Metasurface lens and camera module

Abstract

The invention discloses a metasurface lens and a camera module, and belongs to the technical field of camera shooting. The metasurface lens comprises a transparent substrate and a plurality of groups of nano columns. At least two nano columns in each group of multiple groups of nano columns in the metasurface lens correspond to visible light of at least two wave bands, and the transmittance of each nano column to the visible light of the corresponding wave band is larger than the transmittance of visible light of other wave bands. Therefore, when visible light is incident on the metasurface lens, the transmittance of each nano-column to the visible light of the corresponding wave band is relatively high, and the transmittance of each nano-column to the visible light of other wave bands is relatively low. According to the metasurface lens, the energy of the visible light of different wavebands is high only in the corresponding nano-columns, and the energy of the visible light of different wavebands is low at other nano-columns, so that the interference between the visible light of different wavebands is effectively eliminated, and the phenomenon of poor chromatic aberration generated when the visible light penetrates through the metasurface lens is effectively eliminated.

Description

Technical Field

[0001] The present application relates to the field of camera technology, and in particular to a metasurface lens and a camera module. Background Art

[0002] Metasurface materials are materials that can directly process various elements of electromagnetic waves, such as amplitude, phase, polarization direction, and propagation direction, at the nanoscale. The lens designed from metasurface materials is called a superlens. The surface of the superlens is very flat and compact, and its nanoscale subwavelength structure can show excellent wavefront shaping performance. In addition, the weight and volume of the superlens are much smaller than traditional lenses, and the complex lens group structure can be simplified into one or several layers of nanostructures, which is conducive to the integrated application of lenses.

[0003] However, some current camera modules integrated with super lenses still suffer from chromatic aberration when shooting. Summary of the invention

[0004] The embodiment of the present application provides a metasurface lens and a camera module. The problem of poor color difference in camera module photography in the prior art can be solved. The technical solution is as follows:

[0005] In one aspect, a metasurface lens is provided, the metasurface lens comprising:

[0006] A transparent substrate and multiple groups of nanopillars;

[0007] The transparent substrate has a plurality of lens areas arranged in an array;

[0008] The plurality of groups of nanocolumns correspond to the plurality of lens regions one by one, each group of nanocolumns includes at least two nanocolumns, and each nanocolumn in each group of nanocolumns is fixedly connected to the transparent substrate in the corresponding lens region;

[0009] Among them, in a group of the nanocolumns, the at least two nanocolumns correspond to visible light of at least two bands, and the transmittance of each of the nanocolumns to the visible light of the corresponding band is greater than the transmittance to the visible light of other bands.

[0010] Optionally, in a group of the nanorods, the areas of the orthographic projections of the respective nanorods on the transparent substrate are different.

[0011] Optionally, in any two different groups of nanorods, the areas of the orthographic projections of two nanorods corresponding to the same wavelength band of visible light on the transparent substrate are the same.

[0012] Optionally, the shape of the orthographic projection of each of the nanocolumns on the transparent substrate is a rectangle; in any two different groups of nanocolumns, the orthographic projections of two nanocolumns corresponding to the same band of visible light on the transparent substrate are the same in length and width.

[0013] Optionally, the length of the orthographic projection of the nanocolumn on the transparent substrate ranges from 50 nanometers to 350 nanometers, and the width of the orthographic projection of the nanocolumn on the transparent substrate ranges from 50 nanometers to 350 nanometers.

[0014] Optionally, in a group of the nanocolumns, the transmittance of each nanocolumn to visible light in a corresponding band is greater than or equal to a first threshold, and the transmittance to visible light in other bands is less than or equal to a second threshold, and the first threshold is greater than the second threshold.

[0015] Optionally, each group of the nanocolumns includes four nanocolumns, the four nanocolumns are arranged in two rows and two columns, and the shape enclosed by the center lines of the orthographic projections of the four nanocolumns on the transparent substrate is a square.

[0016] Optionally, the heights of the nanorods are all the same.

[0017] Optionally, the height of the nanocolumns ranges from 200 nanometers to 700 nanometers.

