CN114994811B

CN114994811B - Super-surface lens, lens module, design method of lens module and electronic equipment

Info

Publication number: CN114994811B
Application number: CN202111504356.5A
Authority: CN
Inventors: 刘文钊; 翟羽佳
Original assignee: Honor Device Co Ltd
Current assignee: Honor Device Co Ltd
Priority date: 2021-12-10
Filing date: 2021-12-10
Publication date: 2023-05-30
Anticipated expiration: 2041-12-10
Also published as: CN114994811A

Abstract

The embodiment of the application provides a super-surface lens, a lens module, a design method of the lens module and electronic equipment, wherein the super-surface lens comprises: the unit structure comprises a first component part, a second component part positioned on the first side of the first component part and a third component part positioned on the second side of the first component part along a first direction, wherein the second component part and the third component part meet axisymmetric conditions about the first component part, and the volumes of the second component part and the third component part are smaller than those of the first component part, so that the super-surface lens is insensitive to polarization of incident light on the basis of realizing wide-band achromatism, and further the super-surface lens can have a better achromatism effect in daily use scenes.

Description

Super-surface lens, lens module, design method of lens module and electronic equipment

Technical Field

The present disclosure relates to the field of optical technologies, and particularly to a super-surface lens, a lens module including the super-surface lens, a design method of the lens module, and an electronic device including the lens module.

Background

With the development of optical technology, lens modules based on plastic lenses and CMOS sensors are increasingly applied to mobile terminal devices and wearable devices, and in order to adapt to the miniaturization development trend of mobile terminal devices and wearable devices, the mobile terminal devices and the wearable devices have strict volume and weight limitations, so that the lens modules based on plastic lenses and CMOS sensors face the trade-off of volume/weight and optical performance when applied to the mobile terminal devices and the wearable devices. Specifically, in the lens module, if more lenses are used, the optical performance of the lens module can be improved, but the volume and weight of the lens module can be increased, and if fewer lenses are used, the volume and weight of the lens module can be reduced, but the optical performance of the lens module can be reduced, so that the lens module is difficult to meet the increasing optical performance requirements of consumers on mobile terminal equipment and wearable equipment. Therefore, how to combine the volume/weight and the optical performance of the lens module has become a research focus for those skilled in the art.

Disclosure of Invention

The application provides a super-surface lens, a lens module comprising the super-surface lens, a design method of the lens module and electronic equipment, so that the volume/weight and the optical performance of the lens module are considered. .

In order to achieve the above object, the present application provides the following technical solutions:

in a first aspect, embodiments of the present application provide a super surface lens, including: the unit structures comprise a first component part, a second component part positioned on the first side of the first component part and a third component part positioned on the second side of the first component part along the first direction, wherein the second component part and the third component part meet axisymmetric conditions relative to the first component part, and the volumes of the second component part and the third component part are smaller than the volume of the first component part.

In the unit structure of the super-surface lens provided by the embodiment of the invention, the second component and the third component are located at two sides of the first component in the first direction, so that when the unit structure of the super-surface lens rotates by a first angle in the plane of the unit structure, the projection of the unit structure of the super-surface lens in the plane of the unit structure is not completely overlapped with the projection of the unit structure in the plane of the unit structure before the unit structure rotates, wherein the first angle is at least one angle in the range of 0-360 degrees, not including 0-360 degrees and 360 degrees, namely, at least one angle exists in the range of 0-360 degrees, not including 0-360 degrees, and the unit structure of the super-surface lens rotates by the angle, and the projection of the unit structure in the plane of the unit structure after the unit structure rotates is not completely overlapped with the projection of the unit structure in the plane of the unit structure before the unit structure rotates, so that the super-surface lens can be applied to wide-band achromatic imaging.

In addition, in the unit structure of the super-surface lens provided by the embodiment of the application, in the first direction, the second component and the third component meet the axisymmetric condition with respect to the first component, so that the super-surface lens is insensitive to polarization of incident light on the basis of realizing broadband achromatism by introducing axisymmetric design into the unit structure of the super-surface lens, and further the super-surface lens can have a better achromatism effect in daily use scenes.

In one implementation manner, the shape of the second component and the shape of the third component are the same, and the ratio of the dimensions of the same parts of the second component and the third component in each direction is in the range of 0.1-10, including the endpoint values, so that the second component and the third component meet the axisymmetric condition about the first component, and the process difficulty of the unit structure of the super-surface lens is reduced.

In another implementation manner, the first component, the second component and the third component are all square column structures, so that the process difficulty of the unit structure of the super-surface lens is further reduced, wherein the sizes of the first component, the second component and the third component are in nanometer level.

In yet another implementation, the first component has a length ranging from 50nm to 500nm, the second component has a length ranging from 50nm to 500nm, and the third component has a length ranging from 50nm to 500nm;

the width of the first component ranges from 50nm to 500nm, the width of the second component ranges from 50nm to 500nm, the width of the third component ranges from 50nm to 500nm, and the second direction is parallel to the plane where the plurality of unit structures are located and perpendicular to the first direction;

in a third direction, the height of the first component ranges from 300nm to 2000nm, the height of the second component ranges from 300nm to 2000nm, the height of the third component ranges from 300nm to 2000nm, and the third direction is perpendicular to a plane defined by the first direction and the second direction;

in the first direction, the distance between the first component and the second component ranges from 30nm to 200nm, and the distance between the first component and the third component ranges from 30nm to 200nm, so that the dimension and the process difficulty of the unit structure are considered on the basis of introducing axisymmetric design into the unit structure.

In yet another implementation, the first, second and third components are all cylindrical structures to further reduce the process difficulty of the unit structure of the super surface lens, wherein the dimensions of the first, second and third components are on the order of nanometers.

In yet another implementation, in the first direction, the second component and the third component are symmetrically located on both sides of the first component, in the first direction, a diameter of the first component is not smaller than a diameter of the second component, and a diameter of the first component is not smaller than a diameter of the third component.

