Achromatic optical lens and method of manufacturing the same

Abstract

The present disclosure provides a kind of achromatic optical lens, it includes: image sensor and the multiple optical elements of being arranged on the photosensitive path of the image sensor.The at least one surface of one optical element in the multiple optical elements is provided with the convex non-metal micro-nano structure array, wherein the non-metal micro-nano structure array includes multiple micro-nano structures, the space volume occupied by the micro-nano structure changes based on the position of the micro-nano structure on the surface is different, so that the non-metal micro-nano structure array is incident light with wavelength selective phase modulation is applied.

Description

Technical Field

[0001] This application relates to the field of optical components, and more specifically, to an optical lens element that corrects chromatic aberration through optical micro / nano structures, an achromatic optical lens including the optical lens element, and a method for manufacturing the same. Background Technology

[0002] Chromatic aberration in optical lenses is a physical phenomenon caused by the inability of different light rays emitted from the same point to focus at the same location on the image plane after passing through the lens. Due to the inherent dispersion effect of the lens materials themselves, this phenomenon cannot be completely eliminated but can only be partially mitigated by using lens materials with lower dispersion.

[0003] The Abbe number is a physical quantity used to describe the dispersion characteristics of materials. Generally, the smaller the Abbe number, the more severe the dispersion phenomenon of the material. However, for the resin materials commonly used in mobile phone lenses, their Abbe numbers are generally below 60, especially for high refractive index resin materials, their Abbe numbers are generally no higher than 30. This makes chromatic aberration a major aberration challenge in current mobile phone lenses.

[0004] Furthermore, with the increasing number of lenses in mobile phone lenses and the wider application of high-refractive-index materials, some mobile phone lenses with significant chromatic aberration can even lead to purple fringing, severely impacting image quality and lens product yield. However, since chromatic aberration involves the intrinsic optical properties of materials, there is currently no solution to this problem; the only approach is to optimize optical parameters to find the optimal solution that minimizes chromatic aberration. Summary of the Invention

[0005] This application provides a solution that can at least overcome or partially overcome at least one of the above-mentioned defects of the prior art.

[0006] On one hand, this application provides an achromatic optical lens, comprising: an image sensor and a plurality of optical elements disposed on the light-sensing path of the image sensor. At least one surface of one of the plurality of optical elements may be provided with a raised array of non-metallic micro / nanostructures. The array of non-metallic micro / nanostructures may include a plurality of micro / nanostructures, wherein the spatial volume occupied by the micro / nanostructures can vary based on the different positions of the micro / nanostructures on the surface, thereby enabling the array of non-metallic micro / nanostructures to apply wavelength-selective phase modulation to the incident light.

[0007] In some exemplary embodiments, the wavelength selectivity can be characterized as the non-metallic micro / nanostructure array having a deflection effect on one or more wavelengths of incident light in the wavelength range of 280 nm to 2526 nm.

[0008] In some exemplary embodiments, the incident light may include a first wavelength light and a second wavelength light in the wavelength range of 280 nm to 2526 nm. The wavelength selectivity can be characterized as the degree to which the non-metallic micro / nanostructure array deflects the first wavelength light is greater than the degree to which the non-metallic micro / nanostructure array deflects the second wavelength light.

[0009] In some exemplary embodiments, the phase modulation applied to the incident light by the non-metallic micro / nanostructure array can have field-selectivity.

[0010] In some exemplary embodiments, the incident light may include a first viewing angle light and a second viewing angle light at different viewing angles. The field selectivity can be characterized as the non-metallic micro / nanostructure array deflecting the first viewing angle light to a greater extent than the non-metallic micro / nanostructure array deflecting the second viewing angle light.

[0011] In some exemplary embodiments, the refractive index of the micro / nano structure may be greater than the refractive index of each of the plurality of optical elements.

[0012] In some exemplary embodiments, the spacing between adjacent micro- and nanostructures in the non-metallic micro- and nanostructure array can be less than 1 μm.

