Dual engineered microsphere lens assembly and optical imaging system

Abstract

This application relates to the field of optical imaging technology, specifically disclosing a dual engineered microsphere lens assembly and an optical imaging system. The dual engineered microsphere lens assembly includes two engineered microspheres coaxially arranged at the bottom and top. The engineered microspheres are planar-spherical microlenses fabricated using a complete spherical microsphere as the initial material through any method. The thickness of the bottom engineered microsphere satisfies a specific geometric relationship, ensuring that it can form a magnified virtual image of the sample in an atmospheric environment. This design overcomes the limitation that traditional high-refractive-index microspheres need to be immersed in liquid to work. Thus, it realizes non-contact real-time imaging in an atmospheric environment, has the ability to resolve sub-diffraction-limited structures, high optical magnification, simple structure, low cost, and effectively avoids sample contamination.

Description

Technical Field

[0001] This invention relates to the field of optical imaging technology, and in particular to an imaging method for a dual engineered microsphere lens group and an infrared microsphere optical nanoimaging system. Background Technology

[0002] Optical microscopy, compared to electrical microscopy, offers advantages such as requiring no vacuum environment and being able to observe living samples, leading to its wide application in biotechnology, electronic information, research, and teaching. However, limited by the diffraction effect of light waves, the resolution of traditional optical microscopes is difficult to reach half the wavelength of the incident light, failing to meet the demands for higher-precision characterization. In recent years, optical microsphere nanomicroscopy has gained widespread attention due to its advantages such as being label-free, non-invasive, and having high resolution. Initially, this technology was limited by the use of single microspheres, resulting in limited optical magnification. To overcome this challenge, researchers proposed the concept of microsphere composite lenses, which cascade two or more microspheres along the optical axis of the microscopy system, improving the magnification and imaging field of view of the microsphere microscope. Most dual-microsphere composite lenses employ a "virtual image first, then real image" working principle. The microsphere closer to the sample at the bottom forms a magnified virtual image of the sample, which is then further magnified into a next-order real image by the top microsphere. To further improve the imaging performance of microsphere composite lenses, the following requirements are generally met: the refractive index of the bottom microsphere should be as high as possible to allow the first-order virtual image to carry more feature information; the working distance of the top microsphere should be as large as possible to match the position of the first-order virtual image. However, when the refractive index of the bottom microsphere is greater than 2, its focal point is no longer outside the microsphere, and it cannot form a virtual image of the sample. Some researchers have attempted to reduce the relative refractive index between the microsphere lens assembly and the environment by immersing the microsphere lens assembly in a high-refractive-index liquid, thus enabling the high-refractive-index microspheres to form a magnified virtual image of the sample being observed. However, in this method, there is a risk of sample damage from the liquid. Furthermore, most microsphere composite lens assemblies operate in contact mode, meaning that the bottom microspheres are randomly sprinkled onto the surface of the sample, which is not only detrimental to observing the morphology of specific locations but also easily leads to sample contamination due to microsphere adhesion. Therefore, a microsphere composite lens assembly that can operate in an atmospheric environment, is non-contact, has high resolution, and high magnification is needed. Summary of the Invention

[0003] The present invention aims to at least partially solve one of the technical problems in the aforementioned technologies. Therefore, one objective of the present invention is to propose a dual engineered microsphere lens assembly capable of non-contact real-time imaging in an atmospheric environment, possessing the ability to resolve sub-diffraction-limited structures, high optical magnification, simple structure, and low cost.

[0004] The second objective of this invention is to provide an optical imaging system.

[0005] To achieve the above objectives, the first aspect of this invention provides a dual engineered microsphere lens assembly, comprising: a first engineered microsphere, which is a planar-spherical microlens; and a second engineered microsphere, which is also a planar-spherical microlens, coaxially arranged with the first engineered microsphere, positioned below the first engineered microsphere, with the plane of the second engineered microsphere facing the sample to be observed; and the thickness of the second engineered microsphere satisfies the following relationship:

[0006]

[0007] in, Indicates the thickness of the second engineered microsphere. This represents the radius of the second engineered microsphere. This represents the refractive index of the second engineered microsphere.

