CN115032766A

CN115032766A - Optical system, imaging device comprising same and electronic equipment

Info

Publication number: CN115032766A
Application number: CN202210726532.8A
Authority: CN
Inventors: 郝成龙; 谭凤泽; 朱瑞; 朱健
Original assignee: Shenzhen Metalenx Technology Co Ltd
Current assignee: Shenzhen Metalenx Technology Co Ltd
Priority date: 2022-06-24
Filing date: 2022-06-24
Publication date: 2022-09-09

Abstract

The application provides an optical system, and relates to the technical field of optical imaging. The optical system includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens; at least one of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens is a super lens, and the rest are aspheric refractive lenses; all surfaces of the first aspheric refractive lens from the image side to the object side and the second aspheric refractive lens from the image side to the object side of the optical system comprise at least one aspheric surface, and the aspheric surface comprises an inflection point; the optical system further satisfies at least:

0.05mm≤d _ML ≤2mm；|f _ML i/f is more than or equal to 45; f is the focal length of the optical system; EPD is the optical system entrance pupil diameter; d _ML Is the super lens thickness; f. of _ML Is the superlens focal length. The optical system satisfies both a large aperture and a small overall system length.

Description

Optical system, imaging device comprising same and electronic equipment

Technical Field

The present application relates to the field of optical imaging technology, and in particular, to an optical system, and an imaging device and an electronic apparatus including the optical system.

Background

As the photographing demand of users increases, more and more electronic devices are mounted with imaging devices.

As the imaging quality of the imaging device is more and more required by users, the optical system of the existing imaging device is difficult to satisfy the requirements of large aperture and small overall length of the system.

Therefore, there is a need for an optical system that can simultaneously satisfy a large aperture and a small overall length of the system to promote miniaturization and weight saving of electronic equipment.

Disclosure of Invention

In order to solve the problem that the miniaturization of a projection system in the prior art is limited by the number of lenses and the volume of a lens, the embodiment of the application provides an optical system. The optical system comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens which are arranged from an object side to an image side in sequence;

wherein at least one of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens is a super lens, and the rest are aspheric refractive lenses;

in the optical system, all surfaces of a first aspheric refractive lens from an image side to an object side and a second aspheric refractive lens from the image side to the object side comprise at least one aspheric surface, and the aspheric surface comprises an inflection point;

the optical system further satisfies at least the following conditions:

0.05mm≤d _ML ≤2mm；

|f _ML |/f≥45；

f is the focal length of the optical system; EPD is the entrance pupil diameter of the optical system; d _ML Is the thickness of the superlens; f. of _ML Is the focal length of the superlens.

Optionally, the second lens is a super lens, and the rest lenses are aspheric refractive lenses; the first lens has positive focal power, and the object side surface of the first lens is a convex surface; a radius of curvature of an object-side surface of the third lens is positive; the fifth lens has positive focal power; the curvature radius of the object side surface of the sixth lens is positive.

Optionally, the first lens further satisfies:

wherein R is _1o Is a radius of curvature of an object-side surface of the first lens; f. of ₁ The focal length of the first lens at the central wavelength of the working waveband.

Optionally, the optical system further satisfies:

(V ₁ +V ₄ )/2-V ₃ >20；

wherein, V ₁ Is the abbe number of the first lens; v ₃ Is the abbe number of the third lens; v ₄ Is the abbe number of the fourth lens.

Optionally, the optical system further satisfies:

1.5<TTL/ImgH<1.8

wherein, TTL is the distance from the object side surface of the first lens to the image surface of the optical system; ImgH is the maximum imaging height of the optical system.

Optionally, the fourth lens further satisfies:

|R _4o |>R _4i ；

wherein R is _4o Is a radius of curvature of an object-side surface of the fourth lens; r is _4i Is a radius of curvature of an image-side surface of the fourth lens (40).

Optionally, a radius of curvature of an image-side surface of the seventh lens is greater than zero.

Optionally, the first lens further satisfies:

0.71≤f ₁ /f≤0.98；

wherein f is ₁ The focal length of the first lens at the central wavelength of the working waveband; f is the focal length of the optical system.

Optionally, the superlens includes a substrate layer and a nanostructure layer disposed on at least one side of the substrate layer, and the number of layers of the nanostructure layer is greater than or equal to 1;

each of the nanostructure layers includes periodically arranged nanostructures.

Optionally, the arrangement period of the nanostructures in any one of the nanostructure layers is greater than or equal to 0.3 λ c and less than or equal to 2 λ c;

and λ c is the central wavelength of the second lens working waveband.

Optionally, the height of the nanostructures in any one of the nanostructure layers is greater than or equal to 0.3 λ c and less than or equal to 5 λ c;

and λ c is the central wavelength of the second lens working waveband.

Optionally, any layer of the nanostructure layer comprises superstructure units arranged in an array;

the superstructure unit is a close-packed graph, and the nano structure is arranged at the vertex and/or the center of the close-packed graph.

Optionally, the extinction coefficient of the material of the substrate layer to the working waveband is less than 0.01.

Optionally, the extinction coefficient of the nanostructure material to the operating band is less than 0.01.

Optionally, the material of the substrate layer comprises fused silica, quartz glass, crown glass, flint glass, sapphire, crystalline silicon, amorphous silicon, and hydrogenated amorphous silicon.

Optionally, the nanostructured material comprises fused silica, quartz glass, crown glass, flint glass, sapphire, crystalline silicon, amorphous silicon, and hydrogenated amorphous silicon.

Optionally, the nanostructures are of a different material than the base layer.

Optionally, the nanostructures are the same material as the base layer.

Optionally, the shape of the nanostructure is a polarization insensitive structure.

Optionally, the polarization insensitive structure comprises a cylinder, a hollow cylinder, a circular hole, a hollow circular hole, a square cylinder, a square hole, a hollow square cylinder, and a hollow square hole.

Optionally, the second lens further comprises a filler;

the filler is filled between the nano structures;

and the extinction coefficient of the material of the filler to the working waveband is less than 0.01.

Optionally, an absolute value of a difference between the refractive index of the filler and the refractive index of the nanostructure is greater than or equal to 0.5.

Optionally, the filler comprises air, fused silica, quartz glass, crown glass, flint glass, sapphire, crystalline silicon, amorphous silicon, and hydrogenated amorphous silicon.

Optionally, the filler is of a different material than the base layer.

Optionally, the material of the filler is different from the material of the nanostructure.

Optionally, the second lens further comprises an antireflection film;

the antireflection film is arranged on one side, away from the nanostructure layer, of the substrate layer, and/or one side, away from the substrate layer, of the nanostructure layer.

Optionally, the wide-spectrum phase of the superstructure unit satisfies:

wherein r is the radial coordinate of the super lens; r is ₀ The distance from any point on the superlens to the center of the superlens; λ is the operating wavelength of the superlens.

Optionally, the superlens comprises at least two nanostructure layers;

wherein the nanostructures in any two adjacent nanostructure layers are coaxially arranged.

Optionally, the superlens comprises at least two nanostructure layers; and the nano structures in any adjacent nano structure layers are arranged in a staggered mode along the direction parallel to the substrate of the super lens.

Optionally, the phase of the superlens further satisfies:

wherein r is the distance from the center of the superlens to any nanostructure; λ is the operating wavelength of the superlens;

is any phase associated with the working wavelength of the superlens; (x, y) is the superlens mirror coordinates, f _ML Is the focal length of the superlens; a is _i And b _i Are real number coefficients.

Optionally, the second lens is applicable to the optical system provided in any of the above embodiments, and the method includes:

step S1, arranging a layer of structural layer material on the base layer;

step S2, coating photoresist on the structural layer material, and exposing a reference structure;

step S3, etching the periodically arranged nanostructures on the structural layer according to the reference structure to form the nanostructure layer;

a step S4 of disposing the filler between the nanostructures;

step S5, trimming the surface of the filler to make the surface of the filler coincide with the surface of the nano-structure.

Optionally, the method further comprises:

and step S6, repeating the steps S1 to S5 until the setting of all the nanostructure layers is completed.

Optionally, the apparatus comprises:

the optical system provided in any of the above embodiments; and a photosensitive element disposed on an image plane of the optical system.

Optionally, the apparatus includes the imaging device provided in the above embodiment.

The optical system provided by the embodiment of the application adopts at least one super lens and a plurality of aspheric refraction lenses to form a seven-piece optical system, and simultaneously, the F number is less than 2, the total length of the system is less than 6mm, and the miniaturization and the light weight of the optical system are promoted.

According to the superlens processing method provided by the embodiment of the application, the superlens structure with at least one nano-structure layer is realized through layered processing, the depth-to-width ratio of the nano-structure is improved, and the design freedom of the superlens is increased.

Drawings

The accompanying drawings are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the application and, together with the description, serve to explain the principles of the application.

Fig. 1 is a schematic diagram illustrating an alternative structure of an optical system provided in an embodiment of the present application;

FIG. 2 is a schematic diagram illustrating an alternative configuration of an optical system provided by an embodiment of the present application;

FIG. 3 is a schematic diagram illustrating an alternative configuration of an optical system provided by an embodiment of the present application;

FIG. 4 is a schematic diagram illustrating an alternative configuration of an optical system provided by an embodiment of the present application;

FIG. 5 is a schematic diagram illustrating an alternative configuration of an optical system provided by an embodiment of the present application;

FIG. 6 is a schematic diagram illustrating an alternative configuration of an optical system provided by an embodiment of the present application;

FIG. 7 is a schematic diagram illustrating an alternative configuration of an optical system provided by an embodiment of the present application;

FIG. 8 is a schematic diagram illustrating an alternative configuration of an optical system provided by an embodiment of the present application;

FIG. 9 is a schematic diagram illustrating an alternative configuration of an optical system provided in an embodiment of the present application;

FIG. 10 is a schematic diagram illustrating an alternative configuration of an optical system provided by an embodiment of the present application;

FIG. 11 is a schematic diagram illustrating an alternative configuration of an optical system provided by an embodiment of the present application;

FIG. 12 is a schematic diagram illustrating an alternative configuration of an optical system provided by an embodiment of the present application;

FIG. 13 is a schematic diagram illustrating an alternative configuration of an optical system provided by an embodiment of the present application;

FIG. 14 is a schematic diagram illustrating an alternative configuration of an optical system provided by an embodiment of the present application;

FIG. 15 is a schematic diagram illustrating an alternative configuration of an optical system provided by an embodiment of the present application;

FIG. 16 is a schematic diagram illustrating an alternative configuration of an optical system provided by an embodiment of the present application;

FIG. 17 is a schematic diagram illustrating an alternative configuration of an optical system provided by an embodiment of the present application;

FIG. 18 is a schematic diagram illustrating an alternative configuration of an optical system provided by an embodiment of the present application;

FIG. 19 is a schematic diagram illustrating an alternative configuration of an optical system provided by an embodiment of the present application;

FIG. 20 is a schematic diagram illustrating an alternative configuration of an optical system provided by an embodiment of the present application;

FIG. 21 is a schematic diagram illustrating an alternative configuration of an optical system provided by an embodiment of the present application;

FIG. 22 is a schematic diagram illustrating an alternative configuration of an optical system provided by an embodiment of the present application;

FIG. 23 is a schematic diagram illustrating an alternative configuration of an optical system provided by an embodiment of the present application;

FIG. 24 is a schematic diagram illustrating an alternative configuration of an optical system provided by an embodiment of the present application;

FIG. 25 is a schematic diagram illustrating an alternative arrangement of a superlens provided by an embodiment of the present application;

FIG. 26 is a schematic diagram illustrating an alternative arrangement of nanostructures in a superlens provided by an embodiment of the present application;

FIG. 27 is a schematic diagram illustrating an alternative arrangement of nanostructures in a superlens provided by an embodiment of the present application;

FIG. 28 is a schematic diagram illustrating an alternative arrangement of nanostructures in a superlens provided by an embodiment of the present application;

FIG. 29 is a schematic diagram illustrating yet another alternative arrangement of nanostructures in a superlens provided by an embodiment of the present application;

