CN115453703A

CN115453703A - Achromatic optical lens and method for manufacturing the same

Info

Publication number: CN115453703A
Application number: CN202110642412.5A
Authority: CN
Inventors: 杨萌; 戴付建; 赵烈烽
Original assignee: Zhejiang Sunny Optics Co Ltd
Current assignee: Zhejiang Sunny Optics Co Ltd
Priority date: 2021-06-09
Filing date: 2021-06-09
Publication date: 2022-12-09

Abstract

The present disclosure provides an achromatic optical lens, including: the image sensor includes an image sensor and a plurality of optical elements disposed on a light sensing path of the image sensor. At least one surface of one optical element in the plurality of optical elements is provided with a raised nonmetal micro-nano structure array, wherein the nonmetal micro-nano structure array comprises a plurality of micro-nano structures, and the space volume occupied by the micro-nano structures is changed based on the difference of the positions of the micro-nano structures on the surface, so that the nonmetal micro-nano structure array applies phase modulation with wavelength selectivity to incident light.

Description

Achromatic optical lens and method for manufacturing the same

Technical Field

The present invention relates to the field of optical elements, and more particularly, to an optical lens element for correcting chromatic aberration through an optical micro-nano structure, an achromatic optical lens including the optical lens element, and a method of manufacturing the optical lens element.

Background

Chromatic aberration in an optical lens is a physical phenomenon that different light rays emitted from the same object point cannot be focused on the same position of an image plane after passing through the lens. This phenomenon cannot be eradicated due to the inherent dispersive effects of the lens material and can only be partially mitigated by using a lens material with a lower dispersion.

The physical quantity used to characterize the dispersion of a material is the abbe number. In general, a smaller value of the Abbe number indicates a more significant dispersion phenomenon of the material. However, the abbe number of the resin materials commonly used in the current mobile phone lens is generally below 60, and particularly, the abbe number of the resin materials with high refractive index is generally not higher than 30. This causes the chromatic aberration to be a big aberration difficulty existing in the current mobile phone lens.

In addition, with the increase of the number of lenses in the mobile phone lens and the increase of the application of high-refractive materials, the mobile phone lens with large partial chromatic aberration even causes a purple edge phenomenon, so that the imaging quality and the yield of the lens product are seriously affected. However, since the problem of chromatic aberration relates to the intrinsic optical properties of the material, there has been no solution to this problem in the prior art, and only an optimal solution with a relatively minimum chromatic aberration can be found by optimization of optical parameters.

Disclosure of Invention

The present application provides a solution that may overcome at least or partially overcome at least one of the above-mentioned deficiencies of the prior art.

In one aspect, the present application provides an achromatic optical lens comprising: the image sensor includes an image sensor and a plurality of optical elements disposed on a light sensing path of the image sensor. At least one surface of one optical element in the plurality of optical elements can be provided with a raised non-metal micro-nano structure array. The non-metal micro-nano structure array can comprise a plurality of micro-nano structures, wherein the space volume occupied by the micro-nano structures can be changed based on the position of the micro-nano structures on the surface, so that the non-metal micro-nano structure array can apply phase modulation with wavelength selectivity on incident light.

In some exemplary embodiments, the wavelength selectivity may be characterized by the non-metallic micro-nano structure array having a deflecting effect on one or more wavelengths of the incident light in a wavelength range of 280nm to 2526 nm.

In some exemplary embodiments, the incident light may include first wavelength light and second wavelength light in a wavelength range of 280nm to 2526 nm. The wavelength selectivity can be characterized in that the deflection degree of the non-metal micro-nano structure array to the first wavelength light is larger than the deflection degree of the non-metal micro-nano structure array to the second wavelength light.

In some exemplary embodiments, the phase modulation applied by the array of non-metallic micro-nano structures on the incident light may have field-of-view selectivity.

In some exemplary embodiments, the incident light may include first viewing angle light and second viewing angle light in different viewing angles. The view field selectivity can be characterized in that the deflection degree of the non-metal micro-nano structure array to the first visual angle light is larger than the deflection degree of the non-metal micro-nano structure array to the second visual angle light.

In some exemplary embodiments, the micro-nano structure may have a refractive index greater than a refractive index of each of the plurality of optical elements.