[0018] Optionally, at least some of the multiple groups of nanocolumns have different angles between the length direction of the orthographic projection of the nanocolumns on the transparent substrate and a reference direction, and the reference direction is the direction of any coordinate axis in the target coordinate system of the metasurface lens, and the origin of the target coordinate system coincides with the center of the metasurface lens.

[0019] Optionally, the angle between the length direction of the orthographic projection of the nanocolumn on the transparent substrate and the reference direction satisfies the following relationship:

[0020]

[0021] Wherein, θ represents the angle between the length direction of the orthographic projection of the nanocolumn on the transparent substrate and the reference direction; τ represents the propagation phase value obtained when the visible light of each wavelength band passes through the corresponding nanocolumn; represents the phase of the nanocolumn after adjusting the visible light of the corresponding band; r represents the radial coordinate value of the nanocolumn on the metasurface lens; λ i represents the central wavelength of the visible light in the wavelength band corresponding to the nanorod; F represents the focal length of the metasurface lens.

[0022] On the other hand, a camera module is provided, the camera module comprising:

[0023] A camera and a metasurface lens, wherein the metasurface lens is any of the metasurface lenses given above.

[0024] The beneficial effects brought by the technical solution provided by the embodiment of the present application include at least:

[0025] A metasurface lens may include: a transparent substrate and multiple groups of nanocolumns. At least two nanocolumns in each group of nanocolumns in the multiple groups of nanocolumns in the metasurface lens are arranged to correspond to visible light of at least two bands, and the transmittance of each nanocolumn to the visible light of the corresponding band is greater than the transmittance of visible light of other bands. In this way, when visible light is incident on the metasurface lens, each nanocolumn has a high transmittance only to the visible light of the corresponding band, and a low transmittance to the visible light of other bands. That is, the visible light of different bands has a higher energy only in the corresponding nanocolumn, and a lower energy at other nanocolumns, thereby effectively eliminating the interference between visible light of different bands, and effectively eliminating the chromatic aberration phenomenon generated when visible light passes through the metasurface lens. And at least two bands cover the band of visible light, ensuring the utilization efficiency of visible light. In addition, after the metasurface lens is integrated in the camera module, the number of optical lenses in the camera module can be reduced, effectively reducing the volume of the camera module. Furthermore, the volume of a terminal device integrated with the camera module can be effectively reduced, and the weight of the terminal device can be ensured to be low. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 is a top view of a metasurface lens provided in an embodiment of the present application;

[0028] Figure 2 yes Figure 1 A local enlarged schematic diagram of area A;

[0029] Figure 3 yes Figure 1 A side view of a metasurface lens is shown;

[0030] Figure 4 is a partial schematic diagram of a top view of a metasurface lens;

[0031] Figure 5 It is a schematic structural diagram of a partially transparent substrate and a single nanocolumn in a metasurface lens provided in an embodiment of the present application;

[0032] Figure 6 This is a schematic diagram of the correspondence between visible light transmittance and wavelength band provided in an embodiment of the present application;

[0033] Figure 7 is a top view of a single nanopillar on a transparent substrate;

[0034] Figure 8 This is a diagram showing the effect of a metasurface lens provided in an embodiment of the present application focusing light;

[0035] Fig. 9 It is a structural schematic diagram of a camera module provided in an embodiment of the present application.

[0036] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0037] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below with reference to the accompanying drawings.

[0038] Please refer to Figure 1 , Figure 2 and Figure 3 , Figure 1 is a top view of a metasurface lens provided in an embodiment of the present application, Figure 2 yes Figure 1 A local enlarged schematic diagram of area A. Figure 3 yes Figure 1 A side view of a metasurface lens is shown. The metasurface lens 000 may include: a transparent substrate 100 and a plurality of groups of nanorods 200 .

[0039] The transparent substrate 100 in the metasurface lens 000 may have a plurality of lens regions 101 arranged in an array.