In yet another implementation, the first component has a diameter ranging from 50nm to 500nm, the second component has a diameter ranging from 50nm to 500nm, and the third component has a diameter ranging from 50nm to 500nm;

in a third direction, the height of the first component ranges from 300nm to 2000nm, the height of the second component ranges from 300nm to 2000nm, the height of the third component ranges from 300nm to 2000nm, and the third direction is perpendicular to the plane where the plurality of unit structures are located;

In still another implementation manner, the plurality of unit structures are uniformly arranged, so that the super-surface lens can adjust phases of optical signals at positions of the unit structures by rotating directions of symmetry axes of the unit structures, thereby adjusting phases of different wavelengths, group delay and group delay dispersion in incident light, further making the super-surface lens insensitive to polarization states of the incident light, and adjusting group delay and group delay dispersion of the incident light, and achieving the purpose of eliminating chromatic aberration.

In yet another implementation, in the plane of the plurality of unit structures, the lateral distance between adjacent unit structures ranges from 50nm to 5000nm, and the longitudinal distance between adjacent unit structures ranges from 50nm to 5000nm, wherein the lateral direction and the longitudinal direction are two directions perpendicular to each other in a plane parallel to the plurality of unit structures.

In a second aspect, embodiments of the present application provide a lens module, including: refractive lens group and super surface lens group, wherein, refractive lens group includes at least one refractive lens, super surface lens group includes at least one super surface lens, super surface lens is the super surface lens that any one of above-mentioned provided, thereby utilizes refractive lens group to eliminate the partial chromatic aberration of jumbo size formation of image, utilizes super surface lens group to eliminate surplus partial chromatic aberration to make lens module also have better achromatism effect to jumbo size formation of image, and super surface lens group eliminates the required group delay of chromatic aberration part and is within its ability.

Because compared with the refractive lens, the weight and the volume of the super-surface lens are very small, the lens module provided by the embodiment of the application utilizes the super-surface lens group and the refractive lens group to realize chromatic aberration elimination of large-size imaging, and the lens module can have smaller weight and volume, so that the weight and the volume of the lens module are reduced, and the lens module is suitable for the development trend of miniaturization of mobile terminal equipment and wearable equipment when the lens module is applied to the mobile terminal equipment and the wearable equipment.

Therefore, the lens module provided by the embodiment of the application can give consideration to the weight/volume of the lens module and the optical performance of the lens module, and has smaller weight and volume on the basis of better optical performance.

In one implementation, the refractive lens group is located behind the super-surface lens group along the transmission direction of the optical signal in the lens module, so that the incident light passes through the super-surface lens group and then passes through the refractive lens group after entering the lens module.

In a third aspect, an embodiment of the present application provides a method for designing a lens module, for manufacturing the lens module provided in any one of the above, the method including:

calculating optical parameters of a refractive lens group, wherein the refractive lens group comprises at least one refractive lens, and the optical parameters of the refractive lens group comprise phase, group delay and group delay dispersion of the refractive lens group;

obtaining a difference optical parameter based on the optical parameter of the refractive lens group and a target optical parameter;

determining the number of the super-surface lenses in the super-surface lens group and the structural parameters of the unit structures of the super-surface lenses based on the difference optical parameters, and constructing the super-surface lens formed by a plurality of unit structures based on the structural parameters of the unit structures of the super-surface lenses in the super-surface lens group, wherein the structural parameters of the unit structures of the super-surface lenses comprise the geometric parameters of the unit structures of the super-surface lenses;

Simulating the super-surface lens group to obtain optical parameters of the super-surface lens group, wherein the optical parameters of the super-surface lens group comprise phase, group delay dispersion and light transmittance of the super-surface lens group;

and simulating a lens module formed by the refraction lens group and the super-surface lens group based on the optical parameters of the refraction lens group and the optical parameters of the super-surface lens group to obtain the optical parameters of the lens module.

The lens module designed by the design method of the lens module has smaller weight and volume and better optical performance, and can ensure that the electronic equipment has good optical performance when being applied to the electronic equipment such as mobile terminal equipment, wearable equipment and the like, and is favorable for the development of lightening and thinning of the electronic equipment on the basis of meeting the high optical performance requirement of a user.

In one implementation, determining the number of the super-surface lenses in the super-surface lens group and the structural parameters of the super-surface lenses based on the difference optical parameters includes:

determining the number of the super-surface lenses in the super-surface lens group based on the difference optical parameters;

Determining optical parameters of the single super-surface lens based on the difference optical parameters and the number of the super-surface lenses;

based on the optical parameters of the single super-surface lens, a database is queried to determine the structural parameters of the super-surface lens, wherein the optical parameters of the super-surface lens with different geometric parameters are stored in the database.

In a fourth aspect, an embodiment of the present application further provides an electronic device, where the electronic device includes the lens module provided in any one of the embodiments, so that the electronic device has good optical performance, and on the basis of meeting a requirement of a user for high optical performance, the electronic device is favorable to development of light and thin electronic devices.

Drawings

FIG. 1 is an application scenario diagram of a lens module applied to a mobile terminal device;

FIG. 2 is a schematic view of a lens module protruding from a mobile terminal device;

FIG. 3 is a schematic diagram showing the arrangement of unit structures in a super-surface lens according to an embodiment of the present disclosure;

FIG. 4 is a schematic structural view of a unit structure of a super-surface lens according to an embodiment of the present disclosure;

FIG. 5 is a schematic structural view of a unit structure of a super-surface lens according to another embodiment of the present disclosure;

FIG. 6 is a schematic structural diagram of a unit structure of a super-surface lens according to an embodiment of the present disclosure;

FIG. 7 is a schematic structural view of a unit structure of a super-surface lens according to another embodiment of the present disclosure;

FIG. 8 is a schematic diagram of a lens module according to an embodiment of the present disclosure;

FIG. 9 is a wavefront view of a lens module employing only refractive lenses;

FIG. 10 is a wavefront view of a lens module according to one embodiment of the present disclosure;

FIG. 11 is a graph of a point spread function of a lens module employing only refractive lenses;

FIG. 12 is a graph of a point spread function of a lens module according to one embodiment of the present disclosure;

FIG. 13 is a cross-sectional view of a point spread function of a lens module employing only refractive lenses;

FIG. 14 is a cross-sectional view of a point spread function of a lens module according to one embodiment of the present application;

