Method for zoning and beam uniformity adjustment of a fiber bundle

Abstract

The application discloses a method for sub-region weaving and beam uniformity adjustment of an optical fiber bundle. For a branch optical fiber bundle, sub-regions of a light source (or an incident end cross section) can be divided and a plurality of micro-regions can be further divided in the sub-regions according to the beam quality of the used light source, the diameter of the optical fiber, the number of branches and the required homogenization degree. Each micro-region is composed of a small bundle of optical fibers. The size and number of the micro-regions are adjusted to realize the purpose of adjustable beam uniformity. The application is suitable for one-to-many and many-to-many optical fiber bundle manufacturing and has wide applicability and technical value. The method not only improves the beam uniformity of the optical fiber bundle, but also enhances the mechanical strength and stability of the optical fiber bundle, and meets the requirements of different fields on the beam uniformity of the optical fiber bundle.

Description

Technical Field

[0001] This invention relates to the technical field of optical fiber bundles, and in particular to a method for partitioned braiding of optical fiber bundles and adjustable beam uniformity. Background Technology

[0002] Fiber optic bundles are products made by bundling multiple fiber filaments together. They can be used for energy transmission and image transmission, and have numerous application examples and promising development prospects in fields such as laser medicine, energy detection, ultraviolet lithography, and quality inspection.

[0003] The light source to be transmitted through an optical fiber bundle is usually a non-homogeneous source, and the desired result after transmission is a homogenized beam. Currently, in the fabrication of branched optical fiber bundles, to compensate for the insufficient uniformity of the light source itself and improve the uniformity of the light field distribution at the output end, the traditional approach is to randomly braid the optical fibers. This involves scattering and mixing the fiber filaments at one end of the bundle, disrupting the spatial arrangement of the fibers so that the positional relationship between the input and output fibers is not one-to-one, thus achieving beam homogenization. However, this approach has certain limitations: Firstly, the uncertainty of random braiding leads to large variations in beam quality, making it difficult to provide feedback and iterative optimization, and thus easily resulting in insufficient fiber homogenization. If the uniformity of the output light field cannot be guaranteed, it is often necessary to add an optical homogenizing device before the input end or after the output end to homogenize and shape the beam, increasing system complexity. Secondly, random braiding can also easily lead to unnecessary over-scattering and mixing, resulting in a huge workload and potentially increasing the fiber breakage rate and reducing efficiency. When applied to product production lines, the lack of a quantifiable and effective means to control the uniformity of the emitted light field of fiber bundles can significantly reduce product yield and increase production costs. Summary of the Invention

[0004] To overcome the shortcomings of the prior art, the present invention aims to provide a method for partitioned weaving and adjustable beam uniformity of fiber bundles. For single-split or multi-split multi-branch fiber bundles, the present invention can perform partitioned weaving and micro-area construction based on the beam quality of the incident light source and the desired homogenization effect. First, the optical field uniformity of the micro-areas is achieved. Then, numerous micro-areas are arranged and combined into the desired fiber bundle end-face shape, improving the uniformity of the optical field distribution across the entire output end-face. This compensates for the insufficient illuminance uniformity caused by unarranged, disordered, or randomly scattered fiber filaments when the light source beam quality is poor. Furthermore, uniformity can be adjusted by modifying the number and size of the micro-areas. This can meet the uniformity requirements of high-power devices. The method proposed in this invention can quantitatively determine the specific weaving process based on the light source beam quality and the required homogenization effect of the output optical field.

[0005] The technical solution of this invention is as follows:

[0006] A method for partitioned braiding of an optical fiber bundle and adjustable beam uniformity, characterized in that the method includes the following steps:

[0007] 1) Provide optical fiber, including core and cladding. The core of the optical fiber is made of glass or other materials, and the cladding is made of glass or other materials with a refractive index lower than that of the core material. The optical fiber coating is made of a coloring material.

[0008] 2) Based on the total amount of fiber filaments and the number of branches required for the fiber bundle, cut the fiber into equal portions according to the number of branches for later use, and then braid and bundle them together.

[0009] 3) First, based on the beam quality of the light source, the light source (or the incident end cross-section) is divided into n equal-area sub-regions S, which are numbered 1, 2, 3, ... n. The optical fibers constituting each sub-region are distinguished by different paint colors.