FIG. 30 is a schematic diagram illustrating yet another alternative arrangement of nanostructures in a superlens provided by an embodiment of the present application;

FIG. 31 is a schematic diagram illustrating an alternative arrangement of nanostructures in a superlens provided by an embodiment of the present application;

FIG. 32 is a schematic diagram illustrating an alternative arrangement of nanostructures in a superlens provided by an embodiment of the present application;

FIG. 33 is a schematic diagram illustrating an alternative arrangement of nanostructures in a superlens provided by an embodiment of the present application;

FIG. 34 is a schematic diagram illustrating an alternative arrangement of a superlens provided by an embodiment of the present application;

FIG. 35 is a schematic diagram illustrating an alternative arrangement of nanostructures in adjacent nanostructure layers, as provided by an embodiment of the present application;

FIG. 36 is a schematic diagram illustrating yet another alternative construction of a superlens provided by an embodiment of the present application;

FIG. 37 is an alternative phase diagram of a superlens provided by an embodiment of the present application;

FIG. 38 is a schematic diagram illustrating an alternative transmittance of a superlens provided by an embodiment of the present application;

FIG. 39 is a schematic diagram illustrating yet another alternative phase of a superlens provided by an embodiment of the present application;

FIG. 40 is a schematic diagram illustrating an alternative transmittance of a superlens provided by an embodiment of the present application;

FIG. 41 is a schematic flow chart diagram illustrating an alternative method for processing a superlens provided by an embodiment of the present application;

FIG. 42 is a schematic flow chart diagram illustrating yet another alternative method of fabricating a superlens provided by an embodiment of the present application;

FIG. 43 is a schematic flow chart diagram illustrating an alternative method for processing a superlens provided by an embodiment of the present application;

FIG. 44 is a schematic diagram illustrating phase modulation at different wavelengths for a superlens in the optical system of FIG. 1;

FIG. 45 shows an astigmatism diagram for the optical system shown in FIG. 1;

FIG. 46 shows a distortion plot of the optical system shown in FIG. 1;

FIG. 47 illustrates the broadband matching of the superlens in the optical system shown in FIG. 1;

FIG. 48 is a schematic diagram showing phase modulation of a superlens in the optical system of FIG. 2 at different wavelengths;

FIG. 49 shows an astigmatism diagram for the optical system shown in FIG. 2;

FIG. 50 shows a distortion plot of the optical system shown in FIG. 2;

FIG. 51 illustrates the broadband matching of the superlens in the optical system shown in FIG. 2;

FIG. 52 is a schematic diagram illustrating phase modulation at different wavelengths for a superlens in the optical system of FIG. 3;

FIG. 53 shows an astigmatism diagram for the optical system shown in FIG. 3;

FIG. 54 shows a distortion diagram of the optical system shown in FIG. 3;

FIG. 55 illustrates the broadband matching of the superlens in the optical system shown in FIG. 3;

FIG. 56 is a schematic diagram showing phase modulation at different wavelengths for a superlens in the optical system of FIG. 4;

FIG. 57 shows an astigmatism diagram for the optical system shown in FIG. 4;

FIG. 58 shows a distortion plot for the optical system shown in FIG. 4;

FIG. 59 illustrates the broadband matching of the superlens in the optical system shown in FIG. 4;

FIG. 60 is a schematic diagram illustrating phase modulation at different wavelengths for a superlens in the optical system of FIG. 5;

FIG. 61 shows an astigmatism diagram for the optical system shown in FIG. 5;

FIG. 62 shows a distortion plot of the optical system shown in FIG. 5;

FIG. 63 is a graph illustrating the broadband matching of the superlens in the optical system of FIG. 5;

FIG. 64 is a schematic diagram showing phase modulation at different wavelengths for a superlens in the optical system of FIG. 6;

FIG. 65 shows an astigmatism diagram for the optical system shown in FIG. 6;

FIG. 66 shows a distortion plot of the optical system shown in FIG. 6;

FIG. 67 illustrates the broadband matching of the superlens in the optical system shown in FIG. 6;

FIG. 68 is a schematic diagram showing phase modulation at different wavelengths for a superlens in the optical system of FIG. 7;

FIG. 69 shows an astigmatism diagram for the optical system shown in FIG. 7;

FIG. 70 shows a distortion plot of the optical system shown in FIG. 7;

FIG. 71 illustrates the broadband matching of the superlens in the optical system shown in FIG. 7;

FIG. 72 shows a phase modulation diagram for a superlens in the optical system of FIG. 8 at different wavelengths;

FIG. 73 shows an astigmatism diagram for the optical system shown in FIG. 8;

FIG. 74 shows a distortion plot for the optical system shown in FIG. 8;

FIG. 75 illustrates the broadband matching of the superlens in the optical system shown in FIG. 8;

FIG. 76 shows a schematic diagram of phase modulation at different wavelengths for a superlens in the optical system shown in FIG. 9;

FIG. 77 shows an astigmatism diagram for the optical system shown in FIG. 9;

FIG. 78 shows a distortion plot of the optical system shown in FIG. 9;

FIG. 79 illustrates the broadband matching of the superlens in the optical system shown in FIG. 9;

FIG. 80 is a schematic diagram illustrating phase modulation at different wavelengths for a superlens in the optical system of FIG. 10;

FIG. 81 shows an astigmatism diagram for the optical system shown in FIG. 10;

FIG. 82 shows a distortion plot of the optical system shown in FIG. 10;

FIG. 83 illustrates the broadband matching of the superlens in the optical system shown in FIG. 10;

FIG. 84 is a schematic diagram showing phase modulation at different wavelengths for a superlens in the optical system of FIG. 11;

FIG. 85 shows an astigmatism diagram for the optical system shown in FIG. 11;

FIG. 86 shows a distortion plot of the optical system shown in FIG. 11;

FIG. 87 illustrates the broadband matching of the superlens in the optical system shown in FIG. 11;

FIG. 88 is a schematic diagram illustrating phase modulation at different wavelengths for a superlens in the optical system of FIG. 12;

fig. 89 shows an astigmatism diagram of the optical system shown in fig. 12;

FIG. 90 shows a distortion plot for the optical system shown in FIG. 12;

FIG. 91 illustrates the broadband matching of the superlens in the optical system shown in FIG. 12;

FIG. 92 is a diagram illustrating phase modulation at different wavelengths for a superlens in the optical system of FIG. 13;

FIG. 93 shows an astigmatism diagram for the optical system shown in FIG. 13;

FIG. 94 shows a distortion plot for the optical system shown in FIG. 13;

FIG. 95 illustrates the broadband matching of the superlens in the optical system shown in FIG. 13;

FIG. 96 is a schematic diagram showing phase modulation at different wavelengths for a superlens in the optical system of FIG. 14;

FIG. 97 shows an astigmatism diagram for the optical system shown in FIG. 14;

FIG. 98 shows a distortion plot of the optical system shown in FIG. 14;

FIG. 99 illustrates the broadband matching of the superlens in the optical system shown in FIG. 14;

FIG. 100 is a diagram illustrating phase modulation at different wavelengths for a superlens in the optical system of FIG. 15;

FIG. 101 shows an astigmatism diagram for the optical system shown in FIG. 15;

FIG. 102 shows a distortion plot of the optical system shown in FIG. 15;

FIG. 103 illustrates the broadband matching of the superlens in the optical system shown in FIG. 15;

FIG. 104 is a schematic diagram showing phase modulation at different wavelengths for a superlens in the optical system of FIG. 16;

FIG. 105 shows an astigmatism diagram for the optical system shown in FIG. 16;

FIG. 106 shows a distortion plot of the optical system shown in FIG. 16;

FIG. 107 illustrates the degree of broadband matching of the superlens in the optical system shown in FIG. 16;

FIG. 108 is a schematic diagram showing phase modulation at different wavelengths for a superlens in the optical system of FIG. 17;

FIG. 109 shows an astigmatism diagram for the optical system shown in FIG. 17;

FIG. 110 shows a distortion plot for the optical system shown in FIG. 17;

FIG. 111 illustrates the broadband matching of the superlens in the optical system shown in FIG. 17;

FIG. 112 is a schematic diagram illustrating phase modulation at different wavelengths for a superlens in the optical system of FIG. 18;

fig. 113 shows an astigmatism diagram of the optical system shown in fig. 18;

FIG. 114 shows a distortion plot for the optical system shown in FIG. 18;

FIG. 115 illustrates the broadband matching of the superlens in the optical system shown in FIG. 18;

FIG. 116 is a diagram illustrating phase modulation at different wavelengths for a superlens in the optical system of FIG. 19;

FIG. 117 shows an astigmatism diagram for the optical system shown in FIG. 19;

FIG. 118 shows a distortion diagram of the optical system shown in FIG. 19;

FIG. 119 is a graph illustrating the broadband matching of the superlens in the optical system of FIG. 19;

FIG. 120 is a diagram illustrating phase modulation at different wavelengths for a superlens in the optical system of FIG. 20;

FIG. 121 shows an astigmatism diagram for the optical system shown in FIG. 20;

FIG. 122 shows a distortion diagram of the optical system shown in FIG. 20;

FIG. 123 illustrates the broadband matching of the superlens in the optical system shown in FIG. 20;

FIG. 124 shows a phase modulation diagram for a superlens at different wavelengths in the optical system of FIG. 21;

FIG. 125 shows an astigmatism diagram for the optical system shown in FIG. 21;

FIG. 126 shows a distortion plot for the optical system shown in FIG. 21;

FIG. 127 illustrates the broadband matching of the superlens in the optical system shown in FIG. 21;

FIG. 128 is a schematic diagram showing phase modulation at different wavelengths for a superlens in the optical system of FIG. 22;

FIG. 129 shows an astigmatism diagram for the optical system shown in FIG. 22;

FIG. 130 shows a distortion plot for the optical system shown in FIG. 22;

FIG. 131 illustrates the broadband matching of the superlens in the optical system shown in FIG. 22;

FIG. 132 is a schematic diagram showing phase modulation at different wavelengths for a superlens in the optical system of FIG. 23;

fig. 133 shows an astigmatism diagram of the optical system shown in fig. 23;

FIG. 134 shows a distortion plot of the optical system shown in FIG. 23;

FIG. 135 illustrates the broadband matching of the superlens in the optical system shown in FIG. 23;

FIG. 136 is a schematic diagram showing phase modulation at different wavelengths for a superlens in the optical system of FIG. 24;

FIG. 137 shows an astigmatism diagram for the optical system shown in FIG. 24;

FIG. 138 shows a distortion plot of the optical system shown in FIG. 24;

FIG. 139 illustrates the broadband matching of the superlens in the optical system shown in FIG. 24.

The reference numerals in the drawings denote:

10-a first lens; 20-a second lens; 30-a third lens; 40-a fourth lens; 50-a fifth lens; 60-a sixth lens; 70-a seventh lens; 80-diaphragm; 90-an infrared filter;

201-a base layer; 202-a nanostructure layer; 203-superstructure unit; 204-an anti-reflection film;

2021-nanostructures; 2022-fillers;

202 a-structural layer material; 205-photoresist; 206-reference structure.

Detailed Description

The present application will now be described more fully hereinafter with reference to the accompanying drawings, in which embodiments are shown. This application may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Like numbers refer to like elements throughout. Also, in the drawings, the thickness, ratio and size of the components are exaggerated for clarity of illustration.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, "a," "an," "the," and "at least one" do not denote a limitation of quantity, but rather are intended to include both the singular and the plural, unless the context clearly dictates otherwise. For example, "a component" means the same as "at least one component" unless the context clearly dictates otherwise. "at least one of" should not be construed as limited to the quantity "one". "or" means "and/or". The term "and/or" includes any and all combinations of one or more of the associated listed items.

Unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is the same as a meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

The meaning of "comprising" or "comprises" indicates a property, a quantity, a step, an operation, a component, a part, or a combination thereof, but does not exclude other properties, quantities, steps, operations, components, parts, or combinations thereof.

