Optical fiber cone with free-form surface and micro-lens array

Abstract

The utility model belongs to the field of optical lenses, and particularly relates to an optical fiber cone with a free-form surface and a microlens array, which comprises a cylindrical optical fiber and a conical optical fiber which are integrally formed, and the conical optical fiber comprises a large head end with a larger size and a small head end with a smaller size. The small head end of the conical optical fiber is in arc transition connection with the end part of the cylindrical optical fiber; the conical optical fiber comprises a side surface and a top surface, and all the top surfaces are free convex curved surfaces; a micro lens array is arranged on the top surface; according to the utility model, the free-form surface is combined with the micro-lens array, so that the optical fiber light cone has an excellent light focusing effect, the image fidelity is more perfect, the definition is more distinct, and the size is smaller; the method can be applied to the sensing field, improves the sensitivity of a detector, effectively enhances the resolution, improves the imaging quality, and can greatly reduce the size of the optical fiber light cone.

Description

Technical Field

[0001] The utility model belongs to the technical field of optical lenses, and in particular relates to an optical fiber light cone with a free-form surface and a microlens array. Background Art

[0002] A fiber optic cone lens is a specialized optical component commonly used in fiber-optic communications and optical systems. Fiber optic cone lenses are thicker at one end and thinner at the other, operating based on total internal reflection. When light enters the cone from one end, it is gradually diffused or focused within the cone through multiple reflections, ultimately exiting from the other end. This magnifies or reduces the beam, achieving a focused or diffuse effect. However, conventional fiber optic cones are generally conical with flat ends. This results in significant light loss during image display, resulting in poor optical path visualization.

[0003] Therefore, it is necessary to provide an improved technical solution to the above-mentioned deficiencies in the prior art. Utility Model Content

[0004] The purpose of the utility model is to overcome the deficiencies of the prior art and provide a fiber optic light cone with a free-form surface and a microlens array, so as to solve the defects of the current fiber optic light cone, such as poor imaging quality and large size.

[0005] In order to achieve the above purpose, the present invention provides the following technical solutions:

[0006] A fiber light cone with a free-form surface and a microlens array comprises an integrally formed cylindrical optical fiber and a tapered optical fiber. The tapered optical fiber comprises a larger head end and a smaller head end, and the small head end of the tapered optical fiber is connected to the end of the cylindrical optical fiber in an arc-shaped transition. The tapered optical fiber comprises side surfaces and a top surface, and the top surface is a free-form convex surface; the top surface has a microlens array.

[0007] Furthermore, the microlens array is one of a Fresnel lens array, a convex spherical lens array, a convex aspherical lens array, or a hybrid lens array; the microlens array is a square matrix or a quincunx matrix.

[0008] Furthermore, the microlens array covers the entire top surface.

[0009] Furthermore, the microlens array is composed of a plurality of sub-lenses, the sub-lens sagittal height is 2-4 μm, the ratio of the sub-lens diameter to the sagittal height is 5-10, and the center distance between two adjacent sub-lenses is 10-40 μm.

[0010] Furthermore, the microlens array includes a convex spherical lens array located in the middle of the top surface and a convex aspheric lens array located at the edge of the top surface; the ratio of the area occupied by the convex spherical lens array to the area occupied by the convex aspheric lens array is (1-9):1; the sub-lens sagittal height in the convex spherical lens array is 2 μm, and the ratio of the diameter to the sagittal height is 5; the lens sagittal height in the convex aspheric lens array is 4 μm, and the ratio of the diameter to the sagittal height is 5.

[0011] Furthermore, the sagittal height of the tapered optical fiber is 2-4 mm.

[0012] Furthermore, the tapered optical fiber includes four side surfaces with concave curved structures, and the four side surfaces have the same size and structure.

[0013] Furthermore, the side surface is a concave spherical surface or a free concave curved surface, the side surface has a sagittal height of 2-6 mm, a ratio of diameter to sagittal height of 3-8, and a curvature radius of 2-6 times the diameter of the optical fiber cone.

[0014] Furthermore, the optical fiber light cone is made of quartz, and the total reflection angle is 41.4°.

[0015] The beneficial effects of the utility model are:

[0016] The tapered optical fiber of the utility model has less light loss, which can improve the imaging quality of the subsequent optical path; the microlens array adjusts the light, greatly improving the light efficiency while also reducing the volume of the optical fiber light cone;

[0017] The utility model adopts a free-form surface combined with a microlens array to make the fiber optic light cone have an excellent light focusing effect, more perfect image fidelity, clearer clarity, and a smaller volume; it can be applied in the field of sensing to improve the sensitivity of the detector, which not only effectively enhances the resolution and improves the imaging quality, but also greatly reduces the volume of the fiber optic light cone. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings constituting part of this application are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an improper limitation of the present invention.