[0040] The multiple groups of nanopillars 200 in the metasurface lens 000 may correspond one-to-one to the multiple lens regions 101, each group of nanopillars 200 may include at least two nanopillars 200, and each nanopillar in each group of nanopillars 200 is fixedly connected to the transparent substrate 100 in the corresponding lens region 101 (each nanopillar is fixedly connected to the same side of the transparent substrate). For example, each lens region 101 may include at least two sub-lens regions corresponding one-to-one to at least two nanopillars 200, and the center of the orthographic projection of each nanopillar on the transparent substrate coincides with the center of the corresponding sub-lens region.

[0041] Among them, in a group of nanocolumns 200, at least two nanocolumns 200 can correspond to at least two bands of visible light (the at least two bands are different bands in visible light), and the transmittance of each nanocolumn 200 to the corresponding band of visible light can be greater than the transmittance of visible light in other bands. In the present application, at least two bands can be partial bands in the visible light band, or the at least two bands can cover the band of visible light. It should be noted that the following embodiments are schematically illustrated by taking the at least two bands covering the band of visible light as an example.

[0042] In the embodiment of the present application, at least two nanocolumns in each group of nanocolumns in the multiple groups of nanocolumns 200 in the metasurface lens 000 correspond to visible light of at least two bands, and the transmittance of each nanocolumn 200 to the visible light of the corresponding band is greater than the transmittance of visible light of other bands. In this way, when visible light is incident on the metasurface lens 000, each nanocolumn 200 has a higher transmittance to the visible light of the corresponding band only, and a lower transmittance to the visible light of other bands. That is, the visible light of different bands has higher energy only at the corresponding nanocolumn and lower energy at other nanocolumns, that is, the chromatic aberration effect caused by the visible light of other bands is eliminated, and then the interference between the visible light of different bands is effectively eliminated, and finally the chromatic aberration phenomenon caused by the visible light passing through the metasurface lens 000 is effectively eliminated. And at least two bands cover the band of visible light, ensuring the utilization efficiency of visible light. In addition, after the metasurface lens 000 is integrated into the camera module, the number of optical lenses in the camera module can be reduced, effectively reducing the volume of the camera module. The volume of the terminal device integrated with the camera module can also be effectively reduced, and the weight of the terminal device can be kept low.

[0043] In summary, the embodiment of the present application provides a metasurface lens, which may include: a transparent substrate and multiple groups of nanocolumns. At least two nanocolumns in each group of nanocolumns in the multiple groups of nanocolumns in the metasurface lens correspond to visible light of at least two bands, and the transmittance of each nanocolumn to the visible light of the corresponding band is greater than the transmittance of visible light of other bands. In this way, when visible light is incident on the metasurface lens, each nanocolumn has a high transmittance only to the visible light of the corresponding band, and a low transmittance to the visible light of other bands. That is, the visible light of different bands has a higher energy only in the corresponding nanocolumn, and a lower energy at other nanocolumns, thereby effectively eliminating the interference between visible light of different bands, and effectively eliminating the chromatic aberration phenomenon generated when visible light passes through the metasurface lens. And at least two bands cover the band of visible light, ensuring the utilization efficiency of visible light. In addition, after the metasurface lens is integrated in the camera module, the number of optical lenses in the camera module can be reduced, effectively reducing the volume of the camera module. Furthermore, the volume of a terminal device integrated with the camera module can be effectively reduced, and the weight of the terminal device can be ensured to be low.