[0010] 4) Each sub-region is further subdivided into M micro-regions. M is a multiple of N, M is greater than or equal to N, and N is the number of branches. Within the same sub-region, the difference between the maximum and minimum power is ΔP, expressed as a percentage. The size of the micro-region depends on the optical power difference between the sub-regions. The larger ΔP is, the smaller the corresponding micro-region needs to be, and the smaller ΔP is, the larger the corresponding micro-region needs to be.

[0011] The size of the micro-region is determined by the beam quality of the light source used, the diameter of the optical fiber, and the required degree of homogenization. To facilitate the construction of the micro-region, it is first necessary to define the homogenization effect: the power ratio (i.e., the power ratio described in the homogenization effect) φp of any two small regions of equal area on the output end face of the fiber bundle. The closer this value is to 1, the better the homogenization effect.

[0012] The specific size of the micro-region depends on the desired homogenization effect φp and ΔP.

[0013] Subsequently, based on the zoning plan of the light source (or the cross-section of the incident end), n sub-zones of equal area are divided at the branch end. Each region is numbered 1, 2, 3, ..., n, corresponding to the n sub-regions of the incident end. Sub-zone number 1 corresponds to sub-region 1 of the incident end, and sub-zone number n corresponds to sub-region n of the incident end. Multiple micro-regions from the corresponding sub-region can be arranged within each sub-zone.

[0014] a) In the above-mentioned sub-regions S of equal area, if there is a drastic change in energy in a single region, the micro-region taken in that region needs to be further reduced.

[0015] b) The several equal-area sub-regions S do not need to have the same shape;

[0016] c) The smaller the diameter of the optical fiber, the smaller the micro-area that can be created;

[0017] 5) The aforementioned micro-regions can be fixed by bundling multiple optical fibers. The fiber end faces of the micro-regions can be constructed into circular, wavy, rectangular, polygonal, or other shapes as needed. To facilitate the arrangement and assembly of micro-regions at the branch end, the shape of the micro-regions generally depends on the shape of the branch end. If the branch is circular, the micro-regions are hexagonal sub-bundles (the number of optical fibers in the micro-regions is 7, 19, 37, 61...); if the branch is square, the micro-regions are also square. If the goal of high transmittance of the fiber bundle is to achieve the target of hexagonal close packing of the end face fibers, then the micro-regions should preferably be hexagonal sub-bundles.

[0018] 6) At one end of the fiber bundle, the fibers are unraveled and braided. The length of the braided area is generally 400-500mm, but the braiding length can be increased as needed.

[0019] 7) Align the heads of the light-transmitting micro-areas constructed to the above size and shape and place them in the mold of the light-transmitting area of ​​the matching fiber bundle output end, arrange them according to the sub-area number, and bundle them together to form the entire end face.

[0020] The braiding operation is characterized by breaking down and mixing the numerous sub-bundles of optical fibers that constitute the light-transmitting micro-region.

[0021] The mold material can be a polymer material or a metal material; alternatively, a mold can be not used, and the mold can be manually shaped to the desired end face shape.

[0022] This invention is applicable to the fabrication of one-to-many and many-to-many fiber bundles.

[0023] The manufacturing process of this invention involves first manufacturing the light input end, and then manufacturing the light output end.

[0024] Compared with the prior art, the technical effects of the present invention are as follows:

[0025] This invention provides a method for partitioned braiding of optical fiber bundles and adjustable beam uniformity. In the fabrication of branched optical fiber bundles, it innovatively proposes dividing the fiber incident end face into sub-regions and micro-regions based on the beam quality of the light source. This involves braiding the micro-region sub-bundles and arranging them in a numbered manner at the branch end. This method is simple, convenient, and easy to implement. Compared to traditional methods, it further optimizes the uniformity of the optical field distribution at the branch end of the optical fiber bundle, and the uniformity of the optical field distribution can be adjusted by changing the size and number of micro-regions. Based on the beam quality of the incident light source, the diameter of the optical fiber, and the required degree of uniformity, the light source (or the incident end cross-section) is divided into sub-regions and micro-regions. The optical fiber is then braided at one end of the bundle, and the micro-regions are arranged according to their corresponding sub-region numbers on the light exit end face to form the desired end face shape. Adjustment of the beam uniformity can be achieved by controlling the size and number of micro-regions. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the constructed hexagonal light-transmitting micro-area end face.

