Preparation method of hemispherical long-focus lens and hemispherical long-focus lens
By fabricating a hemispherical long focal length lens, the imaging difficulties and contamination problems caused by the contact between the microstructure lens and the sample were solved, realizing super-resolution imaging and wide field of view imaging, and improving the performance of the optical microscope.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SHENZHEN INST OF ADVANCED TECH CHINESE ACAD OF SCI
- Filing Date
- 2023-04-04
- Publication Date
- 2026-07-14
Smart Images
Figure CN116430489B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of optical lens fabrication technology, and in particular to a method for fabricating a hemispherical telephoto lens and the hemispherical telephoto lens itself. Background Technology
[0002] Optical microscopes are the key to unlocking the microscopic world and are widely used in biomedical, materials, chemical, and physical research. However, limited by the diffraction limit, their resolution is difficult to exceed half the wavelength (200-300 nm). With advancements in technology, various techniques now exist to overcome the diffraction limit and observe the fine structures within samples. Microstructure lens-assisted super-resolution imaging is one simple and readily available method. When a microstructure lens is irradiated by incident light, a photon nanojet with an intensity much higher than the incident light and a full width at half maximum (FWHM) less than half the wavelength is formed on its back, enabling imaging of fine structures smaller than the diffraction limit. Currently, microstructure lenses used in this field (such as microspheres and micropillars) have short focal lengths and small fields of view, making them prone to contact with the sample during imaging, causing difficulties in scanning and potentially contaminating or damaging the sample. To address this problem, the inventors designed a movable, hemispherical long-focal-length microlens that assists conventional optical microscopes in achieving super-resolution imaging of samples without direct contact between the lens and the sample.
[0003] Korean Patent KR1020010011213A discloses a method and apparatus for manufacturing a miniature solid immersion lens, used for recording and replaying optical information using the lens; Chinese Patent CN202210356452.8 discloses a method for preparing a composite structure micro-bottle lens and the composite structure micro-bottle lens. However, the microstructure lenses currently used in this field have short focal lengths and small fields of view, and are prone to contact with the sample during imaging, causing difficulties in scanning imaging and contamination or damage to the sample. Summary of the Invention
[0004] Therefore, it is necessary to provide a method for preparing a hemispherical telephoto lens and a hemispherical telephoto lens that achieves super-resolution imaging of the sample under test without the lens contacting the sample, in order to address the deficiencies in the existing technology.
[0005] To solve the above problems, this application adopts the following technical solution:
[0006] One of the objectives of this application is to provide a method for manufacturing a hemispherical telephoto lens, comprising the following steps:
[0007] Provide single-cone optical fiber;
[0008] UV photoresist is applied to the tapered region of the tapered optical fiber;
[0009] The ultraviolet photopolymer forms tiny spindle-shaped droplets;
[0010] Provide a thin film;
[0011] The tiny spindle-shaped droplets are transferred to the film, and the tiny spindle-shaped droplets form a hemispherical shape.
[0012] The hemispherical micro-spindle-shaped droplets are irradiated with ultraviolet light and solidified to obtain the hemispherical telephoto lens.
[0013] In some embodiments, the step of providing a tapered optical fiber specifically includes the following steps:
[0014] One end of the fiber with the coating stripped is fixed to the optical connector, and the other end is fixed to the displacement stage;
[0015] The optical fiber is heated, and the displacement stage is rotated to stretch the optical fiber, forming a tapered optical fiber.
[0016] The optical fiber is stretched further using the displacement stage until it breaks.
[0017] In some embodiments, the step of attaching UV adhesive to the tapered region of the tapered optical fiber specifically includes the following steps:
[0018] The conical optical fiber is placed vertically, and ultraviolet adhesive is dropped into the conical region of the fiber. The adhesive slides down due to its own gravity, leaving some adhesive adhering to the conical region.
[0019] In some embodiments, the step of the ultraviolet adhesive forming tiny spindle-shaped droplets specifically includes the following steps: the ultraviolet adhesive attached to the conical region forms tiny spindle-shaped droplets under the action of solid-liquid interfacial tension.