Embodiments are described herein with reference to cross-sectional views that are idealized embodiments. Thus, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, embodiments described herein should not be construed as limited to the particular shapes of regions as illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. For example, a region shown or described as flat may typically have rough and/or nonlinear features. Also, the acute angles shown may be rounded. Thus, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the precise shape of a region and are not intended to limit the scope of the claims.

Hereinafter, exemplary embodiments according to the present application will be described with reference to the accompanying drawings.

In the process of miniaturization of an optical system, the optical system using the traditional plastic lens is difficult to break through in thickness and large curvature due to the limitation of an injection molding process, so that the optical system with a seven-piece lens structure is difficult to break through in the thickness of each lens, the interval of each lens and the total length of the system. On the other hand, the plastic lens is made of more than ten kinds of materials, thereby limiting the degree of freedom in aberration correction of the optical system. At present, although the problems of chromatic aberration and the like are solved to some extent by glass-resin hybrid lenses, the miniaturization and the weight reduction of an optical system are still greatly hindered by an injection molding process. Nowadays, a great effort is made to reduce the total system length of an optical system by 1 mm. Since optical sensors in imaging devices, such as Charge Coupled Devices (CCD) and Complementary Metal Oxide Semiconductors (CMOS), have higher and higher pixels and larger sizes, it is more difficult to match optical systems with the higher pixels and the larger pixels and the smaller pixels to satisfy both large aperture and small overall length.

In a first aspect, embodiments of the present application provide an optical system, as shown in fig. 1 to 24, including a first lens 10, a second lens 20, a third lens 30, a fourth lens 40, a fifth lens 50, a sixth lens 60, and a seventh lens 70, which are arranged in order from an object side to an image side. At least one of the first lens 10, the second lens 20, the third lens 30, the fourth lens 40, the fifth lens 50, the sixth lens 60, and the seventh lens 70 is a super lens, and the rest are aspheric refractive lenses. And, all surfaces of the first aspheric refractive lens from the image side to the object side and the second aspheric refractive lens from the image side to the object side in the optical system include at least one aspheric surface including an inflection point. The optical system further satisfies at least the following formulas (1-1) to (1-3):

0.05mm≤d _ML ≤2mm；(1-2)

|f _ML |/f≥45；(1-3)

f is the focal length of the optical system; EPD is the entrance pupil diameter of the optical system; d is a radical of _ML Is the thickness of the superlens; f. of _ML Is the focal length of the superlens.

The optical system provided by the embodiment of the application enables the optical system with seven lenses to simultaneously satisfy the large aperture (namely, the small F number) and the small total length of the system by satisfying the arrangement mode. Wherein, the ratio of the absolute value of the super lens focal length to the whole optical system is more than or equal to 45, which is beneficial to enhancing the aberration correction capability of the optical system and improving the design freedom of the optical system. The aspheric surface comprises an inflection point, which is beneficial to reducing the effective radius of a first aspheric refractive lens from an image space to an object space and a second aspheric refractive lens from the image space to the object space in the optical system, thereby reducing the volume of the optical system and enabling the optical system to be better suitable for an imaging device with compact space.

The arrangement can enhance the imaging ability of the optical lens system, so that the optical lens system can be matched with the sensor in terms of pixel size, resolution or chief ray incidence angle, and the like, and has enough design freedom in the specification of the lens surface, thereby successfully meeting the requirements of various design specifications such as controlling the size of a lens and the like. It should be noted that fig. 1 to 24 only show some optional structures of the optical system provided in the embodiment of the present application. Fig. 1 to 24 only show the arrangement relationship of the lenses in the optical system provided by the embodiment of the present application, and the pitch between the lenses in the drawing is not the actual pitch between the lenses.

Further, in the optical system according to the embodiment of the present application, the second lens 20 is a super lens, and the remaining lenses are aspheric refractive lenses. And, wherein, the first lens 10 has positive focal power, and the object side surface of the first lens 10 is a convex surface; the radius of curvature of the object-side surface of the third lens 30 is positive; the fifth lens 50 has positive optical power; the curvature radius of the object-side surface of the sixth lens 60 is positive. The powers of the fourth lens 40 and the seventh lens 70 may be selected according to the design requirements of the optical system.

According to the embodiment of the present application, further, the fourth lens 40 satisfies formula (2):

|R _4o |>R _4i ；(2)

wherein R is _4o Is the radius of curvature of the object-side surface of the fourth lens 40; r is _4i Is the radius of curvature of the image-side surface of the fourth lens 40. R _no And R _ni The curvature radii of the object side surface and the image side surface of each lens in the optical system are expressed, wherein n is the lens arrangement order from the object side to the image side, o is the object side, and i is the image side.

According to the embodiment of the present application, optionally, a radius of curvature of the image-side surface of the seventh lens 70 is larger than zero.

According to an embodiment of the present application, optionally, the first lens 10 further satisfies formula (3):

wherein R is _1o Is the radius of curvature of the object-side surface of the first lens 10; f. of ₁ Is the focal length of the first lens 10 at the center wavelength of the operating band. Satisfying the arrangement of equation (3) is advantageous to ensure that the optical system has sufficient positive refractive power, thereby facilitating further compression of the overall length of the optical system.

In an alternative implementation, the optical system provided in the embodiment of the present application further satisfies formula (4):

(V ₁ +V ₄ )/2-V ₃ >20；(4)

wherein, V ₁ Is the abbe number of the first lens (10); v ₃ Abbe number of the third lens 30; v ₄ Is the abbe number of the fourth lens 40. Therefore, the correction of the imaging chromatic aberration by the optical system can be further optimized.

In yet another alternative embodiment of the present application, the optical system further satisfies formula (5):

1.5<TTL/ImgH<1.8；(5)

wherein TTL is a distance from an object-side surface of the first lens element 10 to an image plane of the optical system (also referred to as Total Tracking Length in this application); ImgH is the maximum imaging height of the optical system. The maximum imaging height is one-half of the total diagonal length of the effective sensing area of the electron-sensitive element. The arrangement is beneficial to achieving balance on miniaturization of the optical system and matching degree of the optical system and the photosensitive element, and therefore production difficulty is reduced.

More advantageously, the first lens 10 also satisfies:

0.71≤f ₁ /f≤0.98；(6)

wherein f is ₁ The focal length of the first lens 10 at the center wavelength of the operating band; f is the focal length of the optical system. Therefore, enough positive refractive power can be provided, and the total length of the optical system can be effectively reduced.

It is understood that, in the optical system provided in the embodiments of the present application, the material of the aspheric refractive lens may be optical glass, such as crown glass, flint glass, quartz glass, etc.; and various optical plastics such as APL5514, OKP4HT and the like can be adopted. Preferably, the aspheric refractive lens is made of optical plastic. The aspheric refraction lens is made of optical plastic and can realize the mass production of aspheric lenses at low cost in large batch by injection molding.

Next, a superlens (i.e., the second lens 20) provided in an embodiment of the present application is described with reference to fig. 25 to 43.

In particular, a superlens is a specific application of a supersurface that modulates phase, amplitude, and polarization of incident light by periodically arranged sub-wavelength-sized nanostructures.

FIG. 25 is a schematic diagram illustrating an alternative structure of a superlens provided by an embodiment of the present application. Referring to fig. 25, the superlens provided by the embodiment of the present application includes a substrate layer 201 and a nanostructure layer 202 disposed on at least one side of the substrate layer 201, and the number of layers of the nanostructure layer 202 is greater than or equal to 1. Each of the at least one nanostructure layer 202 includes periodically arranged nanostructures 2021.

According to an embodiment of the present application, optionally, in any of the at least one nanostructure layer 202, the arrangement period of the nanostructures 2021 is greater than or equal to 0.3 λ _c And is less than or equal to 2 lambda _c (ii) a Wherein λ is _c The center wavelength of the superlens operating band.

Optionally, according to an embodiment of the present application, the height of the nanostructures 2021 in any of the at least one nanostructure layer 202 is greater than or equal to 0.3 λ _c And is less than or equal to 5 lambda _c (ii) a Wherein λ is _c The center wavelength of the superlens operating band.

Fig. 26 and 27 show perspective views of nanostructures 2021 in any of the nanostructure layers 202 of the second lens 20. Alternatively, fig. 26 is a cylindrical structure. Alternatively, the nanostructures 2021 in fig. 27 are square cylindrical structures. Optionally, as shown in fig. 25 and 27, the superlens further includes a filler 2022, the filler 2022 is filled between the nanostructures 2021, and an extinction coefficient of a material of the filler 2022 to an operating band is less than 0.01. Optionally, the filler 2022 comprises air or other material that is transparent or translucent in the operating band. According to an embodiment of the present application, the absolute value of the difference between the refractive index of the material of the filler 2022 and the refractive index of the nanostructures 2021 should be greater than or equal to 0.5. When the superlens provided by the embodiment of the present application has at least two nanostructure layers 202, the filler 2022 in the nanostructure layer 202 farthest from the substrate layer 201 may be air.

In some alternative embodiments of the present application, as shown in fig. 28 to 30, any one of the at least one nanostructure layer 202 includes superstructure units 203 arranged in an array. The superstructure unit 203 is a close-packable pattern with nanostructures 2021 disposed at the vertices and/or center of the close-packable pattern. In the embodiments of the present application, the close-packable patterns refer to one or more patterns that can fill the entire plane without gaps and without overlapping.

As shown in fig. 28, according to an embodiment of the present application, the superstructure units may be arranged in a fan shape. As shown in fig. 29, according to an embodiment of the present application, the superstructure units may be arranged in an array of regular hexagons. Further, as shown in fig. 30, according to an embodiment of the present application, the superstructure units 203 may be arranged in a square array. Those skilled in the art will recognize that the superstructure units 203 included in the nanostructure layer 202 may also include other forms of array arrangements, and all such variations are within the scope of the present application. It is understood that in some alternative embodiments, the period of the superstructure unit 203 is greater than or equal to 0.3 λ _c And is less than or equal to 2 lambda _c (ii) a Wherein λ is _c The center wavelength of the superlens operating band.

Optionally, the embodiments of the present application provideThe wide spectrum phase of the superstructure unit 203 and the working wave band of the superlens further satisfy:

wherein r is the radial coordinate of the superlens; r is ₀ Is any point on the superlens; λ is the operating wavelength.

Illustratively, the nanostructures 2021 provided by the embodiments of the present application may be polarization-independent structures, which exert a propagation phase on incident light. According to the embodiment of the present application, as shown in fig. 31, 32, and 33, the nanostructure 2021 may be a positive structure or a negative structure. For example, the shape of the nanostructures 2021 includes cylinders, hollow cylinders, square prisms, hollow square prisms, and the like.

More advantageously, as shown in fig. 34, the second lens 20 provided by the embodiment of the present application includes at least two nanostructure layers 202. Alternatively, as shown in (a) of fig. 35, the nanostructures 2021 in adjacent nanostructure layers of the at least two layers of nanostructures 202 are coaxially aligned. The coaxial arrangement means that the arrangement periods of the nanostructures 2021 in the adjacent two nanostructure layers 202 are the same; or the axes of the nanostructures 2021 at the same position in two adjacent nanostructure layers coincide. Alternatively, as shown in (b) of fig. 35, the nanostructures 2021 in adjacent ones of the at least two layers of nanostructures 202 are misaligned in a direction parallel to the base 201 of the superlens. The arrangement mode is beneficial to breaking through the limitation of the processing technology on the aspect ratio of the nano structure in the super lens, thereby realizing higher design freedom. Figure 34 shows a perspective view of an alternative three-layer nanostructure layer. According to the embodiment of the present application, the shapes, sizes or materials of the nanostructures 2021 in the adjacent nanostructure layers 202 may be the same or different.

Exemplarily, a in fig. 31 to d in fig. 31 show that the shape of the nanostructure 2021 includes a cylinder, a hollow cylinder, a square column, and a hollow square column, respectively, and the nanostructure 2021 is filled with the filler 2022 therearound. In fig. 31, the nanostructure 2021 is disposed at the center of the superstructure unit 203 of a regular quadrangle. In alternative embodiments of the present application, a in fig. 32 to d in fig. 32 show that the shape of the nanostructure 2021 includes a cylinder, a hollow cylinder, a square column, and a hollow square column, respectively, and the nanostructure 2021 is free of the filler 2022 therearound. In fig. 32, the nanostructure 2021 is disposed at the center of the superstructure unit 203 of a regular quadrangle.