[0044] Optional, please refer to Figure 4 , Figure 4 It is a partial schematic diagram of a top view of a metasurface lens. In a group of nanopillars 200, the areas of the orthographic projections of each nanopillar 200 on the transparent substrate 100 in the metasurface lens 000 are different. In this case, in a group of nanopillars 200, by setting the areas of the orthographic projections of each nanopillar 200 on the transparent substrate 100 in the metasurface lens 000 to be different, a group of nanopillars 200 can simultaneously regulate visible light. That is, when visible light is incident on the surface of the metasurface lens 000, a nanopillar 200 can have a higher transmittance of visible light in the band corresponding to this nanopillar and a lower transmittance of visible light in other bands, thereby regulating visible light through multiple groups of nanopillars 200 in the metasurface lens 000. For example, the number of visible light in at least two bands can be four, namely, the A1 band, the A2 band, the A3 band, and the A4 band. The number of nanocolumns in a group of nanocolumns 200 may be four, namely, nanocolumn B1, nanocolumn B2, nanocolumn B3 and nanocolumn B4. When visible light is incident on the metasurface lens, nanocolumn B1 has a higher transmittance to visible light in the A1 band, and a lower transmittance to visible light in the A2 band, A3 band and A4 band; nanocolumn B2 has a higher transmittance to visible light in the A2 band, and a lower transmittance to visible light in the A1 band, A3 band and A4 band; nanocolumn B3 has a higher transmittance to visible light in the A3 band, and a lower transmittance to visible light in the A1 band, A2 band and A4 band; nanocolumn B4 has a higher transmittance to visible light in the A4 band, and a lower transmittance to visible light in the A1 band, A2 band and A3 band.

[0045] In the embodiments of the present application, Figure 4 As shown, in any two different groups of nanorods 200, the areas of the orthographic projections of the two nanorods 200 corresponding to the visible light of the same wavelength band on the transparent substrate 100 are the same. In this case, by setting the areas of the orthographic projections of the two nanorods 200 corresponding to the visible light of the same wavelength band on the transparent substrate 100 in any two different groups of nanorods 200 to be the same, the influence of chromatic aberration when the visible light passes through the metasurface lens is eliminated, and the manufacturing process of the metasurface lens 000 is relatively simple.

[0046] Optional, please refer to Figure 3 and Figure 5 , Figure 5 It is a structural schematic diagram of a partial transparent substrate and a single nanocolumn in a metasurface lens provided in an embodiment of the present application. The shape of the orthographic projection of each nanocolumn 200 on the transparent substrate 100 in the metasurface lens 000 can be a rectangle. In any two different groups of nanocolumns 200, the length L of the orthographic projection of the two nanocolumns corresponding to the same band of visible light on the transparent substrate 100 is the same and the width W is the same. That is, in any two different groups of nanocolumns 200, when the orthographic projections of the two nanocolumns corresponding to the same band of visible light on the transparent substrate 100 are both rectangular, the length L of the two rectangles can be the same and the width W can be the same. In this case, by setting any two different groups of nanocolumns 200, the length L of the orthographic projection of the two nanocolumns 200 corresponding to the same band of visible light on the transparent substrate 100 is the same and the width W is the same. In this way, while further eliminating the influence of chromatic aberration generated when visible light passes through the metasurface lens 000, it is ensured that the manufacturing process of the metasurface lens is relatively simple. It should be noted that in other possible implementations, the shape of the nanocolumn can be an elliptical column, and its cross-sectional shape can be elliptical.

[0047] In the embodiments of the present application, Figure 5 As shown, the length L of the orthographic projection of the nanorod 200 in the metasurface lens 000 on the transparent substrate 100 can range from 50 nanometers to 350 nanometers; the width W of the orthographic projection of the nanorod 200 in the metasurface lens 000 on the transparent substrate 100 can range from 50 nanometers to 350 nanometers. That is, when the orthographic projection of the nanorod 200 in the metasurface lens 000 on the transparent substrate 100 is rectangular, the length of the rectangle can range from 50 nanometers to 350 nanometers, and the width of the rectangle can range from 50 nanometers to 350 nanometers.