[0020] In some embodiments, the step of providing a thin film specifically includes the following steps:
[0021] Photoresist is coated onto a substrate and cured to form a photoresist layer;
[0022] A curable polymer is coated onto the photoresist layer and then cured to form a thin film layer.
[0023] The substrate is immersed in an organic solvent to dissolve the photoresist layer, and the thin film layer floats on the surface of the organic solvent.
[0024] The thin film is obtained by removing the thin film layer.
[0025] In some embodiments, the step of coating a substrate with photoresist and curing it to form a photoresist layer includes a glass substrate.
[0026] In some embodiments, the curable polymer comprises polydimethylsiloxane in the step of coating the photoresist layer with a curable polymer and curing it to form a thin film layer.
[0027] In some embodiments, the step of transferring the micro-spindle-shaped droplets to the film and forming the micro-spindle-shaped droplets into a hemispherical shape specifically includes the following steps:
[0028] A tapered optical fiber containing the tiny spindle-shaped droplets is placed horizontally, and the tiny spindle-shaped droplets are transferred to the thin film. The tiny spindle-shaped droplets naturally form a hemispherical shape on the surface of the thin film through superhydrophobic effect and interfacial interaction.
[0029] The second objective of this application is to provide a hemispherical telephoto lens, which is prepared by the aforementioned method for preparing a hemispherical telephoto lens.
[0030] The present application adopts the above technical solution, and its beneficial effects are as follows:
[0031] The hemispherical telephoto lens and its fabrication method provided in this application involve attaching ultraviolet photoresist to the tapered region of a tapered optical fiber. The ultraviolet photoresist forms tiny spindle-shaped droplets, which are then transferred to a thin film, forming a hemispherical shape. These hemispherical droplets are then irradiated with ultraviolet light and cured to obtain the hemispherical telephoto lens. The hemispherical telephoto lens and its fabrication method provided in this application utilize a movable thin film to support the movement of the hemispherical lens, thus leveraging the telephoto advantage of the hemispherical lens and providing the potential for wide-field imaging through scanning. Furthermore, the above fabrication method is simple, the system is easy to implement, and it can be used to fabricate a movable telephoto hemispherical lens at low cost, improving the performance of conventional optical microscopes. Attached Figure Description
[0032] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments of this application or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0033] Figure 1 A schematic diagram illustrating the fabrication principle of the tapered optical fiber provided in Example 1;
[0034] Figure 2 A flowchart illustrating the fabrication process of the tapered optical fiber provided in Example 1;
[0035] Figure 3 This is a schematic diagram illustrating the fabrication principle of the ultrathin, movable, transparent film provided in Example 2.
[0036] Figure 4 The flowchart shows the preparation process of the thin film provided in Example 2.
[0037] Figure 5 This is a diagram illustrating the fabrication process of the hemispherical lens provided in Example 3.
[0038] Figure 6 This is a flowchart illustrating the steps of a method for preparing a hemispherical telephoto lens as provided in Embodiment 3.
[0039] Figure 7 The left and right views are front and side views of the hemispherical telephoto lens provided in this embodiment.
[0040] Figure 8 This is a schematic diagram showing the comparison of the focal lengths of the microsphere lens (left) and the hemispherical lens (right) using finite element simulation software, as provided in this embodiment.
[0041] Figure 9 The focal length of the lens is calculated using simulation software when there is a thin film of a certain thickness below the hemispherical lens, as provided in this embodiment.
[0042] Figure 10 The image provided in this embodiment is a scanning electron microscope image of a DVD disc (left) and a microscope image of DVD disc stripes observed with a movable hemispherical long focal length microlens (right). Detailed Implementation
[0043] The embodiments of this application are described in detail below. Examples of these embodiments are shown 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 this application, and should not be construed as limiting this application.
[0044] In the description of this application, it should be understood that the terms "upper", "lower", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application 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, and therefore should not be construed as a limitation of this application.