According to the embodiment of the present application, a in fig. 33 to d in fig. 33 respectively show that the shape of the nanostructure 2021 includes a square column, a cylinder, a hollow square column, and a hollow cylinder, and the nanostructure 2021 is not surrounded by the filler 2022. In fig. 33 a to fig. 33 d, the nanostructure 2021 is disposed at the center of the regular hexagonal superstructure unit 203. Alternatively, e in fig. 33 to h in fig. 33 respectively show that the nanostructure 2021 is a negative nanostructure, such as a square hole pillar, a circular hole pillar, a square ring pillar, and a circular ring pillar. In fig. 33 e to fig. 33 h, the nanostructure 2021 is a negative structure disposed at the center of the superstructure unit 203 of a regular hexagon.

In an alternative embodiment, as shown in fig. 36, the superlens provided in the example of the present application further includes an anti-reflection film 204. The antireflection film 204 is disposed on a side of the substrate layer 201 away from the at least one nanostructure layer 202; alternatively, the antireflection film 204 is disposed on a side of the at least one nanostructure layer 202 adjacent to air. The antireflection film 204 functions to perform antireflection and antireflection functions on incident radiation.

According to an embodiment of the present application, the base layer 201 is made of a material having an extinction coefficient of less than 0.01 with respect to the operating band. For example, the material of the substrate layer 201 includes fused quartz, quartz glass, crown glass, flint glass, sapphire, crystalline silicon, amorphous silicon, and hydrogenated amorphous silicon. For another example, when the operating wavelength band of the superlens is the visible wavelength band, the material of the substrate layer 201 includes fused silica, quartz glass, crown glass, flint glass, sapphire, and alkali glass. In some embodiments of the present application, the material of the nanostructures 2021 is the same as the material of the substrate layer 201. In some embodiments of the present application, the material of the nano-structure 2021 is different from the material of the substrate layer 201. Optionally, the filler 2022 is the same material as the base layer 201. Optionally, the filler 2022 is of a different material than the base layer 201.

It is to be understood that in some alternative embodiments of the present application, the filler 2022 is the same material as the nanostructures 2021. In some alternative embodiments of the present application, the filler 2022 and the nano-structure 2021 are made of different materials. Illustratively, the filler 2022 is a high transmittance material in the operating band, and has an extinction coefficient of less than 0.01. Illustratively, the material of the filler 2022 includes fused quartz, quartz glass, crown glass, flint glass, sapphire, crystalline silicon, amorphous silicon, and hydrogenated amorphous silicon.

Optionally, the superlens provided by the embodiment of the present application has an equivalent refractive index range smaller than 2. The equivalent refractive index range is the maximum refractive index of the superlens minus its minimum refractive index. According to the implementation manner of the present application, the phase of the superlens provided by the embodiment of the present application also satisfies formula (7):

wherein r is the distance from the center of the superlens to the center of any nanostructure; λ is the operating wavelength of the superlens,

for any phase associated with the wavelength of operation, (x, y) are the coordinates on the superlens (which in some cases may be understood as the coordinates of the surface of the substrate layer 201), f _ML Is the focal length of the second lens 20, a _i And b _i Are real number coefficients. The phase of the superlens may be expressed in higher order polynomials, including odd and even polynomials. In order not to destroy the rotational symmetry of the phase of the superlens, the phase corresponding to the even-order polynomial can be optimized, which greatly reduces the degree of freedom of the design of the superlens. In the formulas (7-1) to (7-8), compared with the other formulas, the formulas (7-4) to (7-6) can optimize the phase satisfying the odd polynomial without destroying the rotational symmetry of the phase of the superlens, thereby greatly improving the optimization degree of freedom of the superlens.

Optionally, the matching of the actual phase of the superlens provided in the embodiment of the present application with the ideal phase, that is, the degree of matching of the broadband phase of the superlens is given by equation (8):

λ in the formula (8) _max And λ _min Respectively, the upper and lower limits of the operating band of the superlens, e.g. λ _max ＝700nm，λ _min ＝400nm。

And

the theoretical target phase and the actual in-database phase, respectively.

Further, the aspheric surfaces in the aspheric refractive lens of the optical system provided by the embodiments of the present application satisfy:

in formula (9), z represents a surface vector parallel to the z axis, the z axis is the optical axis of the optical system, c is the curvature of the central point of the aspheric surface, k is a conic constant, and a to J correspond to high-order coefficients, respectively.

In an alternative embodiment, as shown in fig. 1 to 24, the optical system provided in the embodiment of the present application further includes a diaphragm 80. The stop 80 may be disposed on the object side or image side of any aspheric refractive or superlens in the optical system. The stop 80 helps to compress the radius of the lens downstream in the path of the incident light, thereby facilitating miniaturization of the optical system.

According to some further alternative embodiments of the present application, as shown in fig. 1 to 24, the optical system provided in the embodiment of the present application further includes an infrared filter 90. The infrared filter 90 is disposed between the seventh lens 70 and an image plane of the optical system provided in the embodiment of the present application. When the operating band of the optical system is the visible band, the infrared filter 90 is beneficial to filtering the radiation of the infrared band, so as to improve the imaging quality of the optical system, and simultaneously, the damage caused by burning of the photosensitive element matched with the optical system can be avoided.

Example 1

Illustratively, the embodiment of the present application provides a superlens. The superlens includes a substrate layer 201 and two nanostructure layers 202 disposed on the substrate layer 201. The first nanostructure layer and the second nanostructure layer are sequentially arranged in the two nanostructure layers 202 along a direction away from the substrate layer 201. Specific parameters of the superlens are shown in table 1. Fig. 37 shows a phase diagram of the superlens provided in example 1, with the abscissa of fig. 37 being the wavelength of the incident radiation and the ordinate being the radius of the nanostructure 2021. Fig. 38 shows a transmission diagram of the superlens provided in example 1, with the abscissa of fig. 38 being the wavelength of the incident radiation and the ordinate being the radius of the nanostructure 2021.

In embodiment 1, the phase of the wide spectrum of any superstructure unit 203 in the superlens satisfies the following conditions corresponding to the wavelength:

wherein r is the radial coordinate of the superlens; r is a radical of hydrogen ₀ The distance from any point on the superlens to the center of the superlens; λ is the operating wavelength of the superlens.

TABLE 1

Example 2

In yet another exemplary embodiment, the present application provides a superlens. The superlens includes a base layer 201 and two nanostructure layers 202 disposed on the base layer 201. The first nanostructure layer and the second nanostructure layer are sequentially arranged in the two nanostructure layers 202 along a direction away from the substrate layer 201. Specific parameters of the superlens are shown in table 2. Fig. 39 shows a phase diagram of the superlens provided in example 2, the abscissa of fig. 39 being the wavelength of the incident radiation and the ordinate being the radius of the nanostructure 2021. Fig. 40 shows a transmission diagram of the superlens provided in example 2, with the abscissa of fig. 40 being the wavelength of the incident radiation and the ordinate being the radius of the nanostructure 2021.

In embodiment 2, the phase of the wide spectrum of any superstructure unit 203 in the superlens satisfies the following conditions corresponding to the wavelength:

wherein r is the radial coordinate of the superlens; r is ₀ The distance from any point on the super lens to the center of the super lens; λ is the operating wavelength of the superlens.

TABLE 2

In a second aspect, an embodiment of the present application further provides a method for processing a superlens, which is suitable for the second lens 20 provided in any embodiment of the present application. As shown in fig. 41 to 43, the method includes at least steps S1 to S5.

In step S1, a layer of structural layer material 202a is disposed on the base layer 201.

In step S2, a photoresist 205 is coated on the structural layer material 202a, and the reference structure 206 is exposed.

In step S3, periodically arranged nanostructures 2021 are etched on the structural layer material 202a according to the reference structure 206 to form the nanostructure layer 202.

In step S4, fillers 2022 are disposed between the nanostructures 2021.

In step S5, the surface of the filler 2022 is trimmed to make the surface of the filler 2022 coincide with the surface of the nanostructure 2021.

Optionally, as shown in fig. 42, the method provided in the embodiment of the present application further includes:

step S6, repeating steps S1 to S5 until the setting of all nanostructure layers is completed.

Example 3

Exemplary, embodiment 3 provides an optical system, the structure of which is shown in fig. 1. The optical system comprises a diaphragm 80, a first lens 10, a second lens 20, a third lens 30, a fourth lens 40, a fifth lens 50, a sixth lens 60, a seventh lens 70 and an infrared filter 90 which are arranged in sequence from an object side to an image side. The specific parameters of the optical system are shown in Table 3-1. The parameters of curvature, thickness, refractive index, etc. of each surface of each lens in the optical system are shown in table 3-2. The aspherical surface coefficients of the respective surfaces of the respective lenses in the optical system are shown in tables 3-3-1 and 3-3-2, and the aspherical surface coefficients are shown in formula (9).

Fig. 44 shows phase modulation diagrams of the superlens at 486.13nm, 587.56nm and 656.27nm in the optical system provided by embodiment 3. As can be seen from FIG. 44, the phase coverage of the superlens at different wavelengths is 0-2 π. Fig. 45 shows an astigmatism diagram of the optical system. As can be seen from fig. 45, the astigmatism of this optical system does not exceed 0.5 mm. Fig. 46 shows a distortion diagram of the optical system. As can be seen from fig. 46, the distortion of the optical system in the 0 to 1 field of view is not more than 5%. Fig. 47 shows the degree of broadband matching of the superlens in the optical system provided in embodiment 3. As can be seen from fig. 47, the actual phase of the superlens in example 3 matches the theoretical phase by more than 90%. As can be seen from the above, the optical system provided in example 3 has a good imaging effect and excellent astigmatism and distortion control.

TABLE 3-1

Item of parameter	Numerical value
		Working band (WL)	VIS(400-700nm)
Equivalent Focal Length (EFL)	4.1mm
		Viewing angle (2 omega)	74°
F number	1.6
		Image height (ImgH)	3.09mm
Total System Length (TTL)	5.4mm

TABLE 3-2

TABLE 3-3-1

TABLE 3-3-2

Example 4

Exemplary, embodiment 4 provides an optical system whose structure is shown in fig. 2. The optical system comprises a diaphragm 80, a first lens 10, a second lens 20, a third lens 30, a fourth lens 40, a fifth lens 50, a sixth lens 60, a seventh lens 70 and an infrared filter 90 which are arranged in sequence from an object side to an image side. The specific parameters of the optical system are shown in Table 4-1. The parameters of curvature, thickness, refractive index, etc. of each surface of each lens in the optical system are shown in table 4-2. The aspherical surface coefficients of the respective surfaces of the respective lenses in the optical system are shown in tables 4-3-1 and 4-3-2, and the aspherical surface coefficients are shown in formula (9).

Fig. 48 shows a schematic diagram of phase modulation at 486.13nm, 587.56nm and 656.27nm of a superlens in an optical system provided by embodiment 4. As can be seen from FIG. 48, the phase coverage of the superlens at different wavelengths is 0-2 π. Fig. 49 shows an astigmatism diagram of the optical system. As can be seen from fig. 49, the astigmatism of this optical system does not exceed 0.5 mm. Fig. 50 shows a distortion diagram of the optical system. As can be seen from fig. 50, the distortion of the optical system within the 0 to 1 field of view is not more than 5%. Fig. 51 shows the degree of broadband matching of the superlens in the optical system provided in embodiment 4. As can be seen from fig. 51, the degree of matching between the actual phase and the theoretical phase of the superlens in embodiment 4 is greater than 90%. As can be seen from the above, the optical system provided in example 4 has a good imaging effect and excellent astigmatism and distortion control.