[0008] The dual engineered microsphere lens group proposed in this invention has the following advantages: it can realize non-contact real-time imaging in an atmospheric environment, has the ability to resolve sub-diffraction-limited structures, has high optical magnification, simple structure, and low cost.

[0009] In addition, the dual engineered microsphere lens assembly proposed according to the present invention may also have the following additional technical features:

[0010] Optionally, the positions of the image planes formed by the dual engineered microsphere lenses satisfy the following relationship:

[0011]

[0012] in, This represents the distance from the first-order virtual image surface formed by the second engineered microsphere to the vertex on the second engineered microsphere. This represents the distance from the second-order real image plane formed by the first engineered microsphere to the vertex on the second engineered microsphere; This represents the radius of the first engineered microsphere. Indicates the refractive index of the first engineered microsphere. This indicates the thickness of the first engineered microsphere. It indicates the refractive index of the environment.

[0013] Optionally, the magnification of the dual engineered microsphere lens group is greater than 10x, and satisfies the following relationship:

[0014]

[0015] in, This indicates the magnification of the dual engineered microsphere lens assembly. This indicates the magnification of the second engineered microsphere. This indicates the magnification of the first engineered microsphere.

[0016] Optionally, the plane of the first engineered microsphere may face or be away from the sample to be observed.

[0017] Optionally, the diameter of the second engineered microsphere is greater than 2 μm and less than 500 μm.

[0018] Optionally, the diameter of the second engineered microsphere is 25 μm.

[0019] Optionally, the diameter of the first engineered microsphere is 90 μm.

[0020] Optionally, the radius ratio of the dual-engineered microspheres satisfies the following relationship:

[0021]

[0022] in, Indicates the thickness of the second engineered microsphere With radius The ratio, Indicates the thickness of the first engineered microsphere With radius The ratio of .

[0023] To achieve the above objectives, a second aspect of the present invention provides an optical imaging system comprising the aforementioned dual engineered microsphere lens group.

[0024] In addition, the optical imaging system proposed above according to the present invention may also have the following additional technical features:

[0025] Optionally, the optical imaging system further includes: an illumination source; an optical microscopy system, which adjusts the illumination source to reach the sample to be observed, and converts the reflected or transmitted light from the sample to obtain an imaging beam; a microsphere clamping device, wherein the dual engineered microsphere lens group is positioned between the optical microscopy system and the sample to be observed via the microsphere clamping device to collect the reflected or transmitted light from the sample; a three-dimensional displacement platform, which controls the relative position between the sample to be observed and the dual engineered microsphere lens group; and a camera, which is mounted on the optical microscopy system and can acquire high-resolution, high-magnification images based on the imaging beam.

[0026] Optionally, the stepping accuracy of the three-dimensional displacement platform on the XY axis is less than or equal to 50 nm, and the stepping accuracy on the Z axis is less than or equal to 10 nm. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the imaging of a dual engineered microsphere lens assembly according to an embodiment of the present invention;

[0028] Figure 2 This is a schematic diagram of an optical imaging system equipped with a dual engineered microsphere lens group according to an embodiment of the present invention;

[0029] Figure 3 This is a graph showing the results of calculating the magnification of a dual engineered microsphere lens group using the finite-difference time-domain method according to an embodiment of the present invention, wherein... Figure 3 (a) is a magnified image of a top engineered microsphere with a diameter of 60 μm and a refractive index of 1.5; Figure 3 (b) is a magnified view of the top engineered microsphere with a diameter of 70 μm and a refractive index of 1.5; Figure 3 (c) is a magnified image of the top engineered microsphere with a diameter of 70 μm, a thickness of 60 μm, and a refractive index of 1.5.