FIG. 15 is a schematic diagram of a Modulation Transfer Function (MTF) of a lens module employing only refractive lenses;

FIG. 16 is a schematic diagram illustrating a modulation transfer function of a lens module according to an embodiment of the present disclosure;

FIG. 17 is a flow chart of a method for designing a lens module according to an embodiment of the present disclosure;

fig. 18 is a schematic structural diagram of an electronic device according to an embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. The terminology used in the following embodiments is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in the specification and the appended claims, the singular forms "a," "an," "the," and "the" are intended to include, for example, "one or more" such forms of expression, unless the context clearly indicates to the contrary. It should also be understood that in embodiments of the present application, "one or more" means one, two, or more than two; "and/or", describes an association relationship of the association object, indicating that three relationships may exist; for example, a and/or B may represent: a alone, a and B together, and B alone, wherein A, B may be singular or plural. The character "/" generally indicates that the context-dependent object is an "or" relationship.

Reference in the specification to "one embodiment" or "some embodiments" or the like means that a particular feature, structure, or characteristic described in connection with the embodiment is included in one or more embodiments of the application. Thus, appearances of the phrases "in one embodiment," "in some embodiments," "in other embodiments," and the like in the specification are not necessarily all referring to the same embodiment, but mean "one or more but not all embodiments" unless expressly specified otherwise. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless expressly specified otherwise.

The plurality of the embodiments of the present application refers to greater than or equal to two. It should be noted that, in the description of the embodiments of the present application, the terms "first," "second," and the like are used for distinguishing between the descriptions and not necessarily for indicating or implying a relative importance, or alternatively, for indicating or implying a sequential order.

For clarity and conciseness in the description of the following embodiments, a brief description of the related art will be given first:

superlens: the superlens is also called a supersurface lens, and is a thin lens (the thickness is in micron order) formed by regularly arranging sub-wavelength order unit structures, the phase control at different positions of transmitted light can be realized by adjusting parameters such as the size and/or the direction of the unit structures (resonant cavities), so that the functions of focusing and imaging are realized, specifically, at the position r, the phase introduced by the superlens is as follows:

group delay: group delay is also called group delay (i.e. the rate of change of the phase (phase shift) of a system at a certain frequency with respect to frequency, specifically, when a broadband signal passes through a linear element in a medium transmission path or device, the phase speed of each frequency spectrum component is different, the response of the component to each frequency spectrum component is different, and this causes disorder of the phase relationship, i.e. phase distortion, of the signal arriving at the receiving end due to the phase shift or delay of each frequency component. Phase distortion will cause the frequency modulated signal string noise to increase image signal distortion or to create intersymbol interference. Phase distortion is measured as the difference in time delay between a group of frequency components and is therefore referred to as group delay.

Group delay dispersion: group delay dispersion (group delay dispersion) is the change in group delay with frequency, or the differentiation of group delay versus angular frequency, and group delay dispersion (sometimes referred to as second order dispersion) of an optical element refers to the differentiation of group delay versus angular frequency, or the second order differentiation of spectral phase.

Aberration: the total chromatic aberration refers to a deviation from an ideal state of gaussian optics (first order approximation theory or paraxial rays) in an actual optical system, in which a result obtained by non-paraxial ray tracing does not coincide with a result obtained by paraxial ray tracing. Specifically, aberrations are mainly classified into spherical aberration, coma, curvature of field, astigmatism, distortion, chromatic aberration, and wave aberration.

Color difference: generally referred to as chromatic aberration, when white light is used for imaging, besides five monochromatic aberrations still generated by each monochromatic light, chromatic dispersion caused by different refractive indexes of different color lights can also cause different propagation light paths of different color lights, so that aberration caused by light path differences of different color lights can be displayed.

Point spread function (point spread function): in the optical system, when the input object is a point light source, the light field distribution of the output image is called a point spread function, which is also called a point spread function.

Modulation transfer function: also known as the spatial contrast transfer function (spatial contrast transfer function), the spatial frequency contrast sensitivity function (spatial frequencycontrast sensitivity function). The ability of the optical system to deliver various frequency sinusoid modulation levels is reflected as a function of spatial frequency.

As shown in fig. 1, fig. 1 is an application scenario diagram of a lens module applied to a mobile terminal device. In daily work or life, users often take pictures by using a lens module in a mobile terminal device (such as a mobile phone), for example, taking scenic pictures in life or taking book contents to be recorded in work. Since the photographing capability of the lens module in the mobile terminal device is generally proportional to the volume thereof, in order to improve the photographing performance of the mobile terminal device, the portion of the lens module in the mobile terminal device protruding from the rear case of the mobile terminal device is more and more, as shown in fig. 2.

The inventor researches that a super-surface lens (referred to as a super-lens for short) or an optical lens comprising the super-surface lens can be used to replace a refraction-based traditional lens module, however, the unit structure of the super-surface lens usually adopts a round or square design, so that aberration elimination of a single wavelength can only be realized, and the super-surface lens is not suitable for broadband imaging.

The inventor further researches that two components can be adopted in the super-surface lens, and in the process of rotating around the center of the super-surface lens, at least one position exists in a unit structure formed by the two components, the projection of the unit structure in the plane of the unit structure is not completely overlapped with the projection of the unit structure in the plane of the unit structure before the unit structure is rotated, so that the regulation and control of group delay and group delay dispersion in the unit structure are realized, the control of phases at different positions of transmitted light is realized, and further, the wide-band achromatic imaging is realized on the super-surface lens with the size of hundred micrometers. However, when the super-surface lens adopts a unit structure composed of two components, the super-surface lens is sensitive to the polarization of incident light, and can realize better achromatic effect only when the incident light is circularly polarized light. The sunlight and indoor illumination are both unpolarized light or partially polarized light, so that the super-surface lens cannot achieve better achromatic effect in daily use scenes.

In view of this, the embodiment of the application provides a super-surface lens and a lens module including the super-surface lens, so that the super-surface lens and the lens module including the super-surface lens can realize achromatic imaging on a wide band and can realize better achromatic effect in daily use scenes.