[0013] In some exemplary embodiments, the height of the micro / nanostructure in the direction perpendicular to the surface can be in the range of 200 nm to 2000 nm. Additionally, the length of the micro / nanostructure in the direction parallel to the surface can be in the range of 100 nm to 1000 nm.

[0014] In some exemplary embodiments, the ratio of the minimum length to the maximum height of the micro / nano structure can be greater than 1 / 15.

[0015] In some exemplary embodiments, the non-metallic micro / nanostructure array can be disposed on an optical element that does not have optical power.

[0016] In some exemplary embodiments, the non-metallic micro / nano structure array can be disposed on a filter that does not have optical power.

[0017] On the other hand, this application provides a method for manufacturing an achromatic optical lens, the method comprising: arranging a plurality of optical elements along the light-sensing path of an image sensor; and, based on the dispersion characteristics of incident light reaching the image sensor through the plurality of optical elements, arranging a raised array of non-metallic micro / nanostructures on at least one surface of one of the plurality of optical elements. The array of non-metallic micro / nanostructures may include a plurality of micro / nanostructures, wherein the spatial volume occupied by the micro / nanostructures varies depending on the position of the micro / nanostructures on the surface, thereby enabling the array of non-metallic micro / nanostructures to apply wavelength-selective phase modulation to the incident light.

[0018] In some exemplary embodiments, the wavelength selectivity can be characterized as the non-metallic micro / nanostructure array having a deflection effect on one or more wavelengths of incident light in the wavelength range of 280 nm to 2526 nm.

[0019] In some exemplary embodiments, the incident light may include a first wavelength light and a second wavelength light in the wavelength range of 280 nm to 2526 nm. The wavelength selectivity can be characterized as the degree to which the non-metallic micro / nanostructure array deflects the first wavelength light is greater than the degree to which the non-metallic micro / nanostructure array deflects the second wavelength light.

[0020] In some exemplary embodiments, the phase modulation applied to the incident light by the non-metallic micro / nanostructure array can have field-selectivity.

[0021] In some exemplary embodiments, the incident light may include a first viewing angle light and a second viewing angle light at different viewing angles. The field selectivity is characterized by the non-metallic micro / nanostructure array deflecting the first viewing angle light to a greater extent than the non-metallic micro / nanostructure array deflecting the second viewing angle light.

[0022] In some exemplary embodiments, the refractive index of the micro / nano structure may be greater than the refractive index of each of the plurality of optical elements.

[0023] In some exemplary embodiments, the spacing between adjacent micro-nano structures in the non-metallic micro-nano structure array can be set to less than 1 μm.

[0024] In some exemplary embodiments, the height of the micro / nanostructure in the direction perpendicular to the surface can be set in the range of 200 nm to 2000 nm. Alternatively, the length of the micro / nanostructure in the direction parallel to the surface can be set in the range of 100 nm to 1000 nm.

[0025] In some exemplary embodiments, the ratio of the minimum length to the maximum height of the micro / nano structure can be greater than 1 / 15.

[0026] In some exemplary embodiments, the non-metallic micro / nanostructure array can be disposed on an optical element that does not have optical power.

[0027] In some exemplary embodiments, the non-metallic micro / nano structure array can be disposed on a filter that does not have optical power.

[0028] The achromatic optical lens according to this application has an optical element with a non-metallic micro / nano structure array, which can apply wavelength-selective phase modulation to incident light, thereby correcting the chromatic aberration of incident light at a specific wavelength. Attached Figure Description

[0029] The above and other advantages of embodiments of this application will become apparent from the following detailed description with reference to the accompanying drawings, which are intended to illustrate exemplary embodiments of this application and not to limit them. In the drawings:

[0030] Figure 1 A schematic diagram of the structure of an optical lens in the prior art is shown;

[0031] Figure 2 and Figure 3 They are shown respectively Figure 1 The on-axis chromatic aberration curve and magnification chromatic aberration curve of the optical lens shown;

[0032] Figure 4 A schematic diagram of a nanostructure array according to an exemplary embodiment of this application is shown;

[0033] Figure 5 and Figure 6 The schematic diagrams of the incident photoelectric vector distribution are shown respectively;

[0034] Figure 7 The diagram illustrates the relationship between phase modulation and the space ratio of the nanostructure.