[0048] Optionally, in a group of nanocolumns 200 in the metasurface lens 000, the transmittance of each nanocolumn to the visible light of the corresponding band is greater than or equal to the first threshold, and the transmittance to the visible light of other bands is less than or equal to the second threshold, and the first threshold may be greater than the second threshold. In this case, by setting the transmittance of each nanocolumn to the visible light of the corresponding band to be greater than or equal to the first threshold, the transmittance to the visible light of other bands is less than or equal to the second threshold. That is, the same first threshold and second threshold are set for different nanocolumns, ensuring that the efficiency of the visible light of each band passing through the metasurface lens 000 is basically the same, and the brightness of the light is basically the same. In addition, setting the first threshold to be greater than the second threshold makes each nanocolumn 200 have a higher transmittance to the visible light of the corresponding band, and a lower transmittance to the visible light of other bands, further effectively eliminating the chromatic aberration effect caused by the visible light of other bands, and then effectively eliminating the interference between the visible light of different bands, and finally effectively eliminating the chromatic aberration phenomenon caused by the visible light passing through the metasurface lens.

[0049] Taking the wavelength range of incident visible light from 450 nanometers to 650 nanometers as an example, the selection process of the nanorods 200 in the metasurface lens 000 is schematically described here:

[0050] First, determine that the shape of the nanocolumn is a rectangular column, and divide the wavelength range of visible light into four bands of visible light. For example, the four bands of visible light can be A1 band: 450 nanometers to 490 nanometers; A2 band: 500 nanometers to 540 nanometers; A3 band: 550 nanometers to 590 nanometers; A4 band: 600 nanometers to 650 nanometers. In the present application, the wavelength difference of each band can range from 20 nanometers to 100 nanometers, and the wavelength differences of different bands can be the same, different, or partially the same.

[0051] Then, the length of the rectangular column is selected to be in the range of 50 nanometers to 350 nanometers, and the width of the rectangular column is selected to be in the range of 50 nanometers to 350 nanometers. A certain step value is selected to simulate the transmittance values ​​of nanocolumns of different structural sizes in different bands, and establish an efficiency value database. For example, the certain step value can be 1 nanometer.

[0052] Afterwards, the transmittance of different nanocolumns to the corresponding bands is set to be greater than or equal to the first threshold, and the transmittance of visible light in other bands is less than or equal to the second threshold. In this way, a preliminary selection is made from the efficiency value database to select a plurality of four nanocolumn structures corresponding to four visible light bands. For example, the first threshold can be 10% and the second threshold can be 5%.

[0053] Finally, for the four types of nanocolumn structures, the efficiency values ​​are further compared and analyzed to obtain the lengths and widths of the four nanocolumn structures. For example, the length of the nanocolumn corresponding to the A1 band: 450 nanometers to 490 nanometers can be 76 nanometers, and the width can be 54 nanometers; the length of the nanocolumn corresponding to the A2 band: 500 nanometers to 540 nanometers can be 86 nanometers, and the width can be 72 nanometers; the length of the nanocolumn corresponding to the A3 band: 550 nanometers to 590 nanometers can be 100 nanometers, and the width can be 86 nanometers; the length of the nanocolumn corresponding to the A4 band: 600 nanometers to 650 nanometers can be 126 nanometers, and the width can be 100 nanometers. It should be noted that in the process of selecting nanocolumns in the form of rectangular columns, the heights of the various nanocolumns are the same. Please refer to Figure 6 , Figure 6 1 is a schematic diagram of the correspondence between visible light transmittance and wavelength provided in an embodiment of the present application. It can be seen from the figure that each nanorod in a group of nanorods has a higher transmittance to the visible light of the corresponding wavelength, while the transmittance to the visible light of other wavelengths is lower.

[0054] In the examples of this application, please refer to Figure 4 and Figure 7 , Figure 7 It is a top view of a single nanocolumn on a transparent substrate. Each group of nanocolumns 200 in the metasurface lens 000 may include four nanocolumns, and the four nanocolumns 200 may be arranged in two rows and two columns, and the shape formed by the center lines of the orthographic projections of the four nanocolumns 200 on the transparent substrate 100 is a square. The shape of the lens area 101 on the transparent substrate 100 may be square, and the shape formed by the center lines of the orthographic projections of the four nanocolumns 200 on the transparent substrate 100 may also be square, and the centers of the two squares may coincide. In the present application, the multiple groups of nanocolumns 200 in the metasurface lens 000 are arranged periodically, and each nanocolumn is also arranged periodically, and the range of the arrangement period of each nanocolumn may be: 200 nanometers to 500 nanometers, for example, the arrangement period may be 350 nanometers. In this way, the nanocolumns 200 in the metasurface lens 000 are arranged periodically, so that the imaging effect of the camera module after the light passes through the metasurface lens 000 is better.