[0019] Figure 1 It is a structural schematic diagram of an embodiment of the present utility model.

[0020] Figure 2 This is a structural diagram of a convex spherical lens array in an embodiment of the present invention.

[0021] Figure 3 This is a structural diagram of a microlens array according to an embodiment of the present invention when it is a convex aspheric lens array.

[0022] Figure 4 Schematic diagram of light propagation of a cylindrical optical fiber according to an embodiment of the present invention.

[0023] Figure 5 This is a schematic structural diagram of the arc-shaped transition connection between a cylindrical optical fiber and a tapered optical fiber according to an embodiment of the present utility model.

[0024] Figure 6 Schematic diagram of light propagation according to an embodiment of the present invention.

[0025] In the figure: 1-top surface, 2-side surface, 3-microlens array, 4-cylindrical optical fiber. DETAILED DESCRIPTION

[0026] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of the present invention.

[0027] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0028] like Figures 1 to 5 As shown, a fiber optic light cone with a free-form surface and a microlens array includes an integrally formed cylindrical optical fiber 4 and a tapered optical fiber, wherein the tapered optical fiber includes a larger head end and a smaller head end, and the small head end of the tapered optical fiber is connected to the end of the cylindrical optical fiber 4 in an arc-shaped transition; the tapered optical fiber includes a side surface 2 and a top surface 1, and all top surfaces 1 are free convex surfaces, which are conducive to converging the light inside the optical fiber; a microlens array 3 is provided on the top surface 1; the tapered optical fiber of the utility model is made of quartz material, and the total reflection angle is 41.4°. The light inside the fiber optic light cone is totally reflected, and the loss of light is small, which can improve the imaging quality of the subsequent optical path; the microlens array 3 can adjust the light and greatly improve the light efficiency while reducing the volume of the fiber optic light cone.

[0029] like Figures 1 to 3 As shown, the microlens array 3 is one of a Fresnel lens array, a convex spherical lens array, a convex aspheric lens array, or a hybrid lens array; the microlens array 3 is a square matrix or a quincunx matrix. The outer contour of the microlens array 3 is preferably circular; the microlens array 3 is disposed partially on the top surface 1 or covers the entire top surface 1. The best effect is achieved when the microlens array 3 covers the entire top surface 1.

[0030] like Figures 1 to 3As shown, the tapered optical fiber has a sagittal height of 2-4 mm, and there are no requirements for the diameter of the tapered optical fiber. The microlens array 3 is composed of several sub-lenses, each with a sagittal height of 2-4 μm. The ratio of the diameter to the sagittal height of the sub-lenses is 5-10. The center-to-center distance between two adjacent sub-lenses is 10-40 μm. In the optimal embodiment, the microlens array 3 is a hybrid lens array composed of a convex spherical lens array and an annular convex aspheric lens array. The convex spherical lens array is located in the center, with a sub-lens sagittal height of 2 μm and a diameter-to-sagittal ratio of 5. The convex aspheric lens array is located at the edge, with a sub-lens sagittal height of 4 μm and a diameter-to-sagittal ratio of 5. The ratio of the area occupied by the convex spherical lens array to the area occupied by the convex aspheric lens array is (1-9):1.

[0031] like Figure 1 、 Figure 5 、 Figure 6 As shown, the tapered optical fiber includes four concavely curved side surfaces 2, each of which is identical in size and structure, facilitating total internal reflection of light within the optical fiber. Specifically, the side surfaces 2 are concave spherical or free-form concave surfaces, with a rise of 2-6 mm, a diameter-to-rise ratio of 3-8, and a radius of curvature 2-6 times the diameter of the optical fiber cone.

[0032] like Figure 4 、 Figure 5 As shown in Figure 2, when light propagates in an optical fiber at an input angle of 7.27°, Figure 4 In the cylindrical profile of the cylindrical optical fiber 4, both parallel lights pass through the cylindrical optical fiber 4 (made of quartz) and the refraction angle is 11.31°; Figure 4 It can also be seen as a schematic diagram of the optical path of an ordinary cylindrical quartz optical fiber; Figure 5 In the figure, the light propagation in the cylindrical optical fiber 4 of the two parallel lights is as follows: Figure 4 Exactly the same, but the incident angle of the light on the left side changes to 41.4° because the side 2 of the tapered optical fiber has a concave profile. 41.4° is the total reflection angle of this optical fiber light cone, so the light undergoes total reflection.