Specifically, as shown in fig. 3, the super-surface lens provided in the embodiment of the present application includes: as shown in fig. 4, the unit structure 10 includes a first component 11, a second component 12 located on a first side of the first component 11, and a third component 13 located on a second side of the first component 11 in a first direction X1, wherein the second component 12 and the third component 13 satisfy an axisymmetric condition with respect to the first component. Optionally, the volume of the second component and the third component is smaller than the volume of the first component.

It should be noted that, in the embodiment of the present application, the second component and the third component satisfying the axisymmetric condition with respect to the first component may include: the second component and the third component may be axisymmetric with respect to the first component, or may include that the second component and the third component are approximately axisymmetric with respect to the first component, which is not limited in this application, as the case may be.

Optionally, in an embodiment of the present application, the shape of the second component and the shape of the third component are the same, and the shape of the second component and the shape of the third component are the same as the shape of the first component, but this application is not limited thereto, and in other embodiments of the present application, the shape of the second component and the shape of the third component may be different from the shape of the first component, which is specific as the case may be.

The following describes a super surface lens provided in the embodiment of the present application, taking the shape of the second component and the shape of the third component as the same as the shape of the first component as an example.

Optionally, in an embodiment of the present application, the shape of the second component and the shape of the third component are the same, and the ratio of the dimensions of the same parts of the second component and the third component in each direction ranges from 0.1 to 10, including the end point values, so that the second component and the third component satisfy the axisymmetric condition with respect to the first component, and the process difficulty of the unit structure of the super-surface lens is reduced. Specifically, in one embodiment of the present application, the dimensions of the same portions of the second component and the third component in each direction include the dimensions of each of the second component and the third component in a part, and also include the dimensions between the second component and the first component and the dimensions between the third component and the first component.

In the above embodiment, when the ratio of the dimensions of the same portions of the second and third components in each direction is 1, the second and third components are axisymmetric with respect to the first component; the second and third components are approximately axisymmetric with respect to the first component when the ratio of the dimensions of the same portions of the second and third components in each direction is in the range of 0.1-10, except for other values of 1.

In particular, in one embodiment of the present application, the same portions of the second and third components have the same geometric dimensions in each direction such that the second and third components are axisymmetric with respect to the first component. However, the present application is not limited thereto, and in other embodiments of the present application, the second component and the third component may have similar geometric dimensions, so long as the ratio of the dimensions of the same portions of the second component and the third component in each direction is ensured to be in the range of 0.1-10, including the end point values.

The unit structure of the super surface lens provided in the embodiment of the present application will be described below with reference to the second component and the third component about the first component axis pair as an example.

Optionally, in an embodiment of the present application, the shapes of the first component, the second component and the third component are regular shapes, so as to reduce the process difficulty of the unit structure, but the present application is not limited thereto.

The unit structure of the super-surface lens provided in the embodiment of the present application will be described below by taking the shapes of the first component, the second component, and the third component as regular shapes as an example.

Specifically, in one embodiment of the present application, as further shown in fig. 4, the unit structure of the super-surface lens is composed of three nano square pillar structures, that is, the first component 11, the second component 12 and the third component 13 are all square pillar structures, and the sizes of the first component 11, the second component 12 and the third component 13 are in nano order, where the two smaller components of the second component 12 and the third component 13 are located on two sides of the larger component of the first component 11 in the first direction, and the larger component of the first component 11 satisfies the axisymmetric condition.

On the basis of the above embodiment, in one embodiment of the present application, continuing to refer to fig. 4, in the first direction X1, the second component 12 and the third component 13 are symmetrically located on both sides of the first component 11, in the first direction X1, the length l1 of the first component 11 is not smaller than the length l2 of the second component 12, and the length l1 of the first component 11 is not smaller than the length l3 of the third component 13, alternatively, the length l1 of the first component 11 is larger than the length l2 of the second component 12, and the length l1 of the first component 11 is larger than the length l3 of the third component 13, so that the volumes of the second component 12 and the third component 13 are smaller than the volumes of the first component 11; specifically, the length l1 of the first component 11 ranges from 50nm to 500nm, the length l2 of the second component 12 ranges from 50nm to 500nm, and the length l3 of the third component 13 ranges from 50nm to 500nm;

In the second direction Y1, the width w1 of the first component 11 is not smaller than the width w2 of the second component 12, and the width w1 of the first component 11 is not smaller than the width w3 of the third component 13, alternatively, the width w1 of the first component 11 is larger than the width w2 of the second component 12, and the width w1 of the first component 11 is larger than the width w3 of the third component 13, so that the volumes of the second and

third components

12 and 13 are smaller than the volume of the first component 11; specifically, the width w1 of the first component 11 ranges from 50nm to 500nm, the width w2 of the second component 12 ranges from 50nm to 500nm, the width w3 of the third component 13 ranges from 50nm to 500nm, and the second direction Y1 is parallel to the plane of the plurality of unit structures and perpendicular to the first direction X1;

in a third direction Z1, a value range of a height h1 of the first component 11 is 300nm to 2000nm, a value range of a height h2 of the second component 12 is 300nm to 2000nm, a value range of a height h3 of the third component 13 is 300nm to 2000nm, and the third direction Z1 is perpendicular to a plane in which the plurality of unit structures are located, that is, the third direction Z1 is perpendicular to a plane defined by the first direction X1 and the second direction Y1;

In the first direction X1, the value range of the distance g1 between the first component 11 and the second component 12 is 30nm to 200nm, and the value range of the distance g2 between the first component 11 and the third component 13 is 30nm to 200nm, so that the dimension and the process difficulty of the unit structure are considered on the basis of introducing axisymmetric design into the unit structure.

In another embodiment of the present application, as shown in fig. 5, the unit structure of the super-surface lens is composed of three nano-cylindrical structures, that is, the first component 11, the second component 12 and the third component 13 are all cylindrical structures, and the sizes of the first component 11, the second component 12 and the third component 13 are in nano-scale, wherein the two smaller components of the second component 12 and the third component 13 are located at two sides of the larger component of the first component 11 in the first direction, and the larger component of the first component 11 satisfies the axisymmetric condition.