In some exemplary embodiments, a separation distance between adjacent micro-nano structures in the non-metallic micro-nano structure array may be less than 1 μm.

In some exemplary embodiments, the height of the micro-nano structure in a direction perpendicular to the surface may be in a range of 200nm to 2000 nm. In addition, the length of the micro-nano structure in a direction parallel to the surface may be in a range of 100nm to 1000 nm.

In some exemplary embodiments, a ratio of a minimum length to a maximum height of the micro-nano structure may be greater than 1/15.

In some exemplary embodiments, the non-metallic micro-nano structure array may be disposed on an optical element having no optical power.

In some exemplary embodiments, the non-metallic micro-nano structure array may be disposed on a filter sheet having no optical power.

In another aspect, the present application provides a method of manufacturing an achromatic optical lens, the method including: the method comprises the steps of arranging a plurality of optical elements on a photosensitive path of an image sensor, and arranging a raised non-metal micro-nano structure array on at least one surface of one optical element in the plurality of optical elements based on dispersion characteristics of incident light which reaches the image sensor through the plurality of optical elements. The non-metallic micro-nano structure array may include a plurality of micro-nano structures, wherein a volume of a space occupied by the micro-nano structures is changed based on a difference in position of the micro-nano structures on the surface, so that the non-metallic micro-nano structure array applies phase modulation having wavelength selectivity to the incident light.

In some exemplary embodiments, the wavelength selectivity may be characterized in that the non-metallic micro-nano structure array has a deflecting effect on one or more wavelengths of light in a wavelength range of 280nm to 2526nm in the incident light.

In some exemplary embodiments, the incident light may include first and second wavelengths of light in a wavelength range of 280nm to 2526 nm. The wavelength selectivity can be characterized in that the deflection degree of the non-metal micro-nano structure array to the first wavelength light is larger than the deflection degree of the non-metal micro-nano structure array to the second wavelength light.

In some exemplary embodiments, the phase modulation applied by the non-metallic micro-nano structure array on the incident light may have field selectivity.

In some exemplary embodiments, the incident light may include first viewing angle light and second viewing angle light in different viewing angles. The view field selectivity is characterized in that the deflection degree of the non-metal micro-nano structure array to the first visual angle light is larger than the deflection degree of the non-metal micro-nano structure array to the second visual angle light.

In some exemplary embodiments, a separation distance between adjacent micro-nano structures in the non-metal micro-nano structure array may be set to be less than 1 μm.

In some exemplary embodiments, the height of the micro-nano structure in a direction perpendicular to the surface may be set in a range of 200nm to 2000 nm. In addition, the length of the micro-nano structure in a direction parallel to the surface may be set in a range of 100nm to 1000 nm.

In some exemplary embodiments, the array of non-metallic micro-nano structures may be disposed on an optical element having no optical power.

The achromatic optical lens provided by the application is provided with the optical element provided with the nonmetal micro-nano structure array, and can apply phase modulation with wavelength selectivity to incident light, so that chromatic aberration of the incident light with a specific wavelength can be corrected.

Drawings

The above and other advantages of embodiments of the present application will become apparent from the detailed description with reference to the following drawings, which are intended to illustrate exemplary embodiments of the present application and not to limit the same. In the drawings:

fig. 1 shows a schematic structural diagram of an optical lens in the prior art;

fig. 2 and 3 show an on-axis chromatic aberration curve and a magnification chromatic aberration curve, respectively, of the optical lens shown in fig. 1;

FIG. 4 shows a schematic diagram of an array of nanostructures according to an exemplary embodiment of the present application;

FIGS. 5 and 6 are schematic diagrams showing the distribution of incident electric vectors, respectively;

FIG. 7 schematically illustrates a phase modulation versus nanostructure space fraction;

fig. 8 and 9 respectively schematically illustrate the deflection of the nanostructure array for different wavelengths of incident light; and

fig. 10 is a block diagram schematically illustrating a method of manufacturing an achromatic optical lens according to an exemplary embodiment of the present application.

Detailed Description

For a better understanding of the present application, various aspects of the present application will be described in more detail with reference to the accompanying drawings. It should be understood that the detailed description is merely illustrative of exemplary embodiments of the present application and does not limit the scope of the present application in any way. Like reference numerals refer to like elements throughout the specification. The expression "and/or" includes any and all combinations of one or more of the associated listed items.