TABLE 4-1

Item of parameter	Numerical value
		Working band (WL)	VIS(400-700nm)
Equivalent Focal Length (EFL)	4.1mm
		Viewing angle (2 omega)	74°
F number	1.8
		Image height (ImgH)	3.0896mm
Total System Length (TTL)	5.2mm

TABLE 4-2

TABLE 4-3-1

TABLE 4-3-2

Example 5

Exemplary, embodiment 5 provides an optical system whose structure is shown in fig. 3. The optical system comprises a diaphragm 80, a first lens 10, a second lens 20, a third lens 30, a fourth lens 40, a fifth lens 50, a sixth lens 60, a seventh lens 70 and an infrared filter 90 which are sequentially arranged from an object side to an image side. The specific parameters of the optical system are shown in Table 5-1. The parameters of curvature, thickness, refractive index, etc. of each surface of each lens in the optical system are shown in Table 5-2. The aspherical surface coefficients of the respective surfaces of the respective lenses in the optical system are shown in tables 5-3-1 and 5-3-2, and the aspherical surface coefficients are shown in formula (9).

Fig. 52 shows a schematic diagram of phase modulation of the superlens at 486.13nm, 587.56nm and 656.27nm in the optical system provided by embodiment 5. As can be seen from FIG. 52, the phase coverage of the superlens is 0-2 π at different wavelengths. Fig. 53 shows an astigmatism diagram of the optical system. As can be seen from fig. 53, the astigmatism of the optical system does not exceed 0.5 mm. Fig. 54 shows a distortion diagram of the optical system. As can be seen from fig. 54, the distortion of the optical system in the 0 to 1 field of view is not more than 5%. Fig. 55 shows the degree of broadband matching of the superlens in the optical system provided in example 5. As can be seen from fig. 55, the degree of matching between the actual phase and the theoretical phase of the superlens in example 5 is greater than 90%. As can be seen from the above, the optical system provided in example 5 has a good imaging effect and excellent astigmatism and distortion control.

TABLE 5-1

Item of parameter	Numerical value
		Operating band (WL)	VIS(400-700nm)
Equivalent Focal Length (EFL)	4.1mm
		Viewing angle (2 omega)	74°
F number	1.8
		Image height (ImgH)	3.0896mm
Total System Length (TTL)	5.2mm

TABLE 5-2

TABLE 5-3-1

TABLE 5-3-2

Example 6

Exemplary, embodiment 6 provides an optical system whose structure is shown in fig. 4. The optical system comprises a diaphragm 80, a first lens 10, a second lens 20, a third lens 30, a fourth lens 40, a fifth lens 50, a sixth lens 60, a seventh lens 70 and an infrared filter 90 which are arranged in sequence from an object side to an image side. The specific parameters of the optical system are shown in Table 6-1. The parameters of curvature, thickness, refractive index, etc. of each surface of each lens in the optical system are shown in Table 6-2. The aspherical surface coefficients of the respective surfaces of the respective lenses in the optical system are shown in tables 6-3-1 and 6-3-2, and the aspherical surface coefficients are shown in formula (9).

Fig. 56 shows phase modulation diagrams of the superlens at 486.13nm, 587.56nm and 656.27nm in the optical system provided by embodiment 6. As can be seen from FIG. 56, the phase coverage of the superlens at different wavelengths is 0-2 π. Fig. 57 shows an astigmatism diagram of the optical system. As can be seen from fig. 57, the astigmatism of this optical system does not exceed 0.5 mm. Fig. 58 shows a distortion diagram of the optical system. As can be seen from fig. 58, the distortion of the optical system in the 0 to 1 field of view is not more than 5%. Fig. 59 shows the degree of broadband matching of the superlens in the optical system provided in embodiment 6. As can be seen from fig. 59, the degree of matching between the actual phase and the theoretical phase of the superlens in example 6 is greater than 90%. As can be seen from the above, the optical system provided in example 6 has a good imaging effect and excellent astigmatism and distortion control.

TABLE 6-1

TABLE 6-2

TABLE 6-3-1

TABLE 6-3-2

Example 7

Exemplary, embodiment 7 provides an optical system whose structure is shown in fig. 5. The optical system comprises a diaphragm 80, a first lens 10, a second lens 20, a third lens 30, a fourth lens 40, a fifth lens 50, a sixth lens 60, a seventh lens 70 and an infrared filter 90 which are arranged in sequence from an object side to an image side. The specific parameters of the optical system are shown in Table 7-1. The parameters of curvature, thickness, refractive index, etc. of each surface of each lens in the optical system are shown in Table 7-2. The aspherical surface coefficients of the respective surfaces of the respective lenses in the optical system are shown in tables 7-3-1 and 7-3-2, and the aspherical surface coefficients are shown in formula (9).

Fig. 60 shows phase modulation diagrams of the superlens at 486.13nm, 587.56nm and 656.27nm in the optical system provided by embodiment 7. As can be seen from FIG. 60, the phase coverage of the superlens at different wavelengths is 0-2 π. Fig. 61 shows an astigmatism diagram of the optical system. As can be seen from fig. 61, the astigmatism of this optical system does not exceed 0.5 mm. Fig. 62 shows a distortion diagram of the optical system. As can be seen from fig. 62, the distortion of the optical system in the 0 to 1 field of view is not more than 5%. Fig. 63 shows the degree of broadband matching of the superlens in the optical system provided in example 7. As can be seen from fig. 63, the degree of matching between the actual phase and the theoretical phase of the superlens in example 7 is greater than 90%. As can be seen from the above, the optical system provided in example 7 has a good imaging effect and excellent astigmatism and distortion control.

TABLE 7-1

TABLE 7-2

TABLE 7-3-1

TABLE 7-3-2

Example 8

Exemplary, embodiment 8 provides an optical system whose structure is shown in fig. 6. The optical system comprises a diaphragm 80, a first lens 10, a second lens 20, a third lens 30, a fourth lens 40, a fifth lens 50, a sixth lens 60, a seventh lens 70 and an infrared filter 90 which are arranged in sequence from an object side to an image side. The specific parameters of the optical system are shown in Table 8-1. The parameters of curvature, thickness, refractive index, etc. of each surface of each lens in the optical system are shown in Table 8-2. The aspherical surface coefficients of the respective surfaces of the respective lenses in the optical system are shown in tables 8-3-1 and 8-3-2, and the aspherical surface coefficients are shown in formula (9).

Fig. 64 shows phase modulation diagrams of the superlens at 486.13nm, 587.56nm and 656.27nm in the optical system provided by embodiment 8. From FIG. 64, it can be seen that the phase coverage of the superlens at different wavelengths is 0-2 π. Fig. 65 shows an astigmatism diagram of the optical system. As can be seen from fig. 65, the astigmatism of the optical system does not exceed 0.5 mm. Fig. 66 shows a distortion diagram of the optical system. As can be seen from fig. 66, the distortion of the optical system in the 0 to 1 field of view is not more than 5%. Fig. 67 shows the degree of broadband matching of the superlens in the optical system provided in embodiment 8. As can be seen from fig. 67, the degree of matching between the actual phase and the theoretical phase of the superlens in example 8 is greater than 90%. As can be seen from the above, the optical system provided in example 8 has a good imaging effect and excellent astigmatism and distortion control.

TABLE 8-1

TABLE 8-2

TABLE 8-3-1

TABLE 8-3-2

Example 9

Exemplary embodiment 9 provides an optical system whose structure is shown in fig. 7. The optical system comprises a diaphragm 80, a first lens 10, a second lens 20, a third lens 30, a fourth lens 40, a fifth lens 50, a sixth lens 60, a seventh lens 70 and an infrared filter 90 which are arranged in sequence from an object side to an image side. The specific parameters of the optical system are shown in Table 9-1. The parameters of curvature, thickness, refractive index, etc. of each surface of each lens in the optical system are shown in Table 9-2. The aspherical surface coefficients of the respective surfaces of the respective lenses in the optical system are shown in tables 9-3-1 and 9-3-2, and the aspherical surface coefficients are shown in formula (9).

Fig. 68 shows a schematic diagram of phase modulation at 486.13nm, 587.56nm and 656.27nm of a superlens in an optical system provided by embodiment 9. From FIG. 68, it can be seen that the phase coverage of the superlens at different wavelengths is 0-2 π. Fig. 69 shows an astigmatism diagram of the optical system. As can be seen from fig. 69, the astigmatism of this optical system does not exceed 0.5 mm. Fig. 70 shows a distortion diagram of the optical system. As can be seen from fig. 70, the distortion of the optical system within the 0 to 1 field of view is not more than 5%. Fig. 71 shows the degree of broadband matching of the superlens in the optical system provided in example 9. As can be seen from fig. 71, the degree of matching between the actual phase and the theoretical phase of the superlens in example 9 is greater than 90%. As can be seen from the above, the optical system provided in example 9 has a good imaging effect and excellent astigmatism and distortion control.

TABLE 9-1

TABLE 9-2

TABLE 9-3-1

TABLE 9-3-2

Example 10

Exemplary embodiment 10 provides an optical system whose structure is shown in fig. 8. The optical system comprises a diaphragm 80, a first lens 10, a second lens 20, a third lens 30, a fourth lens 40, a fifth lens 50, a sixth lens 60, a seventh lens 70 and an infrared filter 90 which are arranged in sequence from an object side to an image side. The specific parameters of the optical system are shown in Table 10-1. For the curvature, thickness, refractive index, etc. of each surface of each lens in the optical system, please refer to table 10-2. The aspherical surface coefficients of the respective surfaces of the respective lenses in the optical system are shown in tables 10-3-1 and 10-3-2, and the aspherical surface coefficients are shown in formula (9).

Fig. 72 shows a schematic diagram of phase modulation at 486.13nm, 587.56nm and 656.27nm of a superlens in an optical system provided by embodiment 3. As can be seen from FIG. 72, the phase coverage of the superlens at different wavelengths is 0-2 π. Fig. 73 shows an astigmatism diagram of the optical system. As can be seen from fig. 73, the astigmatism of this optical system does not exceed 0.5 mm. Fig. 74 shows a distortion diagram of the optical system. As can be seen from fig. 74, the distortion of the optical system within the 0 to 1 field of view is not more than 5%. FIG. 75 shows the degree of broadband matching of a superlens in an optical system provided in example 8. As can be seen from fig. 75, the degree of matching between the actual phase and the theoretical phase of the superlens in example 8 is greater than 90%. As can be seen from the above, the optical system provided in example 8 has a good imaging effect and excellent astigmatism and distortion control.

TABLE 10-1

Item of parameter	Numerical value
		Working band (WL)	VIS(400-700nm)
Equivalent Focal Length (EFL)	4.1mm
		Viewing angle (2 omega)	74°
F number	1.8
		Image height (ImgH)	3.0896mm
Total System Length (TTL)	5.4mm

TABLE 10-2

TABLE 10-3-1

TABLE 10-3-2

Example 11

Exemplary, embodiment 11 provides an optical system, the structure of which is shown in fig. 9. The optical system comprises a diaphragm 80, a first lens 10, a second lens 20, a third lens 30, a fourth lens 40, a fifth lens 50, a sixth lens 60, a seventh lens 70 and an infrared filter 90 which are arranged in sequence from an object side to an image side. The specific parameters of the optical system are shown in Table 11-1. The parameters of curvature, thickness, refractive index, etc. of each surface of each lens in the optical system are shown in Table 11-2. The aspherical surface coefficients of the respective surfaces of the respective lenses in the optical system are shown in tables 11-3-1 and 11-3-2, and the aspherical surface coefficients are shown in formula (9).

Fig. 76 shows phase modulation diagrams of the superlens at 486.13nm, 587.56nm and 656.27nm in the optical system provided by embodiment 11. As can be seen from FIG. 76, the phase coverage of the superlens at different wavelengths is 0-2 π. Fig. 77 shows an astigmatism diagram of the optical system. As can be seen from fig. 77, the astigmatism of this optical system does not exceed 0.5 mm. Fig. 78 shows a distortion diagram of the optical system. As can be seen from fig. 78, the distortion of the optical system within the 0 to 1 field of view is not more than 5%. FIG. 79 shows the degree of broadband matching of the superlens in the optical system provided in example 11. As can be seen from fig. 79, the degree of matching between the actual phase and the theoretical phase of the superlens in example 11 is greater than 90%. As can be seen from the above, the optical system provided in example 11 has a good imaging effect and excellent astigmatism and distortion control.