On the basis of the above-described embodiments, in one embodiment of the present application, the second component 12 and the third component 13 are symmetrically located on both sides of the first component 11 in the first direction X1, and in the first direction X1, the diameter r1 of the first component 11 is not smaller than the diameter r2 of the second component 12, and the diameter r1 of the first component 11 is not smaller than the diameter r3 of the third component 13, alternatively, the diameter r1 of the first component 11 is larger than the diameter r2 of the second component 12, and the diameter r1 of the first component 11 is larger than the diameter r3 of the third component 13, so that the volumes of the second component 12 and the third component 13 are smaller than the volumes of the first component 11; specifically, in one embodiment of the present application, the diameter r1 of the first component 11 ranges from 50nm to 500nm, the diameter r2 of the second component 12 ranges from 50nm to 500nm, and the diameter r3 of the third component 13 ranges from 50nm to 500nm;

In a third direction Z1, a value of a height h1 of the first component 11 ranges from 300nm to 2000nm, a value of a height h2 of the second component 12 ranges from 300nm to 2000nm, a value of a height h3 of the third component 13 ranges from 300nm to 2000nm, and the third direction Z1 is perpendicular to a plane in which the plurality of unit structures are located;

In yet another embodiment of the present application, as shown in fig. 6, in the unit structure of the super surface lens, the first component 11 is in a cylindrical structure, the second component 12 and the third component 13 are in square cylindrical structures, and the dimensions of the first component 11, the second component 12 and the third component 13 are in nanometer order, wherein the two smaller components of the second component 12 and the third component 13 are located on two sides of the larger component of the first component 11 in the first direction, and the larger component of the first component 11 satisfies the axisymmetric condition.

In still another embodiment of the present application, as shown in fig. 7, in the unit structure of the super surface lens, the first component 11 is a square column structure, the second component 12 and the third component 13 are both cylindrical structures, and the dimensions of the first component 11, the second component 12 and the third component 13 are in nanometer order, wherein the two smaller components of the second component 12 and the third component 13 are located on both sides of the larger component of the first component 11 in the first direction, and the larger component of the first component 11 satisfies the axisymmetric condition.

In other embodiments of the present application, the first component, the second component, and the third component may also take other regular shapes, which is not limited in this application, as the case may be.

On the basis of any one of the above embodiments, in one embodiment of the present application, as shown in fig. 3, the plurality of unit structures 10 are uniformly arranged, so that the super-surface lens can adjust the phase of the optical signal at the position of each unit structure by rotating the direction of the symmetry axis of each unit structure, thereby adjusting the phase of different wavelengths in the incident light, the group delay and the group delay dispersion, so that the super-surface lens is insensitive to the polarization state of the incident light, and can adjust the group delay and the group delay dispersion of the incident light, and achieve the purpose of eliminating the chromatic aberration.

Optionally, based on the foregoing embodiment, in an embodiment of the present application, as further shown in fig. 3, in a plane where the plurality of unit structures are located, a value of a lateral distance d1 between adjacent unit structures ranges from 50nm to 5000nm, and a value of a longitudinal distance d2 between adjacent unit structures ranges from 50nm to 5000nm, where a lateral direction and a longitudinal direction are two directions perpendicular to each other in a plane parallel to the plurality of unit structures. It should be noted that, in the embodiment of the present application, the lateral distance and the longitudinal distance between adjacent unit structures may be the same or different, which is not limited in the present application, and the present application is specific as the case may be.

It should also be noted that, in the above embodiment, the symmetry axis of each unit structure may be rotated by 360 °, and the phase of the unit structure may be monotonically changed with the rotation angle thereof in the range of 0 to 180 °, for example, the phase of the unit structure may be gradually increased with the increase of the rotation angle thereof in the range of 0 to 180 °, or the phase of the unit structure may be gradually decreased with the increase of the rotation angle thereof in the range of 0 to 180 °.

In summary, the super-surface lens provided by the embodiment of the application can realize chromatic aberration elimination of broadband wavelength, is insensitive to the polarization state of incident light, and can be applied to daily use scenes.

From the foregoing, it can be seen that the unit structure of the super-surface lens provided in the embodiments of the present application can implement broadband achromatic imaging on a super-surface lens with a size of hundred micrometers. However, due to the height of the super-surface lens, the group delay introduced by the unit structure is limited, and only tens of femtoseconds are needed, so that the super-surface lens can not meet the group delay needed by large-size imaging, and can only be applied to a lens module for small-size imaging.

In view of this, an embodiment of the present application further provides a lens module, as shown in fig. 8, where the lens module includes a refractive lens group and a super-surface lens group, where the refractive lens group includes at least one refractive lens, and the super-surface lens group includes at least one super-surface lens, where the super-surface lens is a super-surface lens provided in any one of the embodiments, so that a portion of chromatic aberration of large-size imaging is eliminated by using the refractive lens group, and the rest of chromatic aberration is eliminated by using the super-surface lens group, so that the lens module also has a better achromatism effect on large-size imaging, and a group delay required by the super-surface lens group to eliminate the chromatic aberration portion is within a range of its capability.

In particular, in one embodiment of the present application, the super surface lens group includes at least one super surface lens, and the refractive lens group includes at least two refractive lenses, but the present application is not limited thereto, as the case may be.

Optionally, in the foregoing embodiment, in one embodiment of the present application, along a transmission direction of an optical signal in the lens module, the refractive lens group is located at a rear side of the super-surface lens group, that is, incident light passes through the super-surface lens group first and then passes through the refractive lens group after entering the lens module, but this is not limited thereto, and in other embodiments of the present application, along a transmission direction of an optical signal in the lens module, the refractive lens group may also be located at a front side of the super-surface lens group, that is, incident light passes through the refractive lens group first and then passes through the super-surface lens group after entering the lens module, as the case may be.

It should be noted that, in actual use, the lens module provided by the application can utilize the characteristic that the super-surface lens flexibly adjusts the light phase, so as to improve the performance of the lens module, and when designing the refractive lens group, select to use a smaller number of refractive lenses, and combine the super-surface lens group to eliminate the residual aberration, so as to achieve the purpose of reducing the volume of the lens module, thereby ensuring that the lens module provided by the application embodiment can maintain excellent optical performance while reducing the volume.