[0035] Figure 8 and Figure 9 The diagrams schematically illustrate the deflection of incident light of different wavelengths by the nanostructure array; and

[0036] Figure 10 A block diagram illustrating a method for manufacturing an achromatic optical lens according to an exemplary embodiment of this application is shown. Detailed Implementation

[0037] To better understand this application, various aspects of this application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of exemplary embodiments of this application and are not intended to limit the scope of this application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0038] It should be noted that in this specification, the terms "first," "second," etc., are used only to distinguish one feature from another and do not imply any limitation on the features. Therefore, without departing from the teachings of this application, the first direction discussed below may also be referred to as the second direction, and vice versa.

[0039] In the accompanying drawings, the thickness, dimensions, and shapes of the components may have been slightly exaggerated for ease of illustration. The drawings are for illustrative purposes only and are not drawn to scale. For example, the shapes of spherical or aspherical surfaces shown in the drawings are illustrated by way of example. That is, the shapes of spherical or aspherical surfaces are not limited to those shown in the drawings.

[0040] Throughout this specification, when an element such as a layer, region, or substrate is described as being "on," "connected to," or "attached to" another element, the element may be directly "on," directly "connected to," or directly "attached to" the other element, or there may be one or more other elements between the element and the other element. Conversely, when an element is described as being "directly on," "directly connected to," or "directly attached to" another element, there may be no other elements between the element and the other element.

[0041] Spatial relative terms such as “above,” “above,” “below,” and “below” may be used in this application for descriptive convenience to describe the relationship of one element relative to another, as shown in the accompanying drawings. In addition to covering the orientation depicted in the drawings, these spatial relative terms are intended to also cover different orientations of the device in use or operation. For example, if the device in the drawings is flipped, an element described as “above” or “above” another element would be “below” or “below” that other element. Thus, depending on the spatial orientation of the device, the term “above” covers both “above” and “below” orientations. The device may also be oriented in other ways (e.g., rotated 90 degrees or in other orientations), and the spatial relative terms used in this application should be interpreted accordingly.

[0042] It should also be understood that the terms "comprising," "including," "having," "containing," and / or "comprising," when used in this specification, indicate the presence of the stated features, elements, and / or components, but do not exclude the presence of one or more other features, elements, components, and / or combinations thereof. Furthermore, when expressions such as "at least one of..." appear after a list of listed features, they modify all features in the list, not just individual elements. Additionally, when describing embodiments of this application, the word "may" is used to mean "one or more embodiments of this application." Furthermore, the term "exemplary" is intended to refer to an example or illustration.

[0043] As used herein, the words “approximately,” “about,” and similar terms are used as terms indicating approximation rather than degree, and are intended to describe inherent biases in measurements or calculations that can be recognized by one of ordinary skill in the art.

[0044] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms (e.g., those defined in common dictionaries) shall be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and shall not be interpreted in an idealized or overly formal sense, unless expressly so specified herein.

[0045] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. Furthermore, unless explicitly limited or contradicted by the context, the specific steps included in the methods described in this application are not limited to the order in which they are described, but can be performed in any order or in parallel.

[0046] Exemplary embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0047] Optical lenses in the prior art may include multiple lens elements, optical filters, and an image sensor. The multiple lens elements may all be made of resin or glass. The resin or glass material forming the lens typically has an Abbe number of no more than 60.

[0048] Figure 1 A schematic diagram of the structure of an optical lens 10 in the prior art is shown.