[0030] Figure 4 This is an imaging result diagram of a dual engineered microsphere lens assembly according to an embodiment of the present invention, wherein, Figure 4 (a) is a scanning electron microscope image of the sample to be observed. Figure 4 (b) is an image obtained by observing the sample under test using a 50× objective lens (NA~0.6). Figure 4 (c) is an image obtained by observing the sample under test with a 100× objective lens (NA~0.8). Figure 4 (d) shows the imaging results of the sample under test using a dual engineered microsphere lens assembly. Figure 4 (e) shows the imaging results of the sample under test using a single engineered microsphere lens assembly;

[0031] Figure 5 This is a schematic diagram of the outer focal length according to an embodiment of the present invention, wherein, Figure 5 (a) is a schematic diagram of the outer focal length of the complete microsphere. Figure 5 (b) is a schematic diagram of the outer focal length of an engineered super-microsphere;

[0032] Figure 6 This is a schematic diagram illustrating the relationship between the outer focal length and the diameter and thickness according to an embodiment of the present invention;

[0033] Figure 7 This is a schematic diagram of the outer focal length of different structures under FDTD simulation according to an embodiment of the present invention, wherein, Figure 7 (a) is a schematic diagram of the outer focal length of the complete microsphere. Figure 7 (b) and Figure 7 (c) is a schematic diagram of the outer focal length of an engineered super-microsphere.

[0034] Explanation of reference numerals in the attached figures: 1. Illumination source; 2. Condenser lens; 3. Aperture stop; 4. Field stop; 5. Condenser lens; 6. Polarizer; 7. Camera; 8. Sleeve lens; 9. Analyzer; 10. Beam splitter; 11. Objective lens; 12. Microsphere clamping device; 13. Double engineered microsphere lens group; 14. Three-dimensional displacement platform; 15. First engineered microsphere; 16. Second engineered microsphere. Detailed Implementation

[0035] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0036] To better understand the above technical solutions, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the invention to those skilled in the art.

[0037] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0038] refer to Figure 1 As shown, the dual engineered microsphere lens group proposed in this embodiment of the invention includes a first engineered microsphere 15 and a second engineered microsphere 16.

[0039] The first engineered microsphere 15 is a planar-spherical microlens, with its planar surface facing the sample to be observed. The second engineered microsphere 16 is also a planar-spherical microlens, coaxially arranged with the first engineered microsphere 15 and positioned below it, with its planar surface facing the sample to be observed. Furthermore, the thickness of the second engineered microsphere 16 satisfies the following relationship:

[0040]

[0041] in, Indicates the thickness of the second engineered microsphere. This represents the radius of the second engineered microsphere. This represents the refractive index of the second engineered microsphere.

[0042] In other words, the first engineered microsphere 15 is the top engineered microsphere, and the second engineered microsphere 16 is the bottom engineered microsphere. They are stacked coaxially along the optical axis. Both engineered microspheres have a spherical cap structure, with one side being a spherical surface and the other side being a plane, with the plane facing the sample to be observed.

[0043] It should be noted that engineered microsphere lenses refer to lenses that use complete spherical microspheres as the initial material and intentionally change their surface morphology or overall geometry (e.g., to create planes, steps, arrays or other microstructures) through micro-nano fabrication techniques (such as etching, cutting, deposition, etc.) to obtain optical properties or functions that the original microspheres do not possess.

[0044] Furthermore, the imaging process of the dual engineered microsphere lens group can be understood as follows: First, the bottom engineered microsphere lens images the sample to be observed. At this time, the sample to be observed forms a first-order magnified virtual image through the bottom engineered microsphere, and the image plane is located below the sample. Subsequently, the first-order magnified virtual image serves as the imaging object of the top engineered microsphere lens, and is imaged by the top engineered microsphere lens, with the image plane located above the dual engineered microsphere lens group, forming a second-order magnified real image. The position of the image plane can be calculated using the following formula during the two imaging processes:

[0045]

[0046] in, This represents the distance from the first-order virtual image surface formed by the second engineered microsphere to the vertex on the second engineered microsphere. This represents the distance from the second-order real image plane formed by the first engineered microsphere to the vertex on the second engineered microsphere; This represents the radius of the first engineered microsphere. Indicates the refractive index of the first engineered microsphere. This indicates the thickness of the first engineered microsphere. It indicates the refractive index of the environment.