It should be further noted that, the number of the super surface lenses included in the super surface lens group and the number of the refractive lenses included in the refractive lens group are not limited, and are specifically determined according to the optical performance requirement and the cost requirement of the lens module and the weight and the volume requirement of the lens module on the scene to which the lens module is applied.

As shown in fig. 9 and fig. 10, fig. 9 shows a wavefront diagram of the lens module using only a refractive lens, and fig. 10 shows a wavefront diagram of the lens module provided in the embodiment of the present application, where the abscissa of fig. 9 and fig. 10 represents a transverse dimension of the lens module in a preset plane, a result of normalizing the abscissa of the lens module with a center of the lens module as an origin, and the ordinate represents a longitudinal dimension of the lens module in the preset plane, with the center of the lens module as the origin, and a result of normalizing the longitudinal dimension of the lens module, where the preset plane is parallel to an image plane of the lens module. As can be seen from fig. 9 and 10, if the lens module uses only refractive lenses, the maximum wavefront difference is 0.586 wavelengths, and the maximum wavefront difference of the lens module formed by combining the refractive lenses and the super surface lenses provided in the embodiment of the present application is 0.1 wavelengths, compared with the case that the lens module uses only refractive lenses, the maximum wavefront difference of the lens module provided in the embodiment of the present application is reduced from 0.586 wavelengths to 0.1 wavelengths, and the phase difference at the same position of the image plane is reduced by more than 80%.

As shown in fig. 11 and fig. 12, fig. 11 shows a point spread function diagram of the lens module using only a refractive lens, and fig. 12 shows a point spread function diagram of the lens module provided in the embodiment of the present application, where an abscissa is a transverse dimension in a plane where an imaging plane is located, and a longitudinal coordinate is a longitudinal dimension in a plane where the imaging plane is located, and a center of the imaging plane is located. As can be seen from fig. 11 and 12, compared with the case that the lens module only adopts the refractive lens, the lens module provided in the embodiment of the present application improves the focusing performance of the lens module, greatly suppresses the side lobe of the original focusing light spot, and realizes the beam focusing effect closer to the diffraction limit.

As shown in fig. 13 and 14, fig. 13 shows a cross-sectional view of a point spread function of the lens module using only a refractive lens, fig. 14 shows a cross-sectional view of a point spread function of the lens module provided in the embodiment of the present application, where fig. 13 is a cross-sectional view of a point spread function of fig. 11 at y=0, fig. 14 is a cross-sectional view of a point spread function of fig. 12 at y=0, and an abscissa is a lateral dimension of an imaging plane in a plane with a center of the imaging plane as an origin, and an ordinate is a relative irradiance at y=0. As can be seen from fig. 13 and 14, the lens module provided in the embodiment of the present application can more clearly see the improvement of the focusing effect compared with the case that the lens module only adopts the refractive lens.

Fig. 15 shows a schematic diagram of a Modulation Transfer Function (MTF) of the lens module using only a refractive lens, and fig. 16 shows a schematic diagram of a modulation transfer function of the lens module provided in the embodiment of the present application, wherein an abscissa is a spatial frequency in a unit of one millimeter, and an ordinate is a modulation transfer function, and different curves respectively represent a modulation transfer function of an S direction and a T direction of a diffraction limit, a modulation transfer function of an S direction and a T direction of a 1 ° incident angle, a modulation transfer function of an S direction and a T direction of a 2 ° incident angle, a modulation transfer function of an S direction and a T direction of a 3 ° incident angle, a modulation transfer function of an S direction and a T direction of a 4 ° incident angle, and a modulation transfer function of an S direction and a T direction of a 5 ° incident angle. As can be seen from fig. 15 and fig. 16, if the lens module only adopts the refractive lens, MTF of all fields of view except the zero field of view of the lens module at 120lp/mm is lower than 0.5, and the MTF of each field of view of the lens module provided by the embodiment of the present application is obviously improved, so that the effect of approaching the diffraction limit is achieved.

Therefore, the super-surface lens and the lens module comprising the super-surface lens provided by the embodiment of the application have good optical performance. Compared with the lens module which only adopts a refractive lens, the lens module provided by the embodiment of the application adopts a combination form of the super-surface lens and the refractive lens, and the volume and the weight are obviously reduced.

In addition, the embodiment of the present application further provides a method for designing a lens module, which is used for designing the lens module provided in any of the above embodiments, and specifically, as shown in fig. 17, the method for designing a lens module provided in the embodiment of the present application includes:

s1: calculating optical parameters of a refractive lens group, wherein the refractive lens group comprises at least one refractive lens, and the optical parameters of the refractive lens group comprise phase, group delay and group delay dispersion of the refractive lens group;

it should be noted that, in this embodiment, the refractive lens group may include one refractive lens or may include a plurality of refractive lenses, which is not limited in this application, and is specifically determined according to the optical performance requirement, the cost requirement, the weight requirement, the volume requirement, and other application requirements of the lens module. The more the number of refractive lenses included in the refractive lens group is, the higher the cost of the refractive lens group is, the larger the volume of the refractive lens group is, the higher the cost of the lens module is, and the larger the volume of the lens module is.

S2: obtaining a difference optical parameter based on the optical parameter of the refractive lens group and a target optical parameter;

In this embodiment, the target optical parameter is an optical parameter determined based on a design target, and optionally, in one embodiment of the present application, when the difference optical parameter is obtained based on the optical parameter of the refractive lens group and the target optical parameter, the difference between the actual optical parameter curve and the target optical parameter curve may be determined based on an actual optical parameter curve corresponding to the optical parameter of the refractive lens group and a target optical parameter curve corresponding to the target optical parameter, that is, in this embodiment, based on an optical parameter curve corresponding to the optical parameter of the refractive lens group and an optical parameter curve corresponding to the target optical parameter, to obtain the difference optical parameter.