It should be noted that the expressions first, second, etc. in this specification are used only to distinguish one feature from another feature, and do not indicate any limitation on the features. Thus, a first direction discussed below may also be referred to as a second direction, and vice versa, without departing from the teachings of the present application.

In the drawings, the thickness, size, and shape of each component may have been slightly exaggerated for convenience of explanation. The figures are purely diagrammatic and not drawn to scale. For example, the shapes of the spherical or aspherical surfaces shown in the drawings are shown by way of example. That is, the shape of the spherical surface or the aspherical surface is not limited to the shape of the spherical surface or the aspherical surface shown in the drawings.

Throughout the specification, when an element such as a layer, region or substrate is described as being "on," "connected to" or "coupled to" another element, it can be directly on, "connected to" or "coupled to" the other element or one or more other elements may be present between the element and the other element. In contrast, when an element is referred to as being "directly on," "directly connected to" or "directly coupled to" another element, there may be no other elements intervening between the element and the other element.

Spatially relative terms such as "above 8230; \8230", "above", "below \8230; and" below "may be used herein for convenience of description to describe the relationship of one element to another as shown in the figures. These spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "above" or "upper" relative to other elements would then be oriented "below" or "lower" relative to the other elements. Thus, the wording "above 8230; \8230;" above "encompasses both orientations" above 8230; \8230; "above" and "below 8230;" below "depending on the spatial orientation of the device. The device may also be otherwise oriented (e.g., rotated 90 degrees or at other orientations) and the spatially relative descriptors used in this application should be interpreted accordingly.

It will be further understood that the terms "comprises," "comprising," "has," "having," "includes" and/or "including," when used in this specification, specify the presence of stated features, elements, and/or components, but do not preclude the presence or addition of one or more other features, elements, components, and/or groups thereof. Moreover, when a statement such as "at least one of" appears in the list of listed features, that statement modifies all of the features in the list rather than only individual elements of the list. Furthermore, the use of "may" mean "one or more embodiments of the application" when describing embodiments of the application. Additionally, the word "exemplary" is intended to mean exemplary or illustrative.

As used herein, the terms "approximately," "about," and the like are used as words of table approximation and not as words of table degree, and are intended to account for inherent deviations in measured or calculated values that can be appreciated by one of ordinary skill in the art.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their 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.

In addition, the embodiments and features of the embodiments in the present application may be combined with each other without conflict. In addition, unless explicitly defined or contradicted by context, the specific steps included in the methods described herein are not necessarily limited to the order described, but can be performed in any order or in parallel.

Exemplary embodiments of the present application will be described in detail below with reference to the accompanying drawings.

A related art optical lens may include a plurality of lenses, an optical filter, and an image sensor. The plurality of lenses may each be made of a resin or a glass material. The resin or glass material forming the lens typically has an abbe number of no more than 60.

Fig. 1 shows a schematic structural diagram of an optical lens 10 in the prior art.

As shown in fig. 1, the exemplary optical lens 10 has eight lenses E1 to E8 and one infrared filter E9, but the present application is not limited thereto. Those skilled in the art will appreciate that more and fewer lenses may be included in an optical lens and are not limited to those shown in the figures. Filter E9 is also not limited to being an infrared filter, and in some examples, filter E9 may also be a visible filter, a band pass filter, a cutoff filter, a short wave pass filter, a long wave pass filter, or the like.

The eight lenses E1 to E8 and the infrared filter E9 are arranged in order from the object side to the image side along the optical axis of the optical lens 10. Each of the lenses E1 to E8 and the infrared filter E9 has an object side surface close to the object side and an image side surface close to the image side. Specifically, the first lens E1 has an object side surface S1 and an image side surface S2, the second lens E2 has an object side surface S3 and an image side surface S4, the third lens E3 has an object side surface S5 and an image side surface S6, the fourth lens E4 has an object side surface S7 and an image side surface S8, the fifth lens E5 has an object side surface S9 and an image side surface S10, the sixth lens E6 has an object side surface S11 and an image side surface S12, the seventh lens E7 has an object side surface S13 and an image side surface S14, the eighth lens E8 has an object side surface S15 and an image side surface S16, and the infrared filter E9 has an object side surface S17 and an image side surface S18.