[0047] Thus, the reflected or transmitted light carrying information about the sample to be observed is amplified by a dual engineered microsphere lens group, which is characterized by the ability to resolve sub-diffraction-limited structures.

[0048] As an example, the magnification of the dual engineered microsphere lens group is greater than 10x, and satisfies the following relationship:

[0049]

[0050] in, This indicates the magnification of the dual engineered microsphere lens assembly. This indicates the magnification of the second engineered microsphere. This indicates the magnification of the first engineered microsphere.

[0051] As an example, the diameter of the second engineered microsphere is greater than 2 μm and less than 500 μm.

[0052] Specifically, the diameter of the second engineered microsphere is 25 μm.

[0053] As an example, the diameter of the first engineered microsphere is 90 μm.

[0054] As an example, the radius ratio of the dual-engineered microspheres satisfies the following relationship:

[0055]

[0056] in, Indicates the thickness of the second engineered microsphere With radius The ratio, Indicates the thickness of the first engineered microsphere With radius The ratio of .

[0057] As an example, the first engineered microsphere is made of borosilicate glass, and the second engineered microsphere is made of barium titanate glass.

[0058] As an example, the refractive index of the second engineered microsphere is configured to form a high-quality virtual image of the sample in an atmospheric environment.

[0059] In summary, the dual engineered microsphere lens assembly of this application can resolve sub-diffraction-limited structures, with a resolution exceeding that of traditional optical microscopes; it can achieve an optical magnification of more than 10 times, and when combined with the objective lens, it can significantly improve the optical magnification of the microscopy system; it enables non-contact real-time imaging in atmospheric environments, avoiding sample contamination; the dual engineered microsphere lens assembly is easy to couple with the objective lens, has a simple structure, and is inexpensive.

[0060] refer to Figure 2 As shown, this embodiment of the invention also proposes an optical imaging system, including an illumination source 1, an optical microscopy system, a microsphere clamping device 12, a three-dimensional displacement platform 14, and a camera 7. The optical microscopy system controls the illumination source 1 to reach the sample to be observed, and converts the reflected or transmitted light from the sample to obtain an imaging beam. A dual engineered microsphere lens group is positioned between the optical microscopy system and the sample to be observed via the microsphere clamping device 12 to collect the reflected or transmitted light from the sample. The three-dimensional displacement platform 14 controls the relative position between the sample and the dual engineered microsphere lens group 13. The camera 7 is mounted on the optical microscopy system and can acquire high-resolution, high-magnification images based on the imaging beam.

[0061] As an example, the lighting source can be a monochromatic blue light source in the visible light range.

[0062] It should be noted that the optical microscopy system is used to magnify and acquire images magnified by a double engineered microsphere lens group, including the illumination optical path, the imaging optical path, and the photodetector.

[0063] The lighting path includes an adjustable aperture and a polarizer.

[0064] Among them, the objective lens in the imaging optical path is a long working distance objective lens.

[0065] The size of the photodetector pixel should be less than 2μm×2μm.

[0066] It should be noted that the microsphere clamping device 12 is used to fix the double engineered microsphere lens group 13 and can controllably bring the double engineered microsphere lens group 13 close to or in contact with the surface of the sample to be observed; the microsphere clamping device 12 can be configured as an independent device separate from the objective lens 11 in the optical microscope system or as a device integrated with the objective lens 11.