S3: and determining the number of the super-surface lenses in the super-surface lens group and the structural parameters of the unit structures of the super-surface lenses based on the difference optical parameters, and constructing the super-surface lens formed by a plurality of unit structures based on the structural parameters of the unit structures of the super-surface lenses in the super-surface lens group, wherein the structural parameters of the unit structures of the super-surface lenses comprise the geometric parameters of the unit structures of the super-surface lenses.

Specifically, in one embodiment of the present application, determining the number of the super surface lenses in the super surface lens group and the structural parameters of the super surface lenses based on the difference optical parameters includes:

based on the optical parameters of the single super-surface lens, a database is queried to determine the structural parameters of the super-surface lens, wherein the optical parameters of the super-surface lens with different geometric parameters are stored in the database. However, the present application is not limited thereto, and in other embodiments of the present application, the structural parameters of the super surface lenses in the super surface lens group may be determined by other manners based on the difference optical parameters, where appropriate.

It should be noted that, in the embodiment of the present application, the super-surface lens group may include one super-surface lens, or may include a plurality of super-surface lenses, which is not limited in this application, and the present application is specifically limited as the case may be. Alternatively, in one embodiment of the present application, the super-surface lens group may include only one super-surface lens if a maximum optical parameter achievable by one super-surface lens is greater than the difference optical parameter, and the super-surface lens group may include at least two super-surface lenses if the maximum optical parameter achievable by one super-surface lens is less than the difference optical parameter.

Optionally, in an embodiment of the present application, the database is pre-established to shorten a time for determining structural parameters of the unit structures of the super surface lenses in the super surface lens group based on the difference optical parameters. Specifically, in one embodiment of the present application, the database establishment process includes:

simulating the unit structures of the super-surface lenses with different heights, widths, lengths and intervals to obtain the phase, group delay dispersion and light transmittance of the unit structures with different heights, widths, lengths and intervals so as to construct the corresponding relation between the structural parameters and the optical parameters of the unit structures with different structural parameters; and storing the corresponding relation between the structural parameters and the optical parameters of the unit structures with different structural parameters to obtain the database.

S4: and simulating the super-surface lens group to obtain optical parameters of the super-surface lens group, wherein the optical parameters of the surface lens group comprise phase, group delay dispersion, light transmittance and the like of the super-surface lens group.

S5: and simulating a lens module formed by the refraction lens group and the super-surface lens group based on the optical parameters of the refraction lens group and the optical parameters of the super-surface lens group to obtain the optical parameters of the lens module.

In addition, the embodiment of the application also provides electronic equipment, which comprises the lens module provided by any embodiment, so that the electronic equipment is light and thin and development is facilitated on the basis of having good optical performance and meeting the high optical performance requirement of a user. In particular, in some embodiments, the electronic device may be a cell phone, tablet, desktop, laptop, notebook, ultra-mobile personal computer (UMPC), handheld computer, netbook, personal digital assistant (Personal Digital Assistant, PDA), wearable electronic device, smart watch, or the like.

Optionally, in one embodiment of the present application, as shown in fig. 18, the electronic device may include a processor 110, an external memory interface 120, an internal memory 121, a universal serial bus (universal serialbus, USB) interface 130, a charge management module 140, a power management module 141, a battery 142, an antenna 1, an antenna 2, a mobile communication module 150, a wireless communication module 160, an audio module 170, a speaker 170A, a receiver 170B, a microphone 170C, an earphone interface 170D, a sensor module 180, keys 190, a motor 191, an indicator 192, a camera 193, a display 194, and a subscriber identity module (subscriber identification module, SIM) card interface 195, etc. The sensor module 180 may include a pressure sensor 180A, a gyro sensor 180B, an air pressure sensor 180C, a magnetic sensor 180D, an acceleration sensor 180E, a distance sensor 180F, a proximity sensor 180G, a fingerprint sensor 180H, a temperature sensor 180J, a touch sensor 180K, an ambient light sensor 180L, a bone conduction sensor 180M, and the like.

Specifically, in one embodiment of the present application, the lens module in the electronic device performs functions such as image capturing based on the light captured by the ambient light sensor 180L.

It is to be understood that the configuration illustrated in this embodiment does not constitute a specific limitation on the electronic apparatus. In other embodiments, the electronic device may include more or fewer components than shown, or certain components may be combined, or certain components may be split, or different arrangements of components. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

Alternatively, in one embodiment of the present application, the wireless communication function of the electronic device may be implemented by the antenna 1, the antenna 2, the mobile communication module 150, the wireless communication module 160, a modem processor, a baseband processor, and so on.

The antennas 1 and 2 are used for transmitting and receiving electromagnetic wave signals. Each antenna in the electronic device may be used to cover a single or multiple communication bands. Different antennas may also be multiplexed to improve the utilization of the antennas. For example: the antenna 1 may be multiplexed into a diversity antenna of a wireless local area network. In other embodiments, the antenna may be used in conjunction with a tuning switch.

The mobile communication module 150 may provide a solution for wireless communication including 2G/3G/4G/5G, etc. applied on an electronic device. The mobile communication module 150 may include at least one filter, switch, power amplifier, low noise amplifier (low noise amplifier, LNA), etc. The mobile communication module 150 may receive electromagnetic waves from the antenna 1, perform processes such as filtering, amplifying, and the like on the received electromagnetic waves, and transmit the processed electromagnetic waves to the modem processor for demodulation. The mobile communication module 150 can amplify the signal modulated by the modem processor, and convert the signal into electromagnetic waves through the antenna 1 to radiate. In some embodiments, at least some of the functional modules of the mobile communication module 150 may be disposed in the processor 110. In some embodiments, at least some of the functional modules of the mobile communication module 150 may be provided in the same device as at least some of the modules of the processor 110.

The modem processor may include a modulator and a demodulator. The modulator is used for modulating the low-frequency baseband signal to be transmitted into a medium-high frequency signal. The demodulator is used for demodulating the received electromagnetic wave signal into a low-frequency baseband signal. The demodulator then transmits the demodulated low frequency baseband signal to the baseband processor for processing. The low frequency baseband signal is processed by the baseband processor and then transferred to the application processor. The application processor outputs sound signals through an audio device (not limited to the speaker 170A, the receiver 170B, etc.), or displays images or video through the display screen 194. In some embodiments, the modem processor may be a stand-alone device. In other embodiments, the modem processor may be provided in the same device as the mobile communication module 150 or other functional module, independent of the processor 110.