The image sensor is disposed at the position of the imaging surface S19. The image sensor 130 may be a CCD or CMOS sensor for converting the received optical signal into an electrical signal. Light from the object may pass through the surfaces S1-S18 in sequence and eventually be imaged on the imaging plane S19.

The optical lens 10 may further comprise a stop STO for limiting the light beam.

Chromatic aberration occurs on the imaging surface S19 due to chromatic dispersion characteristics inherent to the lens material itself and the influence of the lens structure, and the chromatic aberration varies with the position of the field of view and the wavelength of incident light. Fig. 2 and 3 show an on-axis chromatic aberration curve and a chromatic aberration of magnification curve, respectively, of the optical lens of fig. 1.

As shown in fig. 2 and 3, the chromatic aberration curves of different wavelengths are different from each other. For example, the color difference of some wavelengths may be significantly higher than the color difference of other wavelengths. In addition, for partial fields of view (e.g., intra-field of view), the color difference between different wavelengths is consistent well; while for another part of the field of view (e.g. the out-field of view) the color difference between the different wavelengths may suddenly become larger creating a bottleneck.

It can be observed from the drawings that the chromatic aberration of the exemplary optical lens 10 is relatively the most severe at the 1.0 field of view and for incident light with a wavelength of 656.3nm, and therefore, in particular, a selective correction with a large magnitude is required for the chromatic aberration of the incident light with the 1.0 field of view and for the 656.3nm wavelength, while other wavelengths and fields of view may or may not be corrected with a small magnitude.

It will be understood by those skilled in the art that the chromatic aberration curves vary from lens to lens. Therefore, similar bottlenecks may occur at other fields of view or for incident light of other wavelengths for different lenses, and corresponding corrections may be required to improve the imaging quality. However, such selective correction is difficult to be performed in a manner that does not affect other optical properties of the lens, and in the conventional optical design method, a parameter range with relatively small chromatic aberration can only be found by changing parameters of each lens to compromise, but the effect of correcting chromatic aberration is not ideal.

As known from the fermat principle, light travels along an actual path with an optical path length of a minimum value. The total optical path of light on the actual propagation path between the points A and B is assumed to be

n (r) is the refractive index distribution on the propagation path r, the total optical path is expressed in phase form

k ₀ Is the vacuum wave number. If the interface of two media crossed by light in propagation is introduced into light wave to phi (r) _s ) Is a phase jump of the bit-vector r at the interface _s The total phase corresponding to the actual propagation path of the light wave at two points a and B is:

in the two-dimensional case, it is assumed that the optical wave has a refractive index n from the refractive index _i Is incident on a medium having a refractive index n _t In the medium of (3), it can be obtained that:

the above formula is the generalized law of refraction. Compared with Snell's formula, the above formula introduces

An item. D φ/dx in this term is the phase gradient along the interface direction in the plane defined by the incident and outgoing light.

From equation 2, the classical snell's equation is only a special case of generalized refraction law with zero phase gradient. Outgoing light can be refracted in any direction if a suitable phase gradient is introduced at the interface for the incoming light. That is, the refraction direction of the optical wave can be controlled by controlling the phase gradient at the interface, and the phase gradient interface is equivalent to introducing a non-uniformly distributed phase jump to the incident optical field at the interface.

Based on the above principle, the present application implements achromatization by arranging a non-metal micro-nano structure array on any surface of the lens or the filter (i.e., any surface of the surfaces S1 to S18) other than the imaging surface S19. The nonmetal micro-nano structure array has wavelength selectivity and can be arranged at a field position to be corrected for field selective correction. The non-metallic micro-nano structure array is also referred to as a nano structure array hereinafter.

Particularly, the filter plate has no focal power, so that when the non-metal micro-nano structure array is arranged on the filter plate, a better achromatic effect can be obtained.

Fig. 4 shows a schematic diagram of a nanostructure array according to an exemplary embodiment of the present application.

As shown in fig. 4, the nanostructure array may be disposed on a surface 100. Surface 100 may be any of surfaces S1-S18. The nanostructure array may be arranged at a corresponding location of a desired field of view on the surface 100, as desired. For example, the nanostructure array 120 may be arranged on the surface 100 at the edge of the outer field of view 110, indicated by the outer dashed box. Alternatively, the nanostructure array 121 may be arranged on the surface 100 inside the inner field of view 111, indicated by the inner dashed box.