[0045] 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 application, "multiple" means two or more, unless otherwise explicitly specified.
[0046] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments.
[0047] Example 1
[0048] Please see Figure 1 This is a schematic diagram illustrating the fabrication principle of the tapered optical fiber provided in Embodiment 1. Figure 1 It includes an optical fiber coating layer 1, a bare optical fiber 2, a fixing screw 3, an optical support 4, a displacement stage 5, a butane torch 6, a stretched tapered optical fiber 7, and a broken tapered optical fiber 8.
[0049] Please see Figure 2 This is a flowchart of the fabrication process of the tapered optical fiber provided in this embodiment, including steps S110 to S130 below. The following is in conjunction with... Figure 1 Provide a detailed explanation of how each step is implemented.
[0050] Step S110: Fix one end of the fiber with the coating stripped to the optical connector and the other end to the displacement stage.
[0051] In this embodiment, the optical fiber can be glass fiber, plastic fiber, special stripped fiber, etc. The screws used to fix the optical fiber in this embodiment can also be replaced by other clamps with holding functions. The device used to stretch the optical fiber is not limited to optical supports or displacement stages; other systems or devices with stretching functions are also acceptable.
[0052] Step S120: Heat the optical fiber and rotate the displacement stage to stretch the optical fiber to form a tapered optical fiber.
[0053] In this embodiment, a butane torch can be used to heat the optical fiber, or other devices with heating functions can be used instead, such as an arc lighter, an alcohol lamp, or a carbon dioxide laser.
[0054] Step S130: Continue to stretch the optical fiber using the displacement stage until the optical fiber breaks.
[0055] It is understood that in this embodiment, the optical fiber is broken by stretching it with a rotary displacement stage. In practice, the breaking of the tapered optical fiber can also be accomplished by an optical fiber cleaver or scissors.
[0056] The fabrication method of the tapered optical fiber provided in Embodiment 1 of this application is simple and easy to implement.
[0057] Example 2
[0058] Please see Figure 3This is a schematic diagram of the preparation principle of the ultrathin movable transparent film provided in Embodiment 2 of this application, wherein the glass plate 9, the spin coater 10, the syringe 11, the photoresist droplet 12, the photoresist layer 13, the ultraviolet lamp 14, the polydimethylsiloxane 15, the thin film layer 16, the oven 17, the organic solvent 18, the container 19, and the perforated hard metal sheet 20.
[0059] Please see Figure 4 The above is a flowchart of the thin film preparation process provided in Embodiment 2 of this application, specifically including the following steps S210 to S240, which are described below in conjunction with... Figure 3 Provide a detailed explanation of how each step is implemented.
[0060] Step S210: Coat the substrate with photoresist and cure it to form a photoresist layer.
[0061] In this embodiment, the substrate includes a glass sheet substrate.
[0062] Please combine Figure 3 In this embodiment, the glass substrate is placed in a spin coater, and photoresist is applied and spin-coated onto the substrate using a syringe. The glass substrate is then placed under an ultraviolet lamp to photocur the photoresist.
[0063] It is understandable that the photoresist spin-coated on the glass slide can be replaced with other liquid spin-coated materials that are soluble in organic solvents.
[0064] Step S220: Coat the photoresist layer with a curable polymer and cure it to form a thin film layer.
[0065] In this embodiment, the curable polymer comprises dimethylsiloxane. It is understood that polydimethylsiloxane can be replaced with other liquid spin-coated materials that are insoluble in organic solvents.
[0066] Specifically, the glass slide is placed on a spin coater, and curable polymers such as polydimethylsiloxane are dripped or spin-coated upwards to form a thin film layer. The glass slide is then placed in an oven to heat-cur the polydimethylsiloxane thin film layer.
[0067] Step S230: Immerse the substrate in an organic solvent to dissolve the photoresist layer, and the thin film layer floats on the surface of the organic solvent.
[0068] It is understandable that immersing the glass sheet in an organic solvent dissolves the photoresist layer between the glass sheet substrate and the thin film layer, after which the thin film layer floats on the surface of the organic solvent due to its own buoyancy.