The wireless communication module 160 may provide solutions for wireless communication including wireless local area network (wireless local area networks, WLAN) (e.g., wireless fidelity (wireless fidelity, wi-Fi) network), bluetooth (BT), global navigation satellite system (global navigation satellite system, GNSS), frequency modulation (frequency modulation, FM), near field wireless communication technology (near field communication, NFC), infrared technology (IR), etc. for application on an electronic device. The wireless communication module 160 may be one or more devices that integrate at least one communication processing module. The wireless communication module 160 receives electromagnetic waves via the antenna 2, modulates the electromagnetic wave signals, filters the electromagnetic wave signals, and transmits the processed signals to the processor 110. The wireless communication module 160 may also receive a signal to be transmitted from the processor 110, frequency modulate it, amplify it, and convert it to electromagnetic waves for radiation via the antenna 2.

In some embodiments, the antenna 1 and the mobile communication module 150 of the electronic device are coupled, and the antenna 2 and the wireless communication module 160 are coupled, so that the electronic device can communicate with the network and other devices through wireless communication technology. The wireless communication techniques may include the Global System for Mobile communications (global system for mobile communications, GSM), general packet radio service (general packet radio service, GPRS), code division multiple access (code division multiple access, CDMA), wideband code division multiple access (wideband code division multiple access, WCDMA), time division code division multiple access (time-division code division multiple access, TD-SCDMA), long term evolution (long term evolution, LTE), BT, GNSS, WLAN, NFC, FM, and/or IR techniques, among others. The GNSS may include a global satellite positioning system (global positioning system, GPS), a global navigation satellite system (global navigation satellite system, GLONASS), a beidou satellite navigation system (beidou navigation satellite system, BDS), a quasi zenith satellite system (quasi-zenithsatellite system, QZSS) and/or a satellite based augmentation system (satellite based augmentation systems, SBAS).

From the foregoing description of the embodiments, it will be apparent to those skilled in the art that, for convenience and brevity of description, only the above-described division of functional modules is illustrated, and in practical application, the above-described functional allocation may be implemented by different functional modules according to needs, i.e. the internal structure of the apparatus is divided into different functional modules to implement all or part of the functions described above.

In the several embodiments provided in this embodiment, it should be understood that the disclosed system, apparatus and method may be implemented in other manners. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of the modules or units is merely a logical functional division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted, or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.

The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

The foregoing is merely a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any changes or substitutions within the technical scope of the present disclosure should be covered in the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A super-surface lens, comprising: a plurality of unit structures including a first constituent portion, a second constituent portion located on a first side of the first constituent portion in a first direction, and a third constituent portion located on a second side of the first constituent portion, wherein the second constituent portion and the third constituent portion satisfy an axisymmetric condition with respect to the first constituent portion, and volumes of the second constituent portion and the third constituent portion are smaller than volumes of the first constituent portion; so that when the unit structure of the super-surface lens rotates by a first angle in the plane of the super-surface lens, the projection of the unit structure of the super-surface lens in the plane of the super-surface lens is not completely coincident with the projection of the unit structure of the super-surface lens in the plane of the super-surface lens before the unit structure is rotated.

2. The metasurface lens of claim 1, wherein the second component and the third component are identical in shape and the ratio of the dimensions of the identical portions of the second component and the third component in each direction is in the range of 0.1-10 inclusive.

3. The super surface lens as claimed in claim 1, wherein the first, second and third components are each square cylindrical structures and the dimensions of the first, second and third components are on the order of nanometers.

4. A super surface lens as claimed in claim 3, wherein in the first direction the second and third components are symmetrically located on either side of the first component, in the first direction the length of the first component is not less than the length of the second component and the length of the first component is not less than the length of the third component;

in a second direction, the width of the first component is not smaller than the width of the second component, and the width of the first component is not smaller than the width of the third component, and the second direction is parallel to the plane of the plurality of unit structures and perpendicular to the first direction.

5. The super surface lens as claimed in claim 4, wherein the length of said first component is in the range of 50nm to 500nm, the length of said second component is in the range of 50nm to 500nm, and the length of said third component is in the range of 50nm to 500nm;

in the first direction, the distance between the first component and the second component ranges from 30nm to 200nm, and the distance between the first component and the third component ranges from 30nm to 200nm.

6. The super surface lens as claimed in claim 1, wherein the first, second and third components are each cylindrical in structure and the dimensions of the first, second and third components are on the order of nanometers.

7. The super surface lens as claimed in claim 6, wherein the second and third components are symmetrically located on both sides of the first component in the first direction, and wherein the diameter of the first component is not smaller than the diameter of the second component and the diameter of the first component is not smaller than the diameter of the third component in the first direction.

8. The super surface lens as claimed in claim 7, wherein the diameter of said first component is 50nm to 500nm, the diameter of said second component is 50nm to 500nm, and the diameter of said third component is 50nm to 500nm;

9. The metasurface lens of claim 1, wherein the plurality of cell structures are uniformly arranged.

10. The metasurface lens of claim 9, wherein a lateral distance between adjacent cell structures in a plane of the plurality of cell structures is in a range of 50nm to 5000nm and a longitudinal distance between adjacent cell structures is in a range of 50nm to 5000nm, wherein the lateral and longitudinal directions are two directions perpendicular to each other in a plane parallel to the plurality of cell structures.

11. A lens module, comprising: refractive lens group and super surface lens group, wherein the refractive lens group comprises at least one refractive lens, the super surface lens group comprises at least one super surface lens, the super surface lens is the super surface lens of any one of claims 1-10.

12. The lens module of claim 11, wherein the refractive lens group is located behind the super surface lens group along a transmission direction of an optical signal in the lens module.

13. A method for designing a lens module according to claim 11 or 12, comprising:

14. The method of claim 13, wherein determining the number of the super-surface lenses in the super-surface lens group and the structural parameters of the super-surface lenses based on the difference optical parameters comprises:

15. An electronic device comprising the lens module of claim 11 or 12.