For the same surface, the nanostructure array may be arranged only at the edge of the outer field of view 110 (or 1.0 field of view), or only inside the inner field of view 111 (or 0 field of view). In some exemplary embodiments, the nanostructure array may be arranged both at the edge of the outer field of view 110 and in the interior of the inner field of view 111.

For the same lens, the nanostructure array may be arranged on only one surface of one of the optical elements, but the present application is not limited thereto. In an example, the nanostructure array may also be arranged simultaneously on the object-side and image-side of one optical element in the lens. Alternatively, the nanostructure array may also be arranged simultaneously on multiple surfaces of multiple optical elements in the lens.

In some exemplary embodiments, the nanostructure array disposed at the edge of the outer field of view may have a higher nanospace fraction than the nanostructure array disposed within the inner field of view. In other words, the nanostructures in the nanostructure array disposed at the edge of the outer field of view may be more dense and the spacing of adjacent nanostructures may be relatively smaller.

Although the structure for correcting chromatic aberration is referred to as a nanostructure array in the present application, it should be understood that adjacent nanostructures in the nanostructure array do not necessarily have a fixed pitch therebetween. In some embodiments, the spacing between the nanostructures may be made the same for the sake of simplifying the design process. In addition, the spacing between the nanostructures can also be intentionally differentiated to limit diffraction effects.

In some exemplary embodiments, the spacing between adjacent nanostructures may be less than 1 micron for modulation of the visible light band. The height of the nanostructures in the direction perpendicular to surface 100 may be in the range of 200-2000 nanometers, provided that the spacing between adjacent nanostructures is less than 1 micron. Additionally, the length (or diameter) of the nanostructures in a direction parallel to the surface 100 may be in the range of 100-1000 nanometers. The ratio of the minimum width to the maximum height of the nanostructure may be greater than 1/15. Satisfying the ratio of the minimum width to the maximum height by 1/15 helps satisfy the required phase adjustment amplitude with ease of manufacturing.

The nanostructures are arranged such that the nanostructures provide different phase modulations at different locations, thereby producing different deflections of incident light. In particular, different phase modulations are achieved by variations in the spatial volume occupied by the nanostructures.

FIGS. 5 and 6 show that 780nm incident light passes through different wavelengthsDifferent changes in phase after the nanostructure of size. In FIGS. 5 and 6, the TiO particles with a height of 900nm and diameters of 100nm and 400nm, respectively, are used ₂ Cylindrical nanostructures are used as an example of nanostructures.

Theoretically, as long as the refractive index of the nanostructure is larger than that of the lens or the filter (e.g., glass or plastic material), the equivalent refractive index of the nanostructure increases with the increase of the space occupied by the nanostructure, so as to generate different modulations on the phase of the outgoing light wave front.

In some exemplary embodiments, the equivalent refractive index may be changed by changing the height of the nanostructure in a direction perpendicular to the surface. Alternatively, the equivalent refractive index can also be varied by varying the length (or diameter) of the nanostructures in a direction parallel to the surface. For the purpose of processing convenience, the length (or diameter) of the nanostructure in the direction parallel to the surface is usually selected to be changed to change the equivalent refractive index, so as to maintain the high uniformity of the nanostructure in the direction perpendicular to the surface.

Fig. 7 schematically shows the phase modulation versus nanostructure space fraction. In FIG. 7, the TiO with a height of 900nm is used ₂ Cylindrical nanostructures are exemplified. Specifically, the diameters of the selected nanostructures are changed within the range of 100-500nm, and the spacing between adjacent nanostructures is changed within the range of 200-600nm, so that the space volume ratio of the nanostructures is changed within the range of 2-40%.

For incident light with 656.3nm wavelength, a curve of phase change with nanostructure space specific volume can be established by methods of strict wave coupling RCWA, finite difference time domain FDTD or finite element FEM, which are well known to those skilled in the art. From such curves, corresponding nanostructures can be selected and arranged according to the desired phase, thereby achieving any desired phase distribution. As can be seen from fig. 7, this change in spatial volume fraction can achieve any phase change of 0-2 pi. The nano-structure arrays with different space volume ratios are arranged at different positions, so that different phase modulation can be provided for light rays at different positions, and selective deflection can be performed on the light rays.