[0055] Optional, such as Figure 5As shown, the height H of each nanocolumn 200 in the metasurface lens 000 can be the same. In the present application, when nanocolumns 200 of different heights are used in the metasurface lens 000, the metasurface lens 000 can achieve different transmittances for visible light. For example, in the embodiment of the present application, in order to ensure the transmittance of the nanocolumns 200 to visible light, the height H of the nanocolumns in the metasurface lens 000 can range from 200 nanometers to 700 nanometers. For example, the height of each nanocolumn 200 in the metasurface lens 000 can be selected to be 350 nanometers, and the embodiment of the present application does not make specific limitations on this. In addition, after the length L, width W and height H of the nanocolumns in the metasurface lens 000 are determined, the nanocolumns 200 can generally be made of at least one material selected from single crystal silicon, amorphous silicon and silicon nitride, and the transparent substrate 100 in the metasurface lens 000 can generally be made of visible light transparent materials such as glass or sapphire.

[0056] In the embodiments of the present application, Figure 7 As shown, the angle θ between the length direction of the orthographic projection of at least some of the multiple groups of nanocolumns 200 in the metasurface lens 000 on the transparent substrate 100 and the reference direction is different. The reference direction can be the direction of any coordinate axis in the target coordinate system of the metasurface lens 000, and the origin of the target coordinate system can coincide with the center of the metasurface lens 000. Among them, the orthographic projection of the nanocolumn 200 on the transparent substrate 100 is usually in the shape of a strip. For example, the shape of the orthographic projection of the nanocolumn 200 on the transparent substrate 100 can be a rectangle, and the long side direction of the orthographic projection is the length direction. It should be noted that the target coordinate system refers to a two-dimensional coordinate system constructed on the transparent substrate 100 of the metasurface lens 000 when designing the metasurface lens. The reference direction here can be the direction of the X-axis and the direction of the Y-axis in the two-dimensional coordinate system. It should also be noted that, please refer to Figure 8 , Figure 8 This is a diagram showing the effect of focusing light by a metasurface lens provided in an embodiment of the present application. The angle θ between the length direction of the orthographic projection of the nanocolumn 200 on the transparent substrate 100 and the reference direction is the steering angle of the nanocolumn 200. By rotating the nanocolumn 200 to change the steering angle, the size of the geometric phase obtained by the transmitted light can be changed, thereby achieving regulation of the incident light. In this way, the light emitted from the metasurface lens 000 can be converged to the same focal point, which is the focal point of the metasurface lens 000. In other words, the chromatic aberration caused by the light within the above-selected visible light band can be eliminated by the metasurface lens 000.

[0057] Optionally, the angle θ between the length direction of the orthographic projection of the nanorod 200 on the transparent substrate 100 in the metasurface lens 000 and the reference direction may satisfy the following relationship:

[0058]

[0059] Among them, θ represents the angle between the length direction of the orthographic projection of the nanorod on the transparent substrate in the metasurface lens and the reference direction; τ represents the propagation phase value obtained when the visible light of each band passes through the corresponding nanorod; represents the phase of the visible light in the corresponding band after the nanocolumn adjusts it; r represents the radial coordinate value of the nanocolumn on the metasurface lens; λ i Represents the central wavelength of visible light in the band corresponding to nanometers; F represents the focal length of the metasurface lens. It should be noted that the value of τ can be obtained while simulating the transmittance of the nanocolumns during the above-mentioned nanocolumn selection process. When calculating, the corresponding propagation phase value can be directly obtained based on the selected nanocolumns (the propagation phase value is related to the structural size of the nanocolumns). If the coordinate value of the center point of the orthographic projection of the nanocolumn in the metasurface lens on the transparent substrate in the two-dimensional coordinate system is (x, y), then the coordinate value of the center point of the orthographic projection of the nanocolumn on the transparent substrate and the radial coordinate value have the following relationship: r 2 =x 2 +y 2 The focal length value of the metasurface lens is set according to actual needs when designing the metasurface lens. For example, the focal length value is 10 mm.