[0069] Step S240: Remove the thin film layer to obtain the thin film.
[0070] In this embodiment, the film is removed using a metal sheet with a central hole. It is understood that the metal sheet can be replaced with other machinable, rigid, thin materials, such as glass.
[0071] The thin film preparation method provided in Embodiment 2 of this application is simple and easy to implement.
[0072] Example 3
[0073] Please see Figure 5 The diagram shows the fabrication process of the hemispherical lens provided in this embodiment 3, wherein: UV adhesive 12, UV adhesive residue 21, spindle-shaped droplet 22, hemispherical droplet 24, and hemispherical long focal microlens 25 after UV curing.
[0074] Please see Figure 6 The flowchart below shows the steps of a method for preparing a hemispherical telephoto lens according to Embodiment 3, including steps S310 to S360. The following is a combination of steps S310 to S360. Figure 5 Provide a detailed explanation of how each step is implemented.
[0075] Step S310: Provide a tapered optical fiber.
[0076] For details on its implementation, please refer to Example 1, which will not be repeated here.
[0077] Step S320: Apply UV adhesive to the tapered region of the tapered optical fiber.
[0078] In some embodiments, the step of attaching UV adhesive to the conical region of the conical optical fiber specifically includes the following steps: placing the conical optical fiber vertically, dripping UV adhesive into the conical region of the conical optical fiber, and the UV adhesive sliding down due to its own gravity, with a portion of the UV adhesive adhering to the conical region.
[0079] Step S330: The ultraviolet adhesive forms tiny spindle-shaped droplets.
[0080] In some embodiments, the step of the ultraviolet adhesive forming tiny spindle-shaped droplets specifically includes the following steps: the ultraviolet adhesive attached to the conical region forms tiny spindle-shaped droplets under the action of solid-liquid interfacial tension.
[0081] Step S340: Provide a thin film.
[0082] For details on its implementation, please refer to Example 2, which will not be repeated here.
[0083] Step S350: The tiny spindle-shaped droplets are transferred to the film, and the tiny spindle-shaped droplets form a hemispherical shape.
[0084] In some embodiments, the step of transferring the micro-spindle-shaped droplets to the thin film and forming a hemispherical shape from the micro-spindle-shaped droplets specifically includes the following steps: placing the tapered optical fiber containing the micro-spindle-shaped droplets horizontally and transferring the micro-spindle-shaped droplets to the thin film, wherein the micro-spindle-shaped droplets naturally form a hemispherical shape on the thin film through superhydrophobic effects and interfacial interactions.
[0085] Step S360: Irradiate the hemispherical micro-spindle-shaped droplets under ultraviolet light, and after solidification, obtain the hemispherical telephoto lens.
[0086] The hemispherical telephoto lens and its fabrication method provided in Embodiment 3 of this application utilize a movable thin film to support the movement of the hemispherical lens, which not only leverages the telephoto advantage of the hemispherical lens but also provides the potential for wide-field imaging through scanning. Furthermore, the above-mentioned fabrication method is simple, the system is easy to implement, and it can be easily operated and realized, enabling the fabrication of a movable telephoto hemispherical lens at low cost, thereby improving the performance of conventional optical microscopes.
[0087] Please see Figure 7 The images show a front view (left) and a side view (right) of the hemispherical telephoto lens provided in Embodiment 3 of this application.
[0088] Please see Figure 8 This is a schematic diagram comparing the focal lengths of a microsphere lens (left) and a hemispherical lens (right) using finite element simulation software in an embodiment of this application. Except for the shape, all other settings are the same. The simulation results show that the focal length of the microsphere lens with a radius of 30μm is 9.4μm, while the focal length of the hemispherical lens with the same radius is about 30μm.
[0089] Please see Figure 9 To account for the influence of film thickness on the focal length of the hemispherical lens in this embodiment, simulation software was used to calculate the focal length of the lens when there is a film of a certain thickness below the hemispherical lens. When the film thickness is 10 μm, the focal length of the hemispherical lens with a radius of 30 μm is still nearly 25 μm, which is still longer than the focal length of the microsphere lens with a radius of 30 μm. Therefore, the simulation results show that the hemispherical lens fabricated on the film still has a relatively long focal length.