[0049] like Figure 1As shown, the example optical lens 10 has eight lenses E1-E8 and an infrared filter E9, but this application is not limited to this. Those skilled in the art will anticipate that an optical lens may include more or fewer lenses and is not limited to the case shown in the figure. The filter E9 is also not limited to an infrared filter; in some examples, the filter E9 may also be a visible filter, a bandpass filter, a cutoff filter, a short-pass filter, a long-pass filter, etc.

[0050] Eight lenses E1-E8 and an infrared filter E9 are arranged sequentially from the object side to the image side along the optical axis of the optical lens 10. Each of the lenses E1-E8 and the infrared filter E9 has an object-side surface near the object side and an image-side surface near 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.

[0051] An image sensor is positioned at the imaging surface S19. The image sensor 130 can be a CCD or a CMOS sensor, which is used to convert the received light signals into electrical signals. Light rays from the object can pass through surfaces S1-S18 sequentially and finally form an image on the imaging surface S19.

[0052] The optical lens 10 may also include an aperture stop STO for limiting the beam.

[0053] Due to the inherent dispersion characteristics of the lens material and the influence of the lens structure, chromatic aberration will occur on the imaging surface S19, and the chromatic aberration will change with the position of the field of view and the wavelength of the incident light. Figure 2 and Figure 3 They are shown respectively Figure 1 The on-axis chromatic aberration curve and magnification chromatic aberration curve of the optical lens.

[0054] like Figure 2 and Figure 3 As shown, the chromatic aberration curves for different wavelengths differ from each other. For example, the chromatic aberration at some wavelengths can be significantly higher than that at other wavelengths. Furthermore, for some fields of view (e.g., the inner field of view), the consistency of chromatic aberration between different wavelengths is relatively good; while for other fields of view (e.g., the outer field of view), the chromatic aberration between different wavelengths may suddenly increase, creating a bottleneck.

[0055] As can be observed from the accompanying drawings, the chromatic aberration of the example optical lens 10 is most severe at the 1.0 field of view and for incident light at a wavelength of 656.3 nm. Therefore, it is especially necessary to selectively correct the chromatic aberration at the 1.0 field of view and for incident light at a wavelength of 656.3 nm, while other wavelengths and fields of view can be corrected to a smaller extent or not at all.

[0056] Those skilled in the art should understand that different lenses have different chromatic aberration curves. Therefore, for different lenses, similar bottlenecks may occur at other fields of view or for incident light of other wavelengths, thus requiring corresponding corrections to improve image quality. However, such selective correction is difficult to perform without affecting other optical properties of the lens. In traditional optical design methods, one can only find a compromise range with relatively small chromatic aberration by changing the parameters of each lens element, but the correction effect for chromatic aberration is not ideal.

[0057] According to Fermat's principle, light travels along the actual path where the optical path is minimized. Let the total optical path of light along the actual propagation path between points A and B be... Let n(r) be the refractive index distribution along the propagation path r. Then, the total optical path can be expressed in phase form as follows: k0 is the vacuum wavenumber. If the interface between two media through which light propagates introduces Φ(r) to the light wave... s The phase jump of ) is the position vector r on the interface. s If the function is given, then the total phase corresponding to the actual propagation path of the light wave at points A and B is:

[0058]

[0059] In the two-dimensional case, assuming the light wave originates from a source with a refractive index of n... i The medium incident on the refractive index n t In the medium, we can conclude that:

[0060]

[0061] The above equation is the generalized law of refraction. Compared to Snell's formula, the above equation introduces... The term dφ / dx in this term is the phase gradient along the interface direction on the plane defined by the incident and outgoing light.

[0062] According to Equation 2, the classical Snell formula is only a special case of the generalized law of refraction under the condition that the phase gradient is zero. If a suitable phase gradient is introduced into the incident light at the interface, the outgoing light can be refracted in any direction. That is to say, the direction of light refraction 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 into the incident light field at the interface.