[0067] Specifically, after light is emitted from the illumination source 1, it passes sequentially through the condenser lens 2, aperture stop 3, field stop 4, condenser lens 5, polarizer 6, beam splitter 10, objective lens 11, first engineered microsphere 15, and second engineered microsphere 16 to reach the surface of the sample to be observed. The reflected light passes sequentially through the second engineered microsphere 16, first engineered microsphere 15, objective lens 11, beam splitter 10, analyzer 9, and sleeve lens 8 before reaching the camera 7. At this point, the camera 7 can acquire a high-resolution, high-magnification image of the sample to be observed formed by the double engineered microsphere lens group 13.

[0068] As an example, the stepping accuracy of the three-dimensional displacement platform on the XY axis is less than or equal to 50 nm, and the stepping accuracy on the Z axis is less than or equal to 10 nm.

[0069] refer to Figure 3 As shown, this embodiment uses the finite-difference time-domain method to calculate the magnification of the dual engineered microspheres, employing Lumerical FDTD software. This figure simulates the principle of the microsphere lens assembly. Figure 3 The object in the calculation consists of three electric dipoles spaced 300 nm apart, with a calculation wavelength of 450 nm. The images formed by the electric fields of the dipoles through different microsphere lens groups are shown in the figure. The yellow dashed box in the figure indicates the position of the image plane, and the white dashed line indicates the outline of the microsphere lens group. In all calculation models, the boundary conditions are set to perfectly matched, and the minimum grid step size is 0.5 nm. The calculation results are as follows. Figure 3 As shown. Figure 3The bottom of the microsphere lens group in (a)-(c) is an engineered microsphere with a diameter of 25 μm, a thickness of 17.5 μm, and a refractive index of 2.2. Figure 3 (a) The first engineered microsphere is a microsphere with a diameter of 60 μm and a refractive index of 1.5; Figure 3 (b) The top microsphere is a microsphere with a diameter of 70 μm and a refractive index of 1.5; Figure 3 (c) The top microsphere is an engineered microsphere with a diameter of 70 μm, a thickness of 60 μm, and a refractive index of 1.5. (Comparison) Figure 3 (a) and (b) show that as the diameter of the top microsphere gradually increases, the position of the image plane gradually moves away from the microsphere lens group, and the magnification shows an increasing trend. Figure 3 The magnifications of (a)-(c) are 8.2x, 9.6x, and 20.9x, respectively. For example... Figure 3 As shown in (c), the lens group composed of dual engineered microspheres exhibits a greater magnification, and the increase in magnification cannot be achieved by simply adjusting the diameter and thickness of the spheres to be equal, highlighting the unique advantages of the dual engineered microsphere lens group.

[0070] refer to Figure 4 As shown, this embodiment verifies the imaging performance of the dual engineered microsphere composite lens. Figure 4 (a) shows a scanning electron microscope image of the sample to be observed. The smallest feature in the array is 43 nm, which is less than the diffraction limit of visible light. Figure 4 (b) and (c) show images obtained by observing the sample under test using a 50× objective lens (NA ~0.6) and a 100× objective lens (NA ~0.8), respectively. The illumination light was an LED light source with a wavelength of 450 nm. Obviously, the sub-50 nm structure in the sample cannot be resolved under an optical microscope. Figure 4 (d) shows the imaging result of the sample under test using a dual engineered microsphere lens group. This lens group consists of barium titanate microspheres with a bottom diameter of 25 μm and a thickness of 18 μm, and borosilicate glass microspheres with a top diameter of 100 μm and a thickness of 80 μm. The image of the sample formed by the dual engineered microsphere lens group can be observed with a 20× objective lens (NA~0.4). The 43 nm structure in the sample can be clearly resolved, and the optical magnification reaches 17.8 times. Figure 4 (e) shows the imaging results of the sample under test using a single engineered microsphere lens assembly. This composite lens consists of barium titanate microspheres with a bottom diameter of 25 μm and a thickness of 18 μm, and borosilicate glass microspheres with a top diameter of 100 μm. The sample was observed using a 20× objective lens (NA~0.4), and the 43 nm structure in the sample was clearly distinguishable, with a magnification of 10.8x.