[0060] For ease of description, the angle between the length direction of the orthographic projection of the nanorod 200 on the transparent substrate 100 in the metasurface lens 000 and the reference direction satisfies the following equations:

[0061] Defined as Formula 1.

[0062] The angle between the length direction of the orthographic projection of the nanorod 200 on the transparent substrate 100 in the metasurface lens 000 and the reference direction satisfies the following equations:

[0063] Defined as Formula 2.

[0064] Through the arrangement of the nanocolumns 200 on the transparent substrate 100, the phase of the nanocolumn after adjusting the visible light of the corresponding band can be calculated using Formula 2 according to the central wavelength of the visible light of the band corresponding to the nanocolumn, the radial coordinate value of the nanocolumn and the focal length value of the metasurface lens. Afterwards, the angle between the length direction of the orthographic projection of the nanocolumn on the transparent substrate in the metasurface lens and the reference direction can be calculated by using Formula 1 to combine the phase value obtained from Formula 2 and the known propagation phase value. It should be noted that the "﹢" and "﹣" in Formula 1 correspond to "right-handed" and "left-handed" circularly polarized incident light, respectively. When the angle θ ranges from 0 to π, the regulated phase can cover the range of 0 to 2π.

[0065] In summary, the embodiment of the present application provides a metasurface lens, which may include: a transparent substrate and multiple groups of nanocolumns. At least two nanocolumns in each group of nanocolumns in the multiple groups of nanocolumns in the metasurface lens correspond to visible light of at least two bands, and the transmittance of each nanocolumn to the visible light of the corresponding band is greater than the transmittance of visible light of other bands. In this way, when visible light is incident on the metasurface lens, each nanocolumn has a high transmittance only to the visible light of the corresponding band, and a low transmittance to the visible light of other bands. That is, the visible light of different bands has a higher energy only in the corresponding nanocolumn, and a lower energy at other nanocolumns, thereby effectively eliminating the interference between visible light of different bands, and effectively eliminating the chromatic aberration phenomenon generated when visible light passes through the metasurface lens. And at least two bands cover the band of visible light, ensuring the utilization efficiency of visible light. In addition, after the metasurface lens is integrated in the camera module, the number of optical lenses in the camera module can be reduced, effectively reducing the volume of the camera module. Furthermore, the volume of a terminal device integrated with the camera module can be effectively reduced, and the weight of the terminal device can be ensured to be low.

[0066] The present application also provides a camera module. Fig. 9 , Fig. 9 It is a structural schematic diagram of a camera module provided in an embodiment of the present application. The camera module may include: a camera 001 and a metasurface lens 000. Among them, the metasurface lens 000 may be any of the metasurface lenses given above. The chromatic aberration caused by the incident light can be eliminated by the metasurface lens, so that the imaging effect of the camera when imaging based on the light emitted from the metasurface lens is better. For example, the camera generally includes: a filter, a drive motor and an image sensor (not shown in the figure), the filter is arranged between the metasurface lens and the image sensor, and the drive motor can drive the metasurface lens to move along the central axis of the camera for focusing.

[0067] It should be noted that the transparent substrate in the metasurface lens only supports the multiple nanopillars, and does not regulate the light entering the metasurface lens. Therefore, the nanopillars in the metasurface lens can face the camera or face away from the camera relative to the transparent substrate.

[0068] The present application also provides a terminal device, which can be any display device with a camera function, such as a mobile phone, a laptop computer, a tablet computer, a camera, or a wearable device. The terminal device may include: a display panel and a camera module. The camera module may be Fig. 9 When the camera module includes a metasurface lens, it can ensure that the terminal device integrating the camera module is small in size and light in weight.

