitrary position, the required amount for aberration correction can be calculated and determined. Furthermore, the position can be determined and considered as a desired position. In some embodiments, the distance between the super-optical device and the image sensor is between 10 micrometers and 3 millimeters, for example, between 1 millimeter and 3 millimeters.

[0078] Figure 5B as well as Figure 5C yes Figure 5A The enlarged view shows the amount of aberration correction required at a location A and a location B. Figure 5A The position in the middle is shown in millimeters, while Figure 5B as well as Figure 5C The position is indicated in micrometers. Furthermore, the geometry, size, or orientation of the metastructure can be adjusted to assist in aberration correction. For example... Figure 5D as well as Figure 5E As shown, at the desired location (e.g., Figure 5A After determining the required amount of aberration correction at positions A and B, the super-optical device 100 can be positioned at the desired location to achieve the required aberration correction.

[0079] Figure 6This is a flowchart of a method 600 for correcting aberrations. Method 600 includes four steps 601 to 604. In step 601, method 600 includes calculating a desired amount for correcting aberrations. In step 602, method 600 includes determining a desired position of a meta-optical device (e.g., meta-optical device 100) disposed adjacent to an image sensor (e.g., image sensor 20), wherein a distance between the meta-optical device and the image sensor is between 10 micrometers and 3 millimeters. The meta-optical device includes an array of metastructures, and each metastructure includes multiple stacked layers, the stacked layers including at least a first layer having a first refractive index and a second layer having a second refractive index. The first refractive index and the second refractive index are different. In step 603, method 600 includes determining and / or adjusting the geometry, size, or orientation of the metastructures. In step 604, method 600 further includes setting the meta-optical device according to the desired amount and the desired position.

[0080] As previously described, this disclosure provides a meta-optical device. The meta-optical device includes an array of metastructures, each of which comprises multiple stacked layers with different refractive indices. By using different refractive indices, the refraction and absorption of incident waves are considered, thus improving both image quality and efficiency. Furthermore, the thickness of the multilayer metastructures can be reduced, resulting in greater manufacturing feasibility due to the relatively small aspect ratio. Moreover, the shape of each metastructure, the thickness of each layer of each metastructure, the number of layers in each metastructure, the difference in refractive indices, the number of refractive indices, and the arrangement of the layers with different refractive indices in the metastructure can be adjusted.

[0081] Furthermore, the meta-optics device provides two optical functions: phase correction and aberration correction. When used as a phase corrector, the phase of the incident wave can be modulated. When used as an aberration corrector, it can improve the performance of the image sensor and / or enhance image quality. The function of the meta-optics device can depend on its position relative to the image sensor. The distance between the meta-optics device and the image sensor can be less than 3 mm.

[0082] The foregoing overview of several embodiments enables those skilled in the art to better understand various aspects of this disclosure. Those skilled in the art will understand that this disclosure can be readily used as the basis for designing or modifying other processes and structures to achieve the same purpose or advantages as the embodiments described herein. Those skilled in the art will understand that such equivalent configurations do not depart from the spirit and scope of this disclosure, and various changes, substitutions, and modifications can be made to this disclosure without departing from its spirit and scope. Furthermore, features from various embodiments can be freely combined and used as long as they do not violate or conflict with the spirit of this disclosure.

Claims

1. A novel optical device disposed inside or above an image sensor, comprising: An array of multiple metastructures, each of which comprises multiple stacked layers, the stacked layers comprising at least a first layer having a first refractive index and a second layer having a second refractive index, wherein the first refractive index and the second refractive index are different; Wherein, when the super-optical device is disposed inside the image sensor, or when the super-optical device is disposed above the image sensor and the distance between the super-optical device and the image sensor is less than 10 micrometers, the super-optical device provides a phase correction function; When the super-optical device is positioned above the image sensor and the distance between the super-optical device and the image sensor is between 10 micrometers and 1 millimeter, the super-optical device provides the phase correction function and an aberration correction function. Specifically, when the super-optical device is positioned above the image sensor and the distance between the two devices is between 1 mm and 3 mm, the super-optical device provides the aberration correction function.

2. The super-optical device of claim 1, wherein the difference between the first refractive index and the second refractive index is between 0.5 and 1.

8.

3. The meta-optical device of claim 1, wherein the meta-structure comprises a dielectric material, and each of the meta-structures has an aspect ratio of less than 10.

4. The super-optical device of claim 1, wherein the stacked layer further comprises a third layer having a third refractive index, the third refractive index being different from the second refractive index, and the second layer being located between the first layer and the third layer, the second refractive index being greater than the first refractive index and the third refractive index, and the first refractive index being the same as the third refractive index.

5. The super-optical device of claim 1, wherein the stacked layer further comprises a third layer having a third refractive index, the third refractive index being different from the second refractive index, and the second layer being located between the first layer and the third layer, the first thickness of the first layer being different from the second thickness of the second layer, the first thickness and the third thickness of the third layer being greater than the second thickness, and the first thickness being the same as the third thickness.

6. The meta-optical device of claim 1, wherein, when viewed from above, each of the meta-structures has a circular, elliptical, polygonal, or hollow polygonal shape, the meta-structures are arranged in an array of rectangles or hexagons, and the meta-structures include different geometries, sizes, or orientations.

7. The super-optical device of claim 1, wherein the stacked layer further comprises multiple odd-numbered layers having the first refractive index and multiple even-numbered layers having the second refractive index.

8. An optical system, comprising: An image sensor, comprising: Multiple microlenses; and Multiple color filters are disposed below the microlens; and An advanced optical device is disposed inside or above the image sensor and above the color filter; The super-optical device includes an array of multiple super-structures, each of which includes multiple stacked layers, each stacked layer including a first layer having a first refractive index and a second layer having a second refractive index, wherein the first refractive index and the second refractive index are different. Wherein, when the super-optical device is disposed inside the image sensor, or when the super-optical device is disposed above the image sensor and the distance between the super-optical device and the image sensor is less than 10 micrometers, the super-optical device provides a phase correction function; When the super-optical device is positioned above the image sensor and the distance between the super-optical device and the image sensor is between 10 micrometers and 1 millimeter, the super-optical device provides the phase correction function and an aberration correction function. Specifically, when the super-optical device is positioned above the image sensor and the distance between the two devices is between 1 mm and 3 mm, the super-optical device provides the aberration correction function.

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