[0028] Figure 2 This is a schematic diagram of the braiding operation framework for a one-to-three fiber bundle in the embodiment.

[0029] Figure 3 This is a schematic diagram of the light spot energy distribution of the light source used.

[0030] Figure 4 This is a schematic diagram of the sub-regions divided in the embodiment.

[0031] Figure 5 This is a schematic diagram of branch terminal partitioning.

[0032] Figure 6 This is a schematic diagram of the bundling and braiding process of a three-in-one fiber bundle in the embodiment.

[0033] Figure 7 This is a schematic diagram of the incident end face of the optical fiber bundle.

[0034] In all the accompanying drawings, different elements and structures are indicated by reference numerals, wherein:

[0035] 1-Single optical fiber constituting a micro-region

[0036] 2-Input end of a 1-to-3 fiber optic bundle

[0037] 3-Incident end fixing clamp

[0038] 4-Inner diameter shrinkage ring

[0039] 5-Branch of a 1-to-3 fiber optic bundle

[0040] 6-Fiber Wire

[0041] 7-Constructed light-transmitting micro-region sub-beam Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0043] This invention provides a method for partitioned braiding and adjustable beam uniformity of a 1-to-3 fiber bundle, wherein both the input and output ends of the fiber bundle are circular. The method includes the following steps:

[0044] 1) Take a batch of 10km long optical fibers. The core material is pure quartz, the cladding material is fluorine-doped quartz, the bare fiber outer diameter is 190μm, and the coating uses a coloring material.

[0045] 2) Cut these optical fibers to a length of 1500±100mm, yielding approximately 6666 fibers. One end of each fiber is fixed into a circular incident end face shape using a mold, as shown below. Figure 7 As shown

[0046] 3) Place the entire fiber bundle vertically in a position such as... Figure 2 On the weaving operation frame shown, the incident end is fixed with a fixing clamp.

[0047] 4) According to such Figure 3 The incident light spot energy distribution shown divides the incident end face of the fiber bundle into eight equal-area sub-regions. Each sub-region is shaped like a central circle surrounded by seven equally sized annexes, numbered 1, 2, 3, ... 8. A schematic diagram of the sub-region division is shown below. Figure 4 As shown. Within the same sub-region, the difference between the maximum and minimum power is ΔP, expressed as a percentage. A larger ΔP requires a smaller corresponding micro-region, and a smaller ΔP requires a larger corresponding micro-region. The fiber coating color is different for each sub-region to distinguish them.

[0048] 5) Before the formal micro-area construction and weaving, the desired homogenization effect must first be determined. In this embodiment, the homogenization effect is defined as the power ratio (i.e., the power ratio described in the homogenization effect) φp between any two circular regions with a diameter of 4mm on the fiber bundle output end face. The closer this value is to 1, the better the homogenization effect. In this embodiment, the desired homogenization effect is 0.95 ≤ φp ≤ 1.05.

[0049] 6) In this embodiment, the output end face of the 1-to-3 fiber bundle is circular. To achieve the goal of high transmittance of the fiber bundle, the fiber filaments need to be closely packed in hexagons at the end face. In this case, the micro-region should be constructed as a hexagonal sub-bundle. A schematic diagram of the micro-region end face is shown below. Figure 1 As shown.

[0050] 7) Based on the zoning plan of the fiber bundle incident end face, the branch end is divided into 8 sub-zones of equal area, each numbered 1, 2, 3, ... 8. Multiple micro-zones from the corresponding sub-zone can be arranged within each sub-zone. Sub-zone number 1 corresponds to sub-zone 1 at the coarse end, and sub-zone number 8 corresponds to sub-zone 8 at the coarse end. The 18273645 regions in the fiber bundle output end face are arranged sequentially, as shown in the schematic diagram. Figure 5 As shown

[0051] 8) Determining the number of optical fibers in a micro-region: In the eight sub-regions divided by the incident end face of the aforementioned optical fiber bundle, according to... Figure 3 The incident light spot energy distribution is shown. In sub-region 1, the circular sub-region, ΔP is the largest, at 40%. To achieve the desired homogenization effect, i.e., the power ratio between any two circular regions with a diameter of 4mm on the fiber bundle exit face should be 0.95 ≤ φp ≤ 1.05, and considering the cladding outer diameter of the fiber used is 190μm, the number of fibers in a single micro-region in sub-region 1 should preferably be 19. The number of fibers x in the other 7 sub-regions is determined according to... Sure.