[0063] Based on the above principles, this application achieves achromatic correction by arranging a non-metallic micro / nanostructure array on any surface of the lens or filter (i.e., any surface among surfaces S1-S18) other than the imaging surface S19. The non-metallic micro / nanostructure array exhibits wavelength selectivity and can be arranged at the desired field-of-view location for field-selective correction. The non-metallic micro / nanostructure array is also referred to below as a nanostructure array.

[0064] In particular, since the filter does not have optical power, arranging the non-metallic micro-nano structure array on the filter is more conducive to obtaining better achromatic effect than arranging the non-metallic micro-nano structure array on the lens with optical power.

[0065] Figure 4 A schematic diagram of a nanostructure array according to an exemplary embodiment of this application is shown.

[0066] like Figure 4 As shown, the nanostructure array can be disposed on surface 100. Surface 100 can be any of surfaces S1-S18. Depending on the needs, the nanostructure array can be arranged at corresponding positions in the desired field of view on surface 100. For example, nanostructure array 120 can be arranged at the edge of the outer field of view 110 on surface 100, indicated by the outer dashed box. Alternatively, nanostructure array 121 can be arranged inside the inner field of view 111 on surface 100, indicated by the inner dashed box.

[0067] For the same surface, the nanostructure array can be arranged only at the edge of the outer field of view 110 (or in the 1.0 field of view), or only inside the inner field of view 111 (or in the 0 field of view). In some exemplary embodiments, the nanostructure array can be arranged simultaneously at the edge of the outer field of view 110 and inside the inner field of view 111.

[0068] For the same lens, a nanostructure array can be arranged on only one surface of one optical element, but this application is not limited to this. In the example, a nanostructure array can also be arranged simultaneously on both the object side and the image side of one optical element in the lens. Alternatively, a nanostructure array can be arranged simultaneously on multiple surfaces of multiple optical elements in the lens.

[0069] In some exemplary embodiments, nanostructure arrays arranged at the edge of the outer field of view can have a higher nanoscale space ratio compared to nanostructure arrays arranged within the inner field of view. In other words, the nanostructures in the nanostructure array arranged at the edge of the outer field of view can be more densely packed, and the spacing between adjacent nanostructures can be relatively smaller.

[0070] Although the structure used to correct chromatic aberration is referred to as a nanostructure array in this application, it should be understood that the spacing between adjacent nanostructures in a nanostructure array is not necessarily fixed. In some embodiments, the spacing between nanostructures may be made the same for the purpose of simplifying the design process. In addition, the spacing between nanostructures may be intentionally made different to limit diffraction effects.

[0071] In some exemplary embodiments, the spacing between adjacent nanostructures can be less than 1 micrometer for modulation in the visible light band. With the spacing between adjacent nanostructures less than 1 micrometer, the height of the nanostructure in the direction perpendicular to surface 100 can be in the range of 200-2000 nanometers. Additionally, the length (or diameter) of the nanostructure in the direction parallel to surface 100 can be in the range of 100-1000 nanometers. The ratio of the minimum width to the maximum height of the nanostructure can be greater than 1 / 15. A minimum width to maximum height ratio of 1 / 15 helps to meet the required phase modulation amplitude while facilitating fabrication.

[0072] Nanostructures are arranged such that they provide different phase modulations at different locations, thereby causing different deflections of incident light. Specifically, different phase modulations are achieved by varying the spatial volume occupied by the nanostructures.

[0073] Figure 5 and Figure 6 The different phase changes of 780nm incident light after passing through nanostructures of different sizes are shown. Figure 5 and Figure 6 In this study, a TiO2 cylindrical nanostructure with a height of 900 nm and diameters of 100 nm and 400 nm is used as an example of a nanostructure.

[0074] In theory, as long as the refractive index of the nanostructure is greater than that of the lens or filter (e.g., glass or plastic), its equivalent refractive index will increase as the volume occupied by the nanostructure increases, thereby producing different modulations on the phase of the outgoing light wavefront.