For example, a formula can be utilized

The phase corrections required at different positions d in the radial direction are estimated and the corresponding different sized nanostructures are arranged according to the curve shown in fig. 7, where λ is the wavelength and θ is the deflection angle required to correct for chromatic aberrations.

The choice of θ is based on making the additional polarization added by the nanostructure array cancel out the polarization of the light caused by the chromatic aberration effect bottleneck wavelength. For example, when it is predicted from conventional optical design software in the art that the focus of incident light at a wavelength of 656.3nm on-axis will be deflected by an amount corresponding to about-2 °, the additional deflection provided by the nanostructure array should be made 2 ° to counteract the deflection of light caused by the bottleneck wavelength of chromatic aberration. Thus, an achromatic effect can be achieved.

Fig. 8 and 9 schematically illustrate the deflection of the nanostructure array for different wavelengths of incident light.

To achieve field-selective chromatic aberration correction, the nanostructure array arranged as shown in fig. 4 can implement the deflection of light. As shown in fig. 8, the nanostructure array arranged as shown in fig. 4 can be deflected for incident light with a wavelength of 656.3 nm. For a conventional lens, the required deflection angle is typically small, e.g. less than 5 ° absolute. But for ease of illustration, θ is exaggerated to 10 ° in the example.

Furthermore, the deflection of light achieved by the nanostructure array may be wavelength sensitive. In other words, the nanostructure array can be used to achieve a desired wavelength selectivity. For example, as shown in FIG. 9, the nanostructure array does not deflect incident light at a wavelength of 486.1 nm.

Thus, for the optical lens 10 shown in fig. 1, different nanostructure arrays may be arranged at spatial positions corresponding to the 0 field and the 1.0 field of any one of the lenses or the filter, so as to perform selective chromatic aberration correction on incident light with a wavelength of 656.3 nm.

Under the condition that the refractive index of the nano structure is larger than that of the substrate, the effect of correcting chromatic aberration can be achieved by reasonably setting the spatial distribution of the nano structure. Therefore, the nano-structure may be selected from various high refractive index semiconductor materials such as silicon, germanium, silicon nitride, gallium arsenide, gallium phosphide, and the like, or non-metallic materials such as insulators, but the application is not limited thereto. The nanostructures need to avoid the use of high dissipation metal materials.

The principle of nanostructure phase modulation is the change in equivalent refractive index with volume occupied by space. Therefore, in the case where the phase change curve can be established according to the spatial volume change of the nanostructure, the nanostructure may have various shapes, for example, the nanostructure may be a hemispherical, cubic, columnar, conical, or irregular shaped structure, but the present application is not limited thereto.

When the nanostructure phase modulation scheme is applied to other lenses with chromatic aberration bottlenecks occurring at different fields of view or wavelengths, the positions of the nanostructure arrays arranged on the lenses or the filters and the size of each nanostructure itself can be changed as required.

The preparation of the nano-structure array can select common micro-nano processing technologies such as nano-imprinting, photoetching, electron beam etching, 3D printing, laser direct writing and the like. In some exemplary embodiments, the nanostructure array may be further coated with a conventional antireflection film or a protective film, so as to prevent the penetration of foreign substances.

According to another aspect of the present application, a method of manufacturing an achromatic optical lens is also provided. Fig. 10 schematically shows a block diagram of a method 1000 of manufacturing an achromatic optical lens according to an exemplary embodiment of the present application.

Referring to fig. 10, the method of manufacturing the achromatic optical lens includes:

s1010: arranging a plurality of optical elements on a photosensitive path of an image sensor; and

s1020: and arranging a non-metal micro-nano structure array on at least one surface of one of the optical elements.

In step S1020, a convex non-metallic micro-nano structure array may be disposed on at least one surface of one of the plurality of optical elements based on a dispersion characteristic of incident light reaching the image sensor through the plurality of optical elements. The non-metallic micro-nano structure array may comprise a plurality of micro-nano structures. The volume of space occupied by each micro-nano structure can be changed based on the position of the micro-nano structure on at least one surface, so that the non-metallic micro-nano structure array can apply phase modulation with wavelength selectivity to incident light.