[0052] 9) In this embodiment, the location of the constructed micro-region starts from 100mm-150mm from the incident end. This is to avoid problems such as fiber breakage due to an excessively small constructed micro-region area and increased loss due to an excessively small fiber bending radius.

[0053] 10) After the micro-regions in each sub-region are constructed, weaving is performed within a range of 150mm-500mm from the incident end, as shown in the schematic diagram. Figure 6 As shown

[0054] 11) Pass the other end of the constructed micro-region sub-bundle through, as shown in the image. Figure 2 The inner diameter shrinking ring shown has three inner circular rings, the size of which can be freely adjusted and can move vertically.

[0055] 12) Figure 2 The inner circle of the shrinking ring is adjusted to a diameter of 15mm, causing the optical fiber passing through it to gradually converge into a circle. The height of the shrinking ring is then adjusted to be 800mm-900mm from the bottom of the optical fiber.

[0056] 13) The fiber coating of each sub-region is colored with a different color paint to distinguish the micro-region sub-bundles from different sub-regions. The heads of the light-transmitting micro-regions constructed with the above-mentioned size and shape are aligned and placed in the mold of the light-transmitting area of ​​the output end of the matching fiber bundle, arranged according to the sub-region number, and bundled to the entire end face.

[0057] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A method for zoning and weaving of optical fiber bundles and adjustable beam uniformity, characterized by, The method comprises the following steps: 1) Fiber material preparation: providing an optical fiber including a core and a cladding, and the refractive index of the core is higher than that of the cladding; 2) Fiber cutting and weaving: according to the total amount of fiber filaments required by the fiber bundle and the number of branches, the optical fiber is cut into corresponding parts in equal amounts, and the cut optical fiber is woven; 3) Light source partitioning and fiber coloring: based on the beam quality of the light source, the cross section of the light source or the incident end is divided into n equal-area sub-regions S, and each sub-region is numbered 1, 2, 3, …n, n≥2, and the optical fiber in each sub-region is colored using different paint colors; 4) Micro-region division and power balancing: each sub-region is further divided into M micro-regions, M is a multiple of N and M is greater than or equal to N, N is the number of branches in a division; in the same sub-region, the size of the micro-region is determined according to the light power difference ΔP and the required uniformity degree: The larger the maximum and minimum power difference ΔP in the sub-region, the smaller the corresponding micro-region size, and vice versa, the smaller the light power difference ΔP, the larger the corresponding micro-region size; The uniformity effect is measured by the power ratio φp of any two equal-area micro-regions on the fiber bundle exit end surface, and the closer φp is to 1, the better the uniformity effect; 5) Fiber bundle scattering and weaving: scattering and weaving the optical fiber at one end of the fiber bundle, and the length of the weaving area can be adjusted according to actual needs, which is 400-500mm; 6) Micro-region arrangement and bundling: aligning and placing the head end of the light-transmitting micro-region with the size and shape constructed in the mold matching the light-transmitting area of the fiber bundle exit end, arranging according to the sub-region number, and bundling the entire end surface.

2. The method of zoning and light beam uniformity adjustment of fiber bundle according to claim 1, wherein, The micro-region is bundled and fixed by a plurality of optical fibers, and the shape is circular, wavy, rectangular or polygonal.

3. The method of zoning and light beam uniformity adjustment of fiber bundle according to claim 2, wherein, The shape of the micro-region depends on the shape of the branch end, when the branch is circular, the micro-region is a hexagonal sub-beam, and the number of optical fibers in the micro-region is 7, 19, 37, 61…; when the branch is square, the micro-region is also square.

4. The method of zoning and uniformity adjustment of a fiber bundle according to claim 1, wherein, The size of the micro-region is also determined by the beam quality of the used light source and the diameter of the optical fiber.

5. The method of zoning and light beam uniformity adjustment of fiber bundle according to claim 4, wherein, If there is a sharp change in energy in a single region, the micro-region taken in that region needs to be further reduced; the several equal-area sub-regions S do not need to be the same shape; the smaller the diameter of the optical fiber, the smaller the micro-region that can be achieved.

6. The method of zoned weaving and beam uniformity adjustment of a fiber bundle as claimed in claim 1, wherein, The material of the mold is a high polymer material or a metal material.

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