[0075] In some exemplary embodiments, the equivalent refractive index can be changed by altering the height of the nanostructure in the direction perpendicular to the surface. Alternatively, the equivalent refractive index can also be changed by altering the length (or diameter) of the nanostructure in the direction parallel to the surface. For ease of fabrication, changing the length (or diameter) of the nanostructure in the direction parallel to the surface is typically chosen to change the equivalent refractive index, thereby maintaining the consistency of the height of the nanostructure in the direction perpendicular to the surface.

[0076] Figure 7 The diagram schematically illustrates the relationship between phase modulation and the spatial proportion of the nanostructure. Figure 7 In this example, a TiO2 cylindrical nanostructure with a height of 900 nm is used. Specifically, the diameter of the nanostructure is varied in the range of 100-500 nm, and the spacing between adjacent nanostructures is varied in the range of 200-600 nm, thereby changing the spatial volume ratio of the nanostructure in the range of 2% to 40%.

[0077] For incident light at a wavelength of 656.3 nm, curves depicting the phase change as a function of the spatial proportion of the nanostructure can be established using methods well-known to those skilled in the art, such as strictly coupled wave-wave (RCWA), finite-difference time-domain (FDTD), or finite element method (FEM). Based on these curves, corresponding nanostructures can be selected and arranged according to the desired phase, thereby achieving any desired phase distribution. Figure 7 It is evident that this change in spatial volume ratio can achieve arbitrary phase changes from 0 to 2π. By placing nanostructure arrays with different spatial volume ratios at different locations, different phase modulations can be provided for light at different locations, thus enabling selective deflection of light.

[0078] For example, formulas can be used To estimate the required phase correction at different radial positions d, and based on, as Figure 7 The curves shown correspond to nanostructures of different sizes, where λ is the wavelength and θ is the deflection angle required to correct chromatic aberration.

[0079] The choice of θ is based on ensuring that the additional deflection provided by the nanostructure array cancels out the deflection of light caused by the bottleneck wavelength of the chromatic aberration effect. For example, if conventional optical design software in the art predicts that the focal point of the incident light at a wavelength of 656.3 nm on the axis will exhibit a deflection of approximately -2°, then the additional deflection provided by the nanostructure array should be 2° to cancel out the deflection of light caused by the bottleneck wavelength of the chromatic aberration effect. In this way, an achromatic effect can be achieved.

[0080] Figure 8 and Figure 9The diagram illustrates how the array of nanostructures deflects incident light of different wavelengths.

[0081] To achieve selective chromatic aberration correction within the field of view, such as Figure 4 The array of nanostructures shown can deflect light. For example... Figure 8 As shown, Figure 4 The array of nanostructures shown can deflect incident light at a wavelength of 656.3 nm. For conventional lenses, the required deflection angle is typically very small, for example, less than 5° in absolute terms. However, for ease of illustration, θ is exaggerated to 10° in the example.

[0082] Furthermore, the light deflection achieved by nanostructure arrays can be wavelength-sensitive. In other words, nanostructure arrays can be used to achieve desired wavelength selectivity. For example, as... Figure 9 As shown, the nanostructure array does not deflect incident light at a wavelength of 486.1 nm.

[0083] Therefore, in response to Figure 1 The optical lens 10 shown can be arranged with different nanostructure arrays at any of its lenses or at the spatial positions corresponding to the 0 field of view and the 1.0 field of view of the filter, so as to selectively correct the chromatic aberration of incident light with a wavelength of 656.3nm.

[0084] When the refractive index of the nanostructure is greater than that of the substrate, a chromatic aberration correction effect can be achieved by rationally setting the spatial distribution of the nanostructure. Therefore, various high-refractive-index semiconductor materials or insulating non-metallic materials such as silicon, germanium, silicon nitride, gallium arsenide, and gallium phosphide can be used for the nanostructure, but this application is not limited to these. High-dissipation metal materials should be avoided in the nanostructure.