[0071] It should be noted that the imaging effect on the sample achieved by using a combination of a bottom-plane-spherical microsphere lens and a spherical microsphere lens is as described above. Figure 4 (e). The effectiveness of the dual-plane-spherical lens combination of this application on the same sample is as described above. Figure 4 (d) The advantage of this application is that it can obtain more than Figure 4 (e) Higher magnification. Higher magnification in a microscope indicates better imaging results.

[0072] Furthermore, the combination of a bottom planar-spherical microsphere lens and a spherical microsphere lens results in a limited external focal length for the top spherical microsphere lens, preventing the achievement of higher magnification. This application engineered the top spherical microsphere lens into a planar-spherical microsphere lens, effectively increasing the external focal length. It should be noted that although the bottom and top microspheres in this lens group have similar external shapes, their fundamental design purposes differ. The bottom microspheres are designed as planar-spherical to increase the angle at which light enters the lens, allowing the bottom lens to receive more information carried by the light; this requires the use of high-refractive-index materials. The top planar-spherical microsphere lens, on the other hand, requires low-refractive-index materials to achieve a longer external focal length. Therefore, this application is not equivalent to the simple cascading of existing planar-spherical microsphere lenses made of high-refractive-index materials, but rather proposes for the first time the fabrication of planar-spherical microsphere lenses using low-refractive-index materials, and verifies its effectiveness through embodiments.

[0073] like Figure 5 As shown, according to geometric optics theory, the external focal length of the perfect microsphere lens is:

[0074]

[0075] The external focal length of the engineered supermicrosphere is:

[0076]

[0077] Where t is the thickness of the engineered hemispherical sphere. The effect of thickness t on the external focal length can be further explored based on the above formula. Figure 6The relationship between the external focal length of a microsphere lens and the size of the microsphere is presented. With a refractive index of n = 1.5, the thicknesses t = 2r, t = 1.5r, and t = r are shown, corresponding to the blue, red, and orange curves in the figure, respectively. It can be seen that under these three thickness conditions, the external focal length of the microsphere monotonically increases with increasing diameter, exhibiting a continuous upward trend. This indicates that the size provides good design flexibility for the external focal length. Further comparison shows that, for the same diameter, the external focal length increases with decreasing thickness t: the external focal length of the complete microsphere (t = 2r) increases from 10 μm to 25 μm, the external focal length of the super-hemispherical structure (t = 1.5r) increases from 20 μm to 50 μm, and the external focal length of the hemispherical structure (t = r) increases from 27 μm to 67 μm. These results demonstrate that by engineered thickness control of low-refractive-index microspheres, not only can the external focal length be effectively increased, but the adjustable range of the external focal length also further increases with decreasing thickness t.

[0078] like Figure 7 As shown, to verify the effectiveness of engineered thickness control in improving the outer focal length, FDTD was used to calculate the light intensity distribution of three structures with refractive index n = 1.5 and radius r = 30 μm, and the outer focal length was extracted accordingly. Figure 7(a) shows a complete microsphere, in which the electric field on the emission side forms a focusing region behind the sphere, and the measured outer focal length is 10.69 μm; Figure 7 (b) and (c) represent engineered hemispherical microspheres with thicknesses of t = 50 μm and t = 45 μm, respectively. The focusing position on the exit side is significantly shifted outward compared to the intact microsphere, corresponding to an increase in the outer focal length to 20.33 μm and 23.67 μm, respectively. Furthermore, it can be seen that, with material parameters and radius of curvature remaining constant, as the thickness t further decreases, the focal position continues to move away from the exit plane, and the outer focal length tends to increase. The simulation results above demonstrate that thickness control introduced by engineered processing can effectively improve the outer focal length of the microsphere lens in the sense of wave optics, thereby significantly extending its usable working distance, consistent with the variation law obtained from the aforementioned analytical calculations.