[0090] Please see Figure 10 The images shown are a scanning electron microscope (SEM) image of a DVD disc (left) and a microscope (right) using a movable hemispherical telephoto lens to observe the stripes on the DVD disc. The hemispherical radius is approximately 8 μm, and the minimum feature width of the DVD disc is 340 nm.
[0091] It is understood that the technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0092] The above are merely preferred embodiments of this application, and only specifically describe the technical principles of this application. These descriptions are only for explaining the principles of this application and should not be construed as limiting the scope of protection of this application in any way. Based on this explanation, any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application, as well as other specific embodiments of this application that can be conceived by those skilled in the art without creative effort, should be included within the scope of protection of this application.
Claims
1. A method for manufacturing a hemispherical telephoto lens, characterized in that, Includes the following steps: Provide single-cone optical fiber; UV photoresist is applied to the tapered region of the tapered optical fiber; The ultraviolet photopolymer forms tiny spindle-shaped droplets; Provide a thin film; The tiny spindle-shaped droplets are moved to the film, and the tiny spindle-shaped droplets form a hemispherical shape. The hemispherical micro-spindle-shaped droplets are irradiated with ultraviolet light and solidified to obtain the hemispherical telephoto lens; The step of providing a thin film specifically includes the following steps: Photoresist is coated onto a substrate and cured to form a photoresist layer; A curable polymer is coated onto the photoresist layer and then cured to form a thin film layer. The substrate is immersed in an organic solvent to dissolve the photoresist layer, and the thin film layer floats on the surface of the organic solvent. The thin film is obtained by removing the thin film layer.
2. The method for preparing a hemispherical telephoto lens as described in claim 1, characterized in that, The steps for providing a single-cone optical fiber specifically include the following: One end of the fiber with the coating stripped is fixed to the optical connector, and the other end is fixed to the displacement stage; The optical fiber is heated, and the displacement stage is rotated to stretch the optical fiber, forming a tapered optical fiber. The optical fiber is stretched further using the displacement stage until it breaks.
3. The method for preparing a hemispherical telephoto lens as described in claim 1, characterized in that, The step of attaching UV adhesive to the tapered region of the tapered optical fiber specifically includes the following steps: The conical optical fiber is placed vertically, and ultraviolet adhesive is dropped into the conical region of the fiber. The adhesive slides down due to its own gravity, leaving some adhesive adhering to the conical region.
4. The method for preparing a hemispherical telephoto lens as described in claim 1, characterized in that, The step of forming tiny spindle-shaped droplets with ultraviolet light adhesive specifically includes the following steps: the ultraviolet light adhesive attached to the conical region forms tiny spindle-shaped droplets under the action of solid-liquid interfacial tension.
5. The method for preparing a hemispherical telephoto lens as described in claim 1, characterized in that, In the step of coating a photoresist onto a substrate and curing it to form a photoresist layer, the substrate includes a glass substrate.
6. The method for preparing a hemispherical telephoto lens as described in claim 1, characterized in that, In the step of coating a curable polymer onto the photoresist layer and curing it to form a thin film layer, the curable polymer includes polydimethylsiloxane.
7. The method for preparing a hemispherical telephoto lens as described in claim 1, characterized in that, The step of transferring the micro-spindle-shaped droplets to the thin film and forming the micro-spindle-shaped droplets into a hemispherical shape specifically includes the following steps: A tapered optical fiber containing the tiny spindle-shaped droplets is placed horizontally, and the tiny spindle-shaped droplets are transferred to the thin film. The tiny spindle-shaped droplets naturally form a hemispherical shape on the surface of the thin film through superhydrophobic effect and interfacial interaction.
8. A hemispherical telephoto lens, characterized in that, The hemispherical telephoto lens is prepared by the method described in any one of claims 1 to 7.