[0085] The principle of phase modulation of nanostructures is based on the change in equivalent refractive index with the volume occupied by the space. Therefore, when a phase change curve can be established based on the change in the spatial volume of the nanostructure, the nanostructure can have various shapes. For example, the nanostructure can be hemispherical, cubic, cylindrical, conical, or irregularly shaped, but this application is not limited to these.

[0086] When applying the nanostructure phase modulation scheme to other lenses where the chromatic aberration bottleneck occurs at different fields of view or wavelengths, the position of the nanostructure array on the lens or filter, as well as the size of each nanostructure, can be changed as needed.

[0087] The fabrication of nanostructure arrays can utilize common micro / nano fabrication techniques such as nanoimprinting, photolithography, electron beam etching, 3D printing, and laser direct writing. In some exemplary embodiments, conventional antireflective or protective films can be further coated onto the nanostructure array to reduce reflection or protect against the intrusion of external substances.

[0088] According to another aspect of this application, this application also provides a method for manufacturing an achromatic optical lens. Figure 10 A block diagram illustrating a method 1000 for manufacturing an achromatic optical lens according to an exemplary embodiment of this application is shown.

[0089] See Figure 10 The manufacturing methods for achromatic optical lenses include:

[0090] S1010: Multiple optical elements are arranged along the light-sensing path of the image sensor; and

[0091] S1020: An array of non-metallic micro / nano structures is disposed on at least one surface of one of a plurality of optical elements.

[0092] In step S1020, a raised array of non-metallic micro / nanostructures can be formed on at least one surface of one of the multiple optical elements, based on the dispersion characteristics of the incident light reaching the image sensor through the multiple optical elements. The array of non-metallic micro / nanostructures can include multiple micro / nanostructures. The spatial volume occupied by each micro / nanostructure can vary depending on its position on at least one surface, thereby allowing the array of non-metallic micro / nanostructures to apply, for example, wavelength-selective phase modulation to the incident light.

[0093] In some embodiments, wavelength selectivity can be characterized as the non-metallic micro / nanostructure array deflecting one or more wavelengths of incident light within the wavelength range of 280 nm to 2526 nm. Optionally, the incident light may include a first wavelength and a second wavelength within the wavelength range of 280 nm to 2526 nm, and wavelength selectivity can be characterized as the non-metallic micro / nanostructure array deflecting the first wavelength light to a significantly greater extent than the non-metallic micro / nanostructure array deflecting the second wavelength light.

[0094] In some implementations, the phase modulation applied to the incident light by the non-metallic micro / nanostructure array can also exhibit field-view selectivity. When the incident light includes a first-view light and a second-view light at different viewing angles, the field-view selectivity can specifically manifest as the non-metallic micro / nanostructure array deflecting the first-view light to a significantly greater degree than the non-metallic micro / nanostructure array deflecting the second-view light.

[0095] In some implementations, the refractive index of the micro / nano structure is greater than the refractive index of each of the multiple optical elements.

[0096] In some embodiments, the non-metallic micro / nanostructure array is disposed on an optical element that does not have optical power. Alternatively, the non-metallic micro / nanostructure array is disposed on a filter that does not have optical power.

[0097] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. An achromatic optical lens comprising: An image sensor and a plurality of optical elements disposed on an optical path of the image sensor, the plurality of optical elements comprising a filter without optical power, wherein the filter is provided with a raised non-metallic micro-nano structure array disposed on a 1.0 field of view of at least one surface of the filter, or the non-metallic micro-nano structure array is disposed on a 1.0 field of view and a 0 field of view of at least one surface of the filter, wherein the non-metallic micro-nano structure array comprises a plurality of micro-nano structures, a spatial volume occupied by the micro-nano structures changes based on different positions of the micro-nano structures on the surface, so that the non-metallic micro-nano structure array applies wavelength-selective phase modulation to incident light, wherein the incident light comprises light at a first viewing angle and light at a second viewing angle, the phase modulation applied by the non-metallic micro-nano structure array to the incident light has a field of view selectivity, the field of view selectivity is characterized by a degree of deflection of the non-metallic micro-nano structure array to light at the first viewing angle being greater than a degree of deflection of the non-metallic micro-nano structure array to light at the second viewing angle, the first viewing angle being greater than the second viewing angle, the first viewing angle corresponding to the 1.0 field of view, and the second viewing angle corresponding to the 0 field of view.