TABLE 11-1

TABLE 11-2

TABLE 11-3-1

TABLE 10-3-2

Example 12

Exemplary, embodiment 12 provides an optical system whose structure is shown in fig. 10. The optical system comprises a diaphragm 80, a first lens 10, a second lens 20, a third lens 30, a fourth lens 40, a fifth lens 50, a sixth lens 60, a seventh lens 70 and an infrared filter 90 which are sequentially arranged from an object side to an image side. The specific parameters of the optical system are shown in Table 12-1. The parameters of curvature, thickness, refractive index, etc. of each surface of each lens in the optical system are shown in Table 12-2. The aspherical surface coefficients of the respective surfaces of the respective lenses in the optical system are shown in tables 12-3-1 and 12-3-2, and the aspherical surface coefficients are shown in formula (9).

FIG. 80 shows the phase modulation diagrams of the superlens at 486.13nm, 587.56nm and 656.27nm in the optical system provided by embodiment 3. As can be seen from FIG. 80, the phase coverage of the superlens at different wavelengths is 0-2 π. Fig. 81 shows an astigmatism diagram of the optical system. As can be seen from fig. 81, the astigmatism of this optical system does not exceed 0.5 mm. Fig. 82 shows a distortion diagram of the optical system. As can be seen from fig. 82, the distortion of the optical system in the 0 to 1 field of view is not more than 5%. Fig. 83 shows the degree of broadband matching of the superlens in the optical system provided in example 12. As can be seen from fig. 83, the degree of matching between the actual phase and the theoretical phase of the superlens in example 12 is greater than 90%. As can be seen from the above, the optical system provided in example 12 has a good imaging effect and is excellent in astigmatism and distortion control.

TABLE 12-1

Parameter item	Numerical value
		Working band (WL)	VIS(400-700nm)
Equivalent Focal Length (EFL)	4.1mm
		Viewing angle (2 omega)	74°
F number	1.8
		Image height (ImgH)	3.0896mm
Total System Length (TTL)	5.4mm

TABLE 12-2

TABLE 12-3-1

TABLE 12-3-2

Example 13

Exemplary embodiment 13 provides an optical system whose structure is shown in fig. 11. The optical system comprises a diaphragm 80, a first lens 10, a second lens 20, a third lens 30, a fourth lens 40, a fifth lens 50, a sixth lens 60, a seventh lens 70 and an infrared filter 90 which are arranged in sequence from an object side to an image side. The specific parameters of the optical system are shown in Table 13-1. The parameters of curvature, thickness, refractive index, etc. of each surface of each lens in the optical system are shown in Table 13-2. The aspherical surface coefficients of the respective surfaces of the respective lenses in the optical system are shown in tables 13-3-1 and 13-3-2, and the aspherical surface coefficients are shown in formula (9).

Fig. 84 shows a schematic diagram of phase modulation at 486.13nm, 587.56nm and 656.27nm of a superlens in an optical system provided by embodiment 3. From FIG. 84, it can be seen that the phase coverage of the superlens at different wavelengths is 0-2 π. Fig. 85 shows an astigmatism diagram of the optical system. As can be seen from fig. 85, the astigmatism of the optical system does not exceed 0.5 mm. Fig. 86 shows a distortion diagram of the optical system. As can be seen from fig. 86, the distortion of the optical system in the 0 to 1 field of view is not more than 5%. Fig. 87 shows the degree of broadband matching of the superlens in the optical system provided in example 13. As can be seen from fig. 87, the degree of matching between the actual phase and the theoretical phase of the superlens in example 13 is greater than 90%. As can be seen from the above, the optical system provided in example 13 has a good imaging effect and is excellent in astigmatism and distortion control.

TABLE 13-1

Parameter item	Numerical value
		Working band (WL)	VIS(400-700nm)
Equivalent Focal Length (EFL)	4.63mm
		Viewing angle (2 omega)	74°
F number	2.0
		Image height (ImgH)	3.4896mm
Total System Length (TTL)	5.3mm

TABLE 13-2

TABLE 13-3-1

TABLE 13-3-2

Example 14

Exemplary embodiment 14 provides an optical system whose structure is shown in fig. 12. The optical system comprises a diaphragm 80, a first lens 10, a second lens 20, a third lens 30, a fourth lens 40, a fifth lens 50, a sixth lens 60, a seventh lens 70 and an infrared filter 90 which are arranged in sequence from an object side to an image side. The specific parameters of the optical system are shown in Table 14-1. The parameters of curvature, thickness, refractive index, etc. of each surface of each lens in the optical system are shown in Table 14-2. The aspherical surface coefficients of the respective surfaces of the respective lenses in the optical system are shown in tables 14-3-1 and 14-3-2, and the aspherical surface coefficients are shown in formula (9).

Fig. 88 shows a schematic diagram of phase modulation at 486.13nm, 587.56nm and 656.27nm of a superlens in an optical system provided by embodiment 12. As can be seen from FIG. 88, the phase coverage of the superlens at different wavelengths is 0-2 π. Fig. 89 shows an astigmatism diagram of the optical system. As can be seen from fig. 89, the astigmatism of this optical system does not exceed 0.5 mm. Fig. 90 shows a distortion diagram of the optical system. As can be seen from fig. 90, the distortion of the optical system within the 0 to 1 field of view is not more than 5%. FIG. 91 shows the degree of broadband matching of the superlens in the optical system provided in example 14. As can be seen from fig. 91, the degree of matching between the actual phase and the theoretical phase of the superlens in example 14 is greater than 90%. As can be seen from the above, the optical system provided in example 14 has a good imaging effect and excellent astigmatism and distortion control.

TABLE 14-1

Item of parameter	Numerical value
		Working band (WL)	VIS(400-700nm)
Equivalent Focal Length (EFL)	4.63mm
		Viewing angle (2 omega)	74°
F number	2.0
		Image height (ImgH)	3.4896mm
Total System Length (TTL)	5.3mm

TABLE 14-2

TABLE 14-3-1

TABLE 14-3-2

Example 15

Exemplary, embodiment 15 provides an optical system whose structure is shown in fig. 13. The optical system comprises a diaphragm 80, a first lens 10, a second lens 20, a third lens 30, a fourth lens 40, a fifth lens 50, a sixth lens 60, a seventh lens 70 and an infrared filter 90 which are arranged in sequence from an object side to an image side. The specific parameters of the optical system are shown in Table 15-1. The parameters of curvature, thickness, refractive index, etc. of each surface of each lens in the optical system are shown in Table 15-2. The aspherical surface coefficients of the respective surfaces of the respective lenses in the optical system are shown in tables 15-3-1 and 15-3-2, and the aspherical surface coefficients are shown in formula (9).

Fig. 92 shows a schematic diagram of phase modulation at 486.13nm, 587.56nm and 656.27nm of a superlens in an optical system provided by embodiment 15. From FIG. 92, it can be seen that the phase coverage of the superlens at different wavelengths is 0-2 π. Fig. 93 shows an astigmatism diagram of the optical system. As can be seen from fig. 93, the astigmatism of the optical system does not exceed 0.5 mm. Fig. 94 shows a distortion diagram of the optical system. As can be seen from fig. 94, the distortion of the optical system in the 0 to 1 field of view is not more than 5%. Fig. 95 shows the degree of broadband matching of the superlens in the optical system provided in example 15. As can be seen from fig. 95, the degree of matching between the actual phase and the theoretical phase of the superlens in example 15 is greater than 90%. As can be seen from the above, the optical system provided in example 15 has a good imaging effect and is excellent in astigmatism and distortion control.

TABLE 15-1

Item of parameter	Numerical value
		Working band (WL)	VIS(400-700nm)
Equivalent Focal Length (EFL)	4.63mm
		Viewing angle (2 omega)	74°
F number	2.0
		High (ImgH)	3.4896mm
Total System Length (TTL)	5.3mm

TABLE 15-2

TABLE 15-3-1

TABLE 15-3-2

Example 16

Exemplary embodiment 16 provides an optical system whose structure is shown in fig. 14. The optical system comprises a diaphragm 80, a first lens 10, a second lens 20, a third lens 30, a fourth lens 40, a fifth lens 50, a sixth lens 60, a seventh lens 70 and an infrared filter 90 which are arranged in sequence from an object side to an image side. The specific parameters of the optical system are shown in Table 16-1. The parameters of curvature, thickness, refractive index, etc. of each surface of each lens in the optical system are shown in Table 16-2. The aspherical surface coefficients of the respective surfaces of the respective lenses in the optical system are shown in tables 16-3-1 and 16-3-2, and the aspherical surface coefficients are shown in formula (9).

FIG. 96 is a diagram showing phase modulations at 486.13nm, 587.56nm and 656.27nm of a superlens in an optical system provided by embodiment 16. As can be seen from FIG. 96, the phase coverage of the superlens at different wavelengths is 0-2 π. Fig. 97 shows an astigmatism diagram of the optical system. As can be seen from fig. 97, the astigmatism of this optical system does not exceed 0.5 mm. Fig. 98 shows a distortion diagram of the optical system. As can be seen from fig. 98, the distortion of the optical system in the 0 to 1 field of view is not more than 5%. FIG. 99 shows the degree of broadband matching of a superlens in an optical system provided by example 16. As can be seen from fig. 99, the degree of matching between the actual phase and the theoretical phase of the superlens in example 16 is greater than 90%. As can be seen from the above, the optical system provided in example 16 has a good imaging effect and excellent astigmatism and distortion control.

TABLE 16-1

TABLE 16-2

TABLE 16-3-1

TABLE 16-3-2

Example 17

Exemplary, embodiment 17 provides an optical system whose structure is shown in fig. 15. The optical system comprises a diaphragm 80, a first lens 10, a second lens 20, a third lens 30, a fourth lens 40, a fifth lens 50, a sixth lens 60, a seventh lens 70 and an infrared filter 90 which are arranged in sequence from an object side to an image side. The specific parameters of the optical system are shown in Table 17-1. The parameters of curvature, thickness, refractive index, etc. of each surface of each lens in the optical system are shown in Table 17-2. The aspherical surface coefficients of the respective surfaces of the respective lenses in the optical system are shown in tables 3-3-1 and 17-3-2, and the aspherical surface coefficients are shown in formula (9).

Fig. 100 shows a schematic diagram of phase modulation at 486.13nm, 587.56nm and 656.27nm of a superlens in an optical system provided by embodiment 17. As can be seen from the graph 100, the phase coverage of the superlens at different wavelengths is 0-2 π. Fig. 101 shows an astigmatism diagram of the optical system. As can be seen from fig. 101, the astigmatism of this optical system does not exceed 0.5 mm. Fig. 102 shows a distortion diagram of the optical system. As can be seen from fig. 102, the distortion of the optical system within the 0 to 1 field of view is not more than 5%. FIG. 103 shows the degree of broadband matching of a superlens in an optical system provided in example 17. As can be seen from fig. 103, the degree of matching between the actual phase and the theoretical phase of the superlens in example 17 is greater than 90%. As can be seen from the above, the optical system provided in example 17 is excellent in imaging effect and excellent in astigmatism and distortion control.

TABLE 17-1

TABLE 17-2

TABLE 17-3-1

TABLE 17-3-2

Example 18

Exemplary, embodiment 18 provides an optical system whose structure is shown in fig. 16. The optical system comprises a diaphragm 80, a first lens 10, a second lens 20, a third lens 30, a fourth lens 40, a fifth lens 50, a sixth lens 60, a seventh lens 70 and an infrared filter 90 which are sequentially arranged from an object side to an image side. The specific parameters of the optical system are shown in Table 18-1. The parameters of curvature, thickness, refractive index, etc. of each surface of each lens in the optical system are shown in Table 18-2. The aspherical surface coefficients of the respective surfaces of the respective lenses in the optical system are shown in tables 18-3-1 and 18-3-2, and the aspherical surface coefficients are shown in formula (9).