[0079] The results of this embodiment demonstrate that coupling a dual engineered microsphere lens group with a microscope objective lens can achieve higher magnification and better image quality. When coupled with a 20× objective lens (NA~0.4), the resolution of this lens group even surpasses that of a 100× objective lens (NA~0.8), exhibiting not only superior imaging capabilities but also significantly reducing the dependence of high resolution on high numerical aperture objectives. This greatly reduces the manufacturing cost of high-resolution imaging systems and demonstrates broad application prospects.

[0080] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0081] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0082] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0083] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0084] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. The illustrative expressions of the above terms in this specification should not be construed as necessarily referring to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0085] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A dual engineered microsphere lens assembly, characterized in that, include: The first engineered microsphere is a planar-spherical microlens; The second engineered microsphere is a planar-spherical microlens. The second engineered microsphere is coaxially arranged with the first engineered microsphere and is located below the first engineered microsphere. The plane of the second engineered microsphere faces the sample to be observed. Furthermore, the thickness of the second engineered microsphere satisfies the following relationship: in, Indicates the thickness of the second engineered microsphere. This represents the radius of the second engineered microsphere. This represents the refractive index of the second engineered microsphere; The positions of the image planes formed by the dual engineered microsphere lenses satisfy the following relationship: in, This represents the distance from the first-order virtual image surface formed by the second engineered microsphere to the vertex on the second engineered microsphere. This represents the distance from the second-order real image plane formed by the first engineered microsphere to the vertex on the second engineered microsphere; This represents the radius of the first engineered microsphere. Indicates the refractive index of the first engineered microsphere. This indicates the thickness of the first engineered microsphere. Indicates the refractive index of the environment; The magnification of the dual engineered microsphere lens group is greater than 10x, and satisfies the following relationship: in, This indicates the magnification of the dual engineered microsphere lens assembly. This indicates the magnification of the second engineered microsphere. This indicates the magnification of the first engineered microsphere.

2. The dual engineered microsphere lens assembly as described in claim 1, characterized in that, The plane of the first engineered microsphere is oriented toward or away from the sample to be observed.

3. The dual engineered microsphere lens assembly as described in claim 1, characterized in that, The diameter of the second engineered microsphere is greater than 2 μm and less than 500 μm.

4. The dual engineered microsphere lens assembly as described in claim 3, characterized in that, The diameter of the second engineered microsphere is 25 μm.

5. The dual engineered microsphere lens assembly as described in claim 1, characterized in that, The diameter of the first engineered microsphere is 90 μm.

6. The dual engineered microsphere lens assembly as described in claim 1, characterized in that, The radius ratio of the dual-engineered microspheres satisfies the following relationship: in, Indicates the thickness of the second engineered microsphere With radius The ratio, Indicates the thickness of the first engineered microsphere With radius The ratio of .

7. An optical imaging system, characterized in that, Includes the dual-engineered microsphere lens assembly as described in any one of claims 1-6.

8. The optical imaging system as described in claim 7, characterized in that, Also includes: Lighting source; An optical microscopy system that adjusts the illumination source to reach the sample to be observed, and converts the reflected or transmitted light from the sample to obtain an imaging beam. A microsphere clamping device is used to hold the dual engineered microsphere lens group between the optical microscopy system and the sample to be observed, so as to collect the reflected or transmitted light of the sample to be observed. A three-dimensional displacement platform is used to control the relative position between the sample to be observed and the dual engineered microsphere lens group. A camera, mounted on the optical microscope system, is capable of acquiring high-resolution, high-magnification images based on an imaging beam.

9. The optical imaging system as described in claim 8, characterized in that, The stepping accuracy of the three-dimensional displacement platform on the XY axis is less than or equal to 50 nm, and the stepping accuracy on the Z axis is less than or equal to 10 nm.

Images