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

3. The achromatic optical lens of claim 1, wherein, The incident light comprises first wavelength light and second wavelength light within a wavelength range of 280 nm to 2526 nm, The wavelength selectivity is characterized by a degree of deflection of the non-metallic micro-nano structure array to the first wavelength light being greater than a degree of deflection of the non-metallic micro-nano structure array to the second wavelength light.

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

5. The achromatic optical lens of claim 1, wherein, The spacing distance between adjacent micro-nano structures in the non-metallic micro-nano structure array is less than 1 μm.

6. The achromatic optical lens of claim 5, wherein, The height of the micro-nano structure in a direction perpendicular to the surface is within a range of 200 nm to 2000 nm, and the length of the micro-nano structure in a direction parallel to the surface is within a range of 100 nm to 1000 nm.

7. The achromatic optical lens of claim 6, wherein, The ratio of the minimum length of the micro-nano structure to the maximum height is greater than 1 / 15.

8. A manufacturing method of an achromatic optical lens, comprising: disposing a plurality of optical elements on an optical path of an image sensor, the plurality of optical elements comprising a filter without optical power, and based on a dispersion characteristic of incident light reaching the image sensor through the plurality of optical elements, a raised non-metallic micro-nano structure array is disposed on the filter, the non-metallic micro-nano structure array is disposed on a 1.0 field of view of at least one surface of the filter, or the non-metallic micro-nano structure array is disposed on a 1.0 field of view and a 0 field of view of at least one surface of the filter, The non-metal micro-nano structure array includes a plurality of micro-nano structures, and a space volume occupied by the micro-nano structures changes based on different positions of the micro-nano structures on the surface, so that the non-metal micro-nano structure array applies wavelength-selective phase modulation to the incident light, The incident light includes light at a first viewing angle and light at a second viewing angle, the phase modulation applied by the non-metal micro-nano structure array to the incident light is field-of-view selective, the field-of-view selectivity is characterized in that the degree of deflection of the non-metal micro-nano structure array to the light at the first viewing angle is greater than the degree of deflection of the non-metal micro-nano structure array to the light at the second viewing angle, the first viewing angle is greater than the second viewing angle, the first viewing angle corresponds to the 1.0 field of view, and the second viewing angle corresponds to the 0 field of view.

9. The manufacturing method according to claim 8, wherein, The wavelength selectivity is characterized in that the non-metal micro-nano structure array has a deflection effect on light at one or more wavelengths in a wavelength range of 280 nm to 2526 nm in the incident light.

10. The manufacturing method according to claim 8, wherein, The incident light includes first wavelength light and second wavelength light in a wavelength range of 280 nm to 2526 nm, The wavelength selectivity is characterized in that the degree of deflection of the non-metal micro-nano structure array to the first wavelength light is greater than the degree of deflection of the non-metal micro-nano structure array to the second wavelength light.

11. The manufacturing method according to claim 8, wherein, The refractive index of the micro-nano structure is greater than the refractive index of each optical element in the plurality of optical elements.

12. The manufacturing method according to claim 8, wherein, The spacing distance between adjacent micro-nano structures in the non-metal micro-nano structure array is set to be less than 1 μm.

13. The manufacturing method of claim 12, wherein, The height of the micro-nano structure in the direction perpendicular to the surface is set to be in a range of 200 nm to 2000 nm, and the length of the micro-nano structure in the direction parallel to the surface is set to be in a range of 100 nm to 1000 nm.

14. The manufacturing method according to claim 13, wherein, The ratio of the minimum length of the micro-nano structure to the maximum height is greater than 1 / 15.

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