Fig. 104 shows phase modulation diagrams of the superlens at 486.13nm, 587.56nm and 656.27nm in the optical system provided by embodiment 18. From FIG. 104, it can be seen that the phase coverage of the superlens at different wavelengths is 0-2 π. Fig. 105 shows an astigmatism diagram of the optical system. As can be seen from fig. 105, the astigmatism of the optical system does not exceed 0.5 mm. Fig. 106 shows a distortion diagram of the optical system. As can be seen from fig. 106, the distortion of the optical system within the 0 to 1 field of view is not more than 5%. FIG. 107 shows the degree of broadband matching of a superlens in an optical system provided in example 18. As can be seen from fig. 107, the degree of matching between the actual phase and the theoretical phase of the superlens in example 18 is greater than 90%. As can be seen from the above, the optical system provided in example 18 has a good imaging effect and excellent astigmatism and distortion control.

TABLE 18-1

Item of parameter	Numerical value
		Working band (WL)	VIS(400-700nm)
Equivalent Focal Length (EFL)	4.63mm
		Viewing angle (2 omega)	74°
F number	2.0
		Image height (ImgH)	3.4896mm
Total System Length (TTL)	5.5mm

TABLE 18-2

TABLE 18-3-1

TABLE 18-3-2

Example 19

Exemplary embodiment 19 provides an optical system whose structure is shown in fig. 17. The optical system comprises a diaphragm 80, a first lens 10, a second lens 20, a third lens 30, a fourth lens 40, a fifth lens 50, a sixth lens 60, a seventh lens 70 and an infrared filter 90 which are arranged in sequence from an object side to an image side. The specific parameters of the optical system are shown in Table 19-1. The parameters of curvature, thickness, refractive index, etc. of each surface of each lens in the optical system are shown in Table 19-2. The aspherical surface coefficients of the respective surfaces of the respective lenses in the optical system are shown in tables 19-3-1 and 19-3-2, and the aspherical surface coefficients are shown in formula (9).

Fig. 108 shows phase modulation diagrams of the superlens at 486.13nm, 587.56nm and 656.27nm in the optical system provided by embodiment 19. From FIG. 108, it can be seen that the phase coverage of the superlens at different wavelengths is 0-2 π. Fig. 109 shows an astigmatism diagram of the optical system. As can be seen from fig. 109, the astigmatism of the optical system does not exceed 0.5 mm. Fig. 110 shows a distortion diagram of the optical system. As can be seen from fig. 110, the distortion of the optical system within the 0 to 1 field of view is not more than 5%. Fig. 111 shows the degree of broadband matching of the superlens in the optical system provided in example 19. As can be seen from fig. 111, the degree of matching between the actual phase and the theoretical phase of the superlens in example 19 is greater than 90%. As can be seen from the above, the optical system provided in example 19 is excellent in imaging effect and excellent in astigmatism and distortion control.

TABLE 19-1

TABLE 19-2

TABLE 19-3-1

TABLE 19-3-2

Example 20

Exemplary embodiment 20 provides an optical system whose structure is shown in fig. 18. The optical system comprises a diaphragm 80, a first lens 10, a second lens 20, a third lens 30, a fourth lens 40, a fifth lens 50, a sixth lens 60, a seventh lens 70 and an infrared filter 90 which are arranged in sequence from an object side to an image side. The specific parameters of the optical system are shown in Table 18-1. The parameters of curvature, thickness, refractive index, etc. of each surface of each lens in the optical system are shown in Table 18-2. The aspherical surface coefficients of the respective surfaces of the respective lenses in the optical system are shown in tables 18-3-1 and 18-3-2, and the aspherical surface coefficients are shown in formula (9).

Fig. 112 shows phase modulation diagrams of the superlens at 486.13nm, 587.56nm and 656.27nm in the optical system provided by embodiment 20. From FIG. 112, it can be seen that the phase coverage of the superlens at different wavelengths is 0-2 π. Fig. 113 shows an astigmatism diagram of the optical system. As can be seen from fig. 113, the astigmatism of this optical system is not more than 0.5 mm. Fig. 114 shows a distortion diagram of the optical system. As can be seen from fig. 114, the distortion of the optical system in the 0 to 1 field of view is not more than 5%. FIG. 115 shows the degree of broadband matching of the superlens in the optical system provided in example 20. As can be seen from fig. 115, the degree of matching between the actual phase and the theoretical phase of the superlens in example 20 is greater than 90%. As can be seen from the above, the optical system provided in example 20 has a good imaging effect and excellent astigmatism and distortion control.

TABLE 20-1

Item of parameter	Numerical value
		Working band (WL)	VIS(400-700nm)
Equivalent Focal Length (EFL)	4.63mm
		Angle of view (2 ω))	74°
F number	2.0
		Image height (ImgH)	3.4896mm
Total System Length (TTL)	5.5mm

TABLE 20-2

TABLE 20-3-1

TABLE 20-3-2

Example 21

Exemplary, embodiment 21 provides an optical system whose structure is shown in fig. 19. The optical system comprises a diaphragm 80, a first lens 10, a second lens 20, a third lens 30, a fourth lens 40, a fifth lens 50, a sixth lens 60, a seventh lens 70 and an infrared filter 90 which are arranged in sequence from an object side to an image side. Specific parameters of the optical system are shown in Table 21-1. For the curvature, thickness, refractive index, etc. of each surface of each lens in the optical system, see table 21-2. The aspherical surface coefficients of the respective surfaces of the respective lenses in the optical system are shown in tables 21-3-1 and 21-3-2, and the aspherical surface coefficients are shown in formula (9).

Fig. 116 shows phase modulation diagrams of the superlens at 486.13nm, 587.56nm and 656.27nm in the optical system provided by embodiment 21. As can be seen from FIG. 116, the phase coverage of the superlens at different wavelengths is 0-2 π. Fig. 117 shows an astigmatism diagram of the optical system. As can be seen from fig. 117, the astigmatism of this optical system does not exceed 0.5 mm. Fig. 118 shows a distortion diagram of the optical system. As can be seen from fig. 118, the distortion of the optical system within the 0 to 1 field of view is not more than 5%. Fig. 119 shows the degree of broadband matching of the superlens in the optical system provided in example 21. As can be seen from fig. 119, the degree of matching between the actual phase and the theoretical phase of the superlens in example 21 is greater than 90%. As can be seen from the above, the optical system provided in example 21 has a good imaging effect and excellent astigmatism and distortion control.

TABLE 21-1

TABLE 21-2

TABLE 21-3-1

TABLE 21-3-2

Example 22

Exemplary embodiment 22 provides an optical system whose structure is shown in fig. 20. The optical system comprises a diaphragm 80, a first lens 10, a second lens 20, a third lens 30, a fourth lens 40, a fifth lens 50, a sixth lens 60, a seventh lens 70 and an infrared filter 90 which are arranged in sequence from an object side to an image side. Specific parameters of the optical system are shown in Table 22-1. For the curvature, thickness, refractive index, etc. of each surface of each lens in the optical system, please refer to table 22-2. The aspherical surface coefficients of the respective surfaces of the respective lenses in the optical system are shown in tables 22-3-1 and 22-3-2, and the aspherical surface coefficients are shown in formula (9).

FIG. 120 is a diagram showing phase modulation schemes at 486.13nm, 587.56nm and 656.27nm of a superlens in an optical system provided by embodiment 22. From FIG. 120, it can be seen that the phase coverage of the superlens at different wavelengths is 0-2 π. Fig. 121 shows an astigmatism diagram of the optical system. As can be seen from fig. 121, the astigmatism of this optical system does not exceed 0.5 mm. Fig. 122 shows a distortion diagram of the optical system. As can be seen from fig. 122, the distortion of the optical system within the 0 to 1 field of view is not more than 5%. FIG. 123 shows the degree of broadband matching of a superlens in an optical system provided in example 22. As can be seen from fig. 123, the degree of matching between the actual phase and the theoretical phase of the superlens in example 22 is greater than 90%. As can be seen from the above, the optical system provided in example 22 has a good imaging effect and excellent astigmatism and distortion control.

TABLE 22-1

Item of parameter	Numerical value
		Working band (WL)	VIS(400-700nm)
Equivalent Focal Length (EFL)	4.63mm
		Viewing angle (2 omega)	74°
F number	2.0
		High (ImgH)	3.4896mm
Total System Length (TTL)	5.5mm

TABLE 22-2

TABLE 22-3-1

TABLE 22-3-2

Example 23

Exemplary embodiment 23 provides an optical system whose structure is shown in fig. 21. The optical system comprises a diaphragm 80, a first lens 10, a second lens 20, a third lens 30, a fourth lens 40, a fifth lens 50, a sixth lens 60, a seventh lens 70 and an infrared filter 90 which are arranged in sequence from an object side to an image side. The specific parameters of the optical system are shown in Table 23-1. The parameters of curvature, thickness, refractive index, etc. of each surface of each lens in the optical system are shown in Table 23-2. The aspherical surface coefficients of the respective surfaces of the respective lenses in the optical system are shown in tables 23-3-1 and 23-3-2, and the aspherical surface coefficients are shown in formula (9).

Fig. 124 shows phase modulation diagrams of the superlens at 486.13nm, 587.56nm and 656.27nm in the optical system provided by embodiment 23. As can be seen from FIG. 124, the phase coverage of the superlens is 0-2 π at different wavelengths. Fig. 125 shows an astigmatism diagram of the optical system. As can be seen from fig. 125, the astigmatism of this optical system does not exceed 0.5 mm. Fig. 126 shows a distortion diagram of the optical system. As can be seen from fig. 126, the distortion of the optical system within the 0 to 1 field of view is not more than 5%. FIG. 127 shows the degree of broadband matching of the superlens in the optical system provided in example 23. As can be seen from fig. 127, the degree of matching between the actual phase and the theoretical phase of the superlens in example 23 is greater than 90%. As can be seen from the above, the optical system provided in example 23 is excellent in imaging effect and excellent in astigmatism and distortion control.

TABLE 23-1

Item of parameter	Numerical value
		Working band (WL)	VIS(400-700nm)
Equivalent Focal Length (EFL)	4.63mm
		Viewing angle (2 omega)	74°
F number	2.0
		High (ImgH)	3.4896mm
Total System Length (TTL)	5.7mm

TABLE 23-2

TABLE 23-3-1

TABLE 23-3-2

Example 24

Exemplary embodiment 24 provides an optical system whose structure is shown in fig. 22. The optical system comprises a diaphragm 80, a first lens 10, a second lens 20, a third lens 30, a fourth lens 40, a fifth lens 50, a sixth lens 60, a seventh lens 70 and an infrared filter 90 which are arranged in sequence from an object side to an image side. The specific parameters of the optical system are shown in Table 24-1. The parameters of curvature, thickness, refractive index, etc. of each surface of each lens in the optical system are shown in Table 24-2. The aspherical surface coefficients of the respective surfaces of the respective lenses in the optical system are shown in tables 24-3-1 and 24-3-2, and the aspherical surface coefficients are shown in formula (9).

FIG. 128 is a diagram showing phase modulation schemes at 486.13nm, 587.56nm and 656.27nm of a superlens in the optical system provided by embodiment 24. From FIG. 128, the phase coverage of the superlens at different wavelengths is 0-2 π. Fig. 129 shows an astigmatism diagram of the optical system. As can be seen from fig. 129, the astigmatism of this optical system does not exceed 0.5 mm. Fig. 130 shows a distortion diagram of the optical system. As can be seen from fig. 130, the distortion of the optical system within the 0 to 1 field of view is not more than 5%. FIG. 131 shows the degree of broadband matching of a superlens in an optical system provided in example 24. As can be seen from fig. 131, the degree of matching between the actual phase and the theoretical phase of the superlens in example 24 is greater than 90%. As can be seen from the above, the optical system provided in example 24 has a good imaging effect and excellent astigmatism and distortion control.