In some embodiments, the wavelength selectivity can be characterized by the non-metallic micro-nano structure array having a deflecting effect on one or more wavelengths of incident light within a wavelength range of 280nm to 2526 nm. Optionally, the incident light may include a first wavelength light and a second wavelength light within a wavelength range of 280nm to 2526nm, and the wavelength selectivity may be characterized in that the degree of deflection of the non-metallic micro-nano structure array for the first wavelength light is significantly greater than the degree of deflection of the non-metallic micro-nano structure array for the second wavelength light.

In some embodiments, the phase modulation applied by the non-metallic micro-nano structure array on incident light can also have field selectivity. Under the condition that the incident light comprises a first visual angle light and a second visual angle light in different visual angles, the visual field selectivity can be embodied as that the deflection degree of the non-metal micro-nano structure array to the first visual angle light is obviously larger than that of the non-metal micro-nano structure array to the second visual angle light.

In some embodiments, the micro-nano structure has a refractive index greater than a refractive index of each of the plurality of optical elements.

In some embodiments, the array of non-metallic micro-nano structures is disposed on an optical element having no optical power. Optionally, the non-metal micro-nano structure array is arranged on a filter sheet without focal power.

The above description is only a preferred embodiment of the present application and is illustrative of the principles of the technology employed. It will be appreciated by a person skilled in the art that the scope of the invention as referred to in the present application is not limited to the embodiments with a specific combination of the above-mentioned features, but also covers other embodiments with any combination of the above-mentioned features or their equivalents without departing from the inventive concept. For example, the above features may be replaced with (but not limited to) features having similar functions disclosed in the present application.

Claims

1. An achromatic optical lens, comprising: an image sensor and a plurality of optical elements disposed on a light sensing path of the image sensor,

wherein at least one surface of one optical element in the plurality of optical elements is provided with a raised non-metal micro-nano structure array,

the nonmetal micro-nano structure array comprises a plurality of micro-nano structures, and the space volume occupied by the micro-nano structures is changed based on the position of the micro-nano structures on the surface, so that the nonmetal micro-nano structure array applies phase modulation with wavelength selectivity to incident light.

2. The achromatic optical lens of claim 1, wherein the wavelength selectivity is characterized by the non-metallic micro-nano structure array having a deflecting effect on one or more wavelengths of light in a wavelength range of 280nm to 2526nm of the incident light.

3. The achromatic optical lens of claim 1, wherein the incident light includes first and second wavelengths in a wavelength range of 280-2526 nm,

the wavelength selectivity is characterized in that the deflection degree of the non-metal micro-nano structure array to the first wavelength light is larger than the deflection degree of the non-metal micro-nano structure array to the second wavelength light.

4. The achromatic optical lens of claim 1, wherein the non-metallic micro-nano structure array has field selectivity for the phase modulation applied to the incident light.

5. The achromatic optical lens of claim 4, wherein the incident light includes first and second viewing angles of light in different viewing angles,

the view field selectivity is characterized in that the deflection degree of the non-metal micro-nano structure array to the first visual angle light is larger than the deflection degree of the non-metal micro-nano structure array to the second visual angle light.

6. The achromatic optical lens of claim 1, wherein a refractive index of the micro-nano structure is greater than a refractive index of each of the plurality of optical elements.

7. The achromatic optical lens according to claim 1, wherein a separation distance between adjacent micro-nano structures in the non-metallic micro-nano structure array is less than 1 μm.

8. An achromatic optical lens according to claim 7, wherein the height of the micro-nano structures in a direction perpendicular to the surface is in the range of 200nm to 2000nm, and the length of the micro-nano structures in a direction parallel to the surface is in the range of 100nm to 1000 nm.

9. The achromatic optical lens of claim 1, wherein the non-metallic micro-nano structure array is disposed on a filter sheet having no optical power.

10. A method of manufacturing an achromatic optical lens, comprising:

arranging a plurality of optical elements on a photosensitive path of an image sensor, an

Providing a raised array of non-metallic micro-nano structures on at least one surface of one of the plurality of optical elements based on dispersion characteristics of incident light that reaches the image sensor through the plurality of optical elements,

the nonmetal micro-nano structure array comprises a plurality of micro-nano structures, and the space volume occupied by the micro-nano structures is changed based on the position of the micro-nano structures on the surface, so that the nonmetal micro-nano structure array applies phase modulation with wavelength selectivity to the incident light.