[0033] Figure 6 The side surface 2 of the tapered optical fiber is a concave surface, and the top surface 1 adopts a convex spherical lens array. The array has a sub-lens in the center and a circle of sub-lenses arranged in a ring shape on the edge. Figure 6 The local magnified images of the fiber light cones A, B, and C and the optical path diagram are also given. Figure 5 When the incident angle Figure 6 When the light in the fiber optic cone is emitted, it can be refracted to emit parallel light. Similarly, if parallel light is emitted from the top surface 1 of the fiber optic cone, it is clear that the top of the fiber optic cone of this structure has a significant light converging effect.

[0034] The following describes the preparation process of the fiber light cone with a free-form surface and a microlens array of the present invention, which includes the following steps:

[0035] Step 1: Take a quartz optical fiber raw material with a conical end, and use a mechanical micro-cutting method to process the four sides of the optical fiber raw material into concave surfaces;

[0036] Step 2: Use polyurethane, non-woven fabric and grinding liquid to grind and polish the four sides respectively;

[0037] Step 3: using a photolithography method to prepare a convex top surface structure (the top surface includes a microstructure array) on the surface of the photoresist, and the photoresist is preferably AZ4562 photoresist;

[0038] Step 4: Using a secondary transfer method, transfer the convex top surface structure (the top surface includes the microstructure array) prepared by the photoresist to the top of the tapered optical fiber;

[0039] Step 5: Use plasma etching to etch the top of the optical fiber cone into a free convex surface with a microlens array.

[0040] The utility model sets the top surface of the fiber optic light cone as a free-form surface combined with a microlens array, so that the fiber optic light cone has an excellent light focusing effect, the image fidelity is more perfect, and the clarity is clearer, which not only effectively improves the imaging quality, but also greatly reduces the volume of the fiber optic light cone.

[0041] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are within the scope of protection of the pending claims of the present invention.

Claims

1. A fiber light taper having a free-form surface and a microlens array, characterized in that: The invention comprises an integrally formed cylindrical optical fiber and a tapered optical fiber, wherein the tapered optical fiber comprises a larger head end and a smaller head end, and the small head end of the tapered optical fiber is connected to the end of the cylindrical optical fiber in an arc-shaped transition; the tapered optical fiber comprises side surfaces and a top surface, and the top surface is a free convex surface; and a microlens array is provided on the top surface.

2. The fiber light taper with a free-form surface and a microlens array according to claim 1, characterized in that: The microlens array is one of a Fresnel lens array, a convex spherical lens array, a convex aspherical lens array, or a hybrid lens array.

3. The fiber taper with a free-form surface and a microlens array according to claim 1, wherein: The microlens array is a square matrix or a quincunx matrix.

4. The fiber taper with a free-form surface and a microlens array according to claim 1, wherein: The microlens array covers the entire top surface.

5. The optical fiber light taper with a free-form surface and a microlens array according to claim 1, characterized in that: The microlens array is composed of a number of sub-lenses, the sub-lens sagittal height is 2-4 μm, the ratio of the sub-lens diameter to the sagittal height is 5-10, and the center distance between two adjacent sub-lenses is 10-40 μm.

6. The optical fiber light taper having a free-form surface and a microlens array according to claim 5, characterized in that: The microlens array includes a convex spherical lens array located in the middle of the top surface and a convex aspheric lens array located at the edge of the top surface, and the ratio of the area occupied by the convex spherical lens array to the area occupied by the convex aspheric lens array is (1-9):1; the sub-lens sagittal height in the convex spherical lens array is 2μm, and the ratio of diameter to sagittal height is 5; the lens sagittal height in the convex aspheric lens array is 4μm, and the ratio of diameter to sagittal height is 5.

7. The fiber light taper with a free-form surface and a microlens array according to claim 1, characterized in that: The sagittal height of the tapered optical fiber is 2-4 mm.

8. The fiber taper with a free-form surface and a microlens array according to claim 1, wherein: The tapered optical fiber includes four side surfaces with concave curved structures, and the four side surfaces have the same size and structure.

9. The optical fiber light taper with a free-form surface and a microlens array according to claim 8, characterized in that: The side surface is a concave spherical surface or a free concave curved surface, the side surface has a sagittal height of 2-6 mm, a ratio of diameter to sagittal height of 3-8, and a curvature radius of 2-6 times the diameter of the optical fiber cone.

10. The fiber taper with a free-form surface and a microlens array according to claim 1, characterized in that: The fiber optic light cone is made of quartz, and the total reflection angle is 41.4°.

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