TABLE 24-1

Item of parameter	Numerical value
		Working band (WL)	VIS(400-700nm)
Equivalent Focal Length (EFL)	4.63mm
		Viewing angle (2 omega)	74°
F number	2.0
		Image height (ImgH)	3.4896mm
Total System Length (TTL)	5.7mm

TABLE 24-2

TABLE 24-3-1

TABLE 24-3-2

Example 25

Exemplary, embodiment 25 provides an optical system whose structure is shown in fig. 23. The optical system comprises a diaphragm 80, a first lens 10, a second lens 20, a third lens 30, a fourth lens 40, a fifth lens 50, a sixth lens 60, a seventh lens 70 and an infrared filter 90 which are arranged in sequence from an object side to an image side. The specific parameters of the optical system are shown in Table 25-1. The parameters of curvature, thickness, refractive index, etc. of each surface of each lens in the optical system are shown in Table 25-2. The aspherical surface coefficients of the respective surfaces of the respective lenses in the optical system are shown in tables 25-3-1 and 25-3-2, and the aspherical surface coefficients are shown in formula (9).

FIG. 132 is a diagram showing phase modulation schemes at 486.13nm, 587.56nm and 656.27nm of a superlens in the optical system provided by embodiment 25. As can be seen from FIG. 132, the phase coverage of the superlens at different wavelengths is 0-2 π. Fig. 133 shows an astigmatism diagram of the optical system. As can be seen from fig. 133, the astigmatism of this optical system does not exceed 0.5 mm. Fig. 134 shows a distortion diagram of the optical system. As can be seen from fig. 134, the distortion of the optical system in the 0 to 1 field of view is not more than 5%. FIG. 135 shows the degree of broadband matching of the superlens in the optical system provided in example 25. As can be seen from fig. 135, the degree of matching between the actual phase and the theoretical phase of the superlens in example 25 is greater than 90%. As can be seen from the above, the optical system provided in example 25 is excellent in imaging effect and excellent in astigmatism and distortion control.

TABLE 25-1

TABLE 25-2

TABLE 25-3-1

TABLE 25-3-2

Example 26

Exemplary embodiment 26 provides an optical system whose structure is shown in fig. 24. The optical system comprises a diaphragm 80, a first lens 10, a second lens 20, a third lens 30, a fourth lens 40, a fifth lens 50, a sixth lens 60, a seventh lens 70 and an infrared filter 90 which are arranged in sequence from an object side to an image side. The specific parameters of the optical system are shown in Table 26-1. The parameters of curvature, thickness, refractive index, etc. of each surface of each lens in the optical system are shown in Table 26-2. The aspherical surface coefficients of the respective surfaces of the respective lenses in the optical system are shown in tables 26-3-1 and 26-3-2, and the aspherical surface coefficients are shown in formula (9).

Fig. 136 shows phase modulation diagrams of the superlens at 486.13nm, 587.56nm and 656.27nm in the optical system provided by embodiment 3. As can be seen from FIG. 136, the phase coverage of the superlens at different wavelengths is 0-2 π. Fig. 136 shows an astigmatism diagram of the optical system. As can be seen from fig. 137, the astigmatism of this optical system does not exceed 0.5 mm. Fig. 138 shows a distortion diagram of the optical system. As can be seen from fig. 138, the distortion of the optical system within the 0 to 1 field of view is not more than 5%. FIG. 139 shows the degree of broadband matching of a superlens in an optical system provided in example 26. As can be seen from fig. 139, the degree of matching between the actual phase and the theoretical phase of the superlens in example 26 is greater than 90%. As can be seen from the above, the optical system provided in example 26 is excellent in imaging effect and excellent in astigmatism and distortion control.

TABLE 26-1

TABLE 26-2

TABLE 26-3-1

TABLE 26-3-2

It should be noted that the superlens provided by the embodiment of the present application can be processed by a semiconductor process, and has the advantages of light weight, thin thickness, simple structure and process, low cost, high consistency of mass production, and the like.

To sum up, the optical system provided by the embodiment of the present application, through adopting at least one super lens and a plurality of aspheric refractive lenses to form a seven-piece optical system, satisfies that the F number is less than 2 and the total length of the system is less than 6mm, and promotes the miniaturization and light weight of the optical system.

The above description is only a specific implementation of the embodiments of the present application, but the scope of the embodiments of the present application is not limited thereto, and any person skilled in the art can easily conceive of changes or substitutions within the technical scope of the embodiments disclosed in the present application, and all the changes or substitutions should be covered by the scope of the embodiments of the present application. Therefore, the protection scope of the embodiments of the present application shall be subject to the protection scope of the claims.

Claims

1. An optical system is characterized by comprising a first lens (10), a second lens (20), a third lens (30), a fourth lens (40), a fifth lens (50), a sixth lens (60) and a seventh lens (70) which are arranged in sequence from an object side to an image side;

wherein at least one of the first lens (10), the second lens (20), the third lens (30), the fourth lens (40), the fifth lens (50), the sixth lens (60) and the seventh lens (70) is a super lens, and the rest are aspheric refractive lenses;

the optical system further satisfies at least the following condition:

0.05mm≤d _ML ≤2mm；

|f _ML |/f≥45；

2. The optical system according to claim 1, characterized in that said second lens (20) is a superlens, the remaining lenses being aspheric refractive lenses; the first lens (10) has positive focal power, and the object side surface of the first lens (10) is a convex surface; a radius of curvature of an object-side surface of the third lens (30) is positive; the fifth lens (50) has a positive optical power; the curvature radius of the object side surface of the sixth lens (60) is positive.

3. The optical system according to claim 1, characterized in that the first lens (10) further satisfies:

wherein R is _1o Is a radius of curvature of an object-side surface of the first lens (10); f. of ₁ Is the focal length of the first lens (10) at the central wavelength of the working waveband.

4. The optical system of claim 1, wherein the optical system further satisfies:

(V ₁ +V ₄ )/2-V ₃ >20；

wherein, V ₁ Is the abbe number of the first lens (10); v ₃ Is the abbe number of the third lens (30); v ₄ Is the Abbe number of the fourth lens (40).

5. The optical system of claim 1, wherein the optical system further satisfies:

1.5<TTL/ImgH<1.8

wherein TTL is a distance from an object side surface of the first lens (10) to an image plane of the optical system; ImgH is the maximum imaging height of the optical system.

6. The optical system according to claim 1, characterized in that the fourth lens (40) further satisfies:

|R _4o |>R _4i ；

wherein R is _4o Is a radius of curvature of an object-side surface of the fourth lens (40); r is _4i Is a radius of curvature of an image-side surface of the fourth lens (40).

7. The optical system according to claim 1, characterized in that a radius of curvature of an image-side surface of the seventh lens (70) is larger than zero.

8. The optical system according to any one of claims 1 to 5, characterized in that said first lens (10) further satisfies:

0.71≤f ₁ /f≤0.98；

wherein f is ₁ The focal length of the first lens (10) at the central wavelength of the working waveband; f is the focal length of the optical system.

9. The optical system according to claim 1 or 2, characterized in that the superlens comprises a substrate layer (201) and a nanostructured layer (202) arranged on at least one side of the substrate layer (201), and in that the number of layers of the nanostructured layer (202) is greater than or equal to 1;

each of the nanostructure layers (202) comprises periodically arranged nanostructures (2021).

10. The optical system according to claim 9, characterized in that the period of alignment of the nanostructures (2021) in any one of the nanostructure layers (202) is greater than or equal to 0.3 λ c and less than or equal to 2 λ c;

wherein λ c is the central wavelength of the operating band of the second lens (20).

11. The optical system according to claim 9, characterized in that the height of the nanostructures (2021) in any one of the nanostructure layers (202) is greater than or equal to 0.3 λ c and less than or equal to 5 λ c;

12. The optical system according to claim 9, characterized in that the nanostructure layer (202) comprises superstructure units (203) arranged in an array in either layer;

the superstructure unit (203) is a close-packable pattern, the nanostructures (2021) being disposed at vertices and/or a center of the close-packable pattern.

13. The optical system according to claim 9, characterized in that the substrate layer (201) is made of a material having an extinction coefficient to the operating band of less than 0.01.

14. The optical system according to claim 9, characterized in that the material of the nanostructures (2021) has an extinction coefficient of less than 0.01 for the operating band.

15. The optical system according to claim 13, characterized in that the material of the substrate layer (201) comprises fused silica, quartz glass, crown glass, flint glass, sapphire, crystalline silicon, amorphous silicon and hydrogenated amorphous silicon.

16. The optical system according to claim 14, characterized in that the material of the nanostructures (2021) comprises fused silica, quartz glass, crown glass, flint glass, sapphire, crystalline silicon, amorphous silicon and hydrogenated amorphous silicon.

17. The optical system according to claim 9, characterized in that the nanostructure (2021) is of a different material than the substrate layer (201).

18. The optical system according to claim 9, characterized in that the nanostructures (2021) are of the same material as the substrate layer (201).

19. The optical system according to claim 9, characterized in that the shape of the nanostructures (2021) is a polarization insensitive structure.

20. The optical system of claim 19, wherein the polarization insensitive structure comprises a cylinder, a hollow cylinder, a circular hole, a hollow circular hole, a square cylinder, a square hole, a hollow square cylinder, and a hollow square hole.

21. The optical system according to claim 9, characterized in that the second lens (20) further comprises a filler (2022);

the fillers (2022) are filled between the nano structures (2021);

and the extinction coefficient of the material of the filler (2022) to the working waveband is less than 0.01.

22. The optical system according to claim 21, characterized in that the absolute value of the difference between the refractive index of the filler (2022) and the refractive index of the nanostructures (2021) is greater than or equal to 0.5.

23. The optical system of claim 21, wherein the filler comprises air, fused silica, quartz glass, crown glass, flint glass, sapphire, crystalline silicon, amorphous silicon, and hydrogenated amorphous silicon.

24. The optical system according to claim 21, characterized in that the material of the filler (2022) is different from the material of the base layer (201).

25. The optical system according to claim 21, characterized in that the material of the filler (2022) is different from the material of the nanostructures (2021).

26. The optical system of claim 21, wherein the second lens (20) further comprises an antireflection film (204);

the antireflection film (204) is arranged on the side of the substrate layer (201) far away from the nanostructure layer (202), and/or the side of the nanostructure layer (202) far away from the substrate layer (201).

27. The optical system according to claim 12, wherein the wide-spectrum phase of the superstructure unit (203) satisfies:

wherein r is the radial coordinate of the super lens; r is ₀ The distance from any point on the super lens to the center of the super lens; λ is the operating wavelength of the superlens.

28. The optical system according to claim 9, wherein the superlens comprises at least two nanostructure layers (202);

wherein the nanostructures in any two adjacent nanostructure layers (202) are arranged coaxially.

29. The optical system of claim 9, wherein the superlens comprises at least two nanostructure layers (202); wherein the nanostructures in any adjacent nanostructure layer (202) are staggered in a direction parallel to the base of the superlens.

30. The optical system of claim 9, wherein the phase of the superlens further satisfies:

is any phase associated with the working wavelength of the superlens; (x, y) is the superlens mirror coordinates, f ₂ Is the focal length of the superlens; a is _i And b _i Are real coefficients.

31. A method of machining a superlens, adapted for use with the second lens (20) in an optical system according to claim 21, the method comprising:

step S1, arranging a layer of structural layer material (202a) on the base layer (201);

step S2, coating photoresist (205) on the structural layer material (202a), and exposing a reference structure (206);

step S3, etching the periodically arranged nano-structures (2021) on the structure layer material (202a) according to the reference structure (206) to form the nano-structure layer (202);

a step S4 of disposing the filler (2022) between the nanostructures (2021);

step S5, trimming the surface of the filler (2022) to make the surface of the filler (2022) coincide with the surface of the nanostructure (2021).

32. The method of claim 31, further comprising:

33. An image forming apparatus, characterized in that the apparatus comprises

The optical system of any one of claims 1-30; and a photosensitive element disposed on an image plane of the optical system.

34. An electronic device characterized in that the device comprises the imaging apparatus according to claim 33.