[0069] In the present application, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance. The term "plurality" refers to two or more than two, unless otherwise clearly defined.

[0070] The above description is only an optional embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A metasurface lens, characterized in that: include: A transparent substrate (100) and a plurality of groups of nanorods (200); The transparent substrate (100) has a plurality of lens areas (101) arranged in an array; The plurality of groups of nanocolumns (200) correspond one-to-one to the plurality of lens regions (101), each group of nanocolumns (200) comprises at least two nanocolumns, and each nanocolumn in each group of nanocolumns (200) is fixedly connected to the transparent substrate (100) in the corresponding lens region (101); Among them, in a group of the nanocolumns (200), the at least two nanocolumns correspond to visible light of at least two wavelength bands, and the transmittance of each of the nanocolumns to the visible light of the corresponding wavelength band is greater than the transmittance to the visible light of other wavelength bands.

2. The metasurface lens according to claim 1, characterized in that: In a group of the nanorods (200), the areas of the orthographic projections of the respective nanorods on the transparent substrate (100) are different.

3. The metasurface lens according to claim 2, characterized in that: In any two different groups of nanorods (200), the areas of the orthographic projections of the two nanorods corresponding to visible light in the same wavelength band on the transparent substrate (100) are the same.

4. The metasurface lens according to claim 3, characterized in that: The shape of the orthographic projection of each of the nanocolumns (200) on the transparent substrate (100) is a rectangle; in any two different groups of nanocolumns (200), the orthographic projections of two nanocolumns corresponding to visible light of the same wavelength band on the transparent substrate (100) are the same in length and width.

5. The metasurface lens according to claim 4, characterized in that: The length (L) of the orthographic projection of the nanocolumn (200) on the transparent substrate (100) ranges from 50 nanometers to 350 nanometers, and the width (W) of the orthographic projection of the nanocolumn (200) on the transparent substrate (100) ranges from 50 nanometers to 350 nanometers.

6. The metasurface lens according to any one of claims 1 to 5, characterized in that: In a group of the nanorods (200), the transmittance of each nanorod to visible light of a corresponding wavelength band is greater than or equal to a first threshold, and the transmittance to visible light of other wavelength bands is less than or equal to a second threshold, and the first threshold is greater than the second threshold.

7. The metasurface lens according to any one of claims 1 to 5, characterized in that: Each group of the nanocolumns (200) comprises four nanocolumns, the four nanocolumns are arranged in two rows and two columns, and the shape formed by the connecting lines of the centers of the orthographic projections of the four nanocolumns (200) on the transparent substrate (100) is a square.

8. The metasurface lens according to any one of claims 1 to 5, characterized in that: The heights (H) of the nanorods (200) are all the same.

9. The metasurface lens according to claim 8, characterized in that: The height (H) of the nanorods ranges from 200 nanometers to 700 nanometers.

10. The metasurface lens according to any one of claims 1 to 5, characterized in that: The angles (θ) between the length directions of the orthographic projections of at least some of the multiple groups of nanocolumns (200) on the transparent substrate (100) and a reference direction are different, and the reference direction is the direction of any coordinate axis in a target coordinate system of the metasurface lens, and the origin of the target coordinate system coincides with the center of the metasurface lens.

11. The metasurface lens according to claim 10, characterized in that: The angle (θ) between the length direction of the orthographic projection of the nanorod (200) on the transparent substrate (100) and the reference direction satisfies the following relationship: Wherein, θ represents the angle between the length direction of the orthographic projection of the nanocolumn on the transparent substrate and the reference direction; τ represents the propagation phase value obtained when the visible light of each wavelength band passes through the corresponding nanocolumn; represents the phase of the nanocolumn after adjusting the visible light of the corresponding band; r represents the radial coordinate value of the nanocolumn on the metasurface lens; λ i represents the central wavelength of the visible light in the wavelength band corresponding to the nanorod; F represents the focal length of the metasurface lens.

12. A camera module, characterized in that: include: A camera (001) and a metasurface lens (000) as claimed in any one of claims 1 to 11.

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