Optical fiber welding protection tube and welding optical fiber

Abstract

The utility model relates to an optical fiber welding protection tube. The optical fiber welding protection tube comprises a heat shrink tube, a hot melting tube and a supporting tube, the periphery of the supporting tube is sleeved with the hot melting tube, the periphery of the hot melting tube is sleeved with the heat shrink tube, and a plurality of liquid injection through holes are formed in the supporting tube. Compared with an optical fiber fusion welding protection tube in the prior art, the supporting tube in the optical fiber fusion welding protection tube is like a protection cage, an exclusive space is provided for the optical fiber, only flowing liquid substances are allowed to enter the exclusive space, the protection cage can protect damage from any direction in 360 degrees of the circumference, and the optical fiber fusion welding protection tube has the advantages of being simple in structure and convenient to use. And more reliable and more symmetrical supporting and protecting performance is achieved. Meanwhile, when the heat shrink tube is heated and shrunk, the heat shrink tube only wraps the outer side of the supporting tube, pressure cannot be directly conducted to the optical fiber, and the optical fiber is prevented from being bent and fractured. Compared with the scheme of a thinner supporting rod and a flat sheet in the prior art, the distributed supporting tubes are used for protecting the optical fiber on the periphery of the optical fiber, and the size after welding is smaller.

Description

Technical Field

[0001] The utility model relates to the technical field of optical fiber communication, in particular to an optical fiber fusion protection tube and an optical fiber. Background Art

[0002] With the rapid development of communication technology, the reliability and high-speed transmission capability of optical fiber communication have made it occupy a core position in the field of modern communications.

[0003] Fiber optic communication transmission relies on optical fiber interconnection, which can be divided into two types: flexible and fixed. Flexible fiber connections primarily rely on fiber optic connectors. Fixed fiber connections create a permanent connection between two optical fibers. Currently, the most commonly used fixed connection method in the field of fiber optic communications is fiber fusion splicing.

[0004] Fiber fusion splicing requires stripping the protective coating of the optical fiber before fusion splicing. After fusion splicing, the protective coating is removed from the splice area, leaving only the fragile glass fiber exposed. This is highly susceptible to external influences and breakage, so it must be protected with a fiber fusion splice protection tube. The following are currently available methods for protecting single-core and multi-core fibers after fusion splicing.

[0005] like Figure 1 As shown in Figure (a), a conventional single-core optical fiber fusion splice protective tube comprises an inner tube A12, an outer tube A13, and a support A11 disposed between the inner and outer tubes, in this case a thin support rod. The outer tube is a heat-shrinkable tube, while the inner tube is a hot-melt tube. At a certain temperature, the inner tube melts and, under the external force of the outer tube's heat contraction, encases the fused optical fibers. The thin support rod embedded in the melted inner tube provides support, preventing the fusion splice from bending under stress and potentially breaking.

[0006] However, such single-core optical fiber fusion protection tubes have the following problems:

[0007] 1) Fiber has no exclusive space

[0008] Although the thin support rod is isolated from the optical fiber by the inner sleeve before it melts, once the inner sleeve melts to form hot-melt material, the outer sleeve contracts due to the heat, forcing the hot-melt material to flow. During this flow, the thin support rod may touch the optical fiber, causing it to bend or even breaking the fusion splice on the optical fiber.

[0009] 2) Asymmetrical support settings

[0010] The support in a single-core fiber splice protection tube consists of a single thin support rod, located only on one side of the fiber. When the outer tube contracts due to heat, the fiber in the center experiences uneven forces, which can easily cause the fiber inside the tube to move erratically, resulting in bending and arching. This bending and arching of the fiber creates shear stress at the splice point, which can easily cause the splice to break.

[0011] 3) The support does not provide adequate protection for the optical fiber

[0012] The support is only a single support rod, not a hard shell, so the support cannot cope with collisions and impacts on the optical fiber from all directions, and the protection effect is not good enough.

[0013] 4) Large volume after installing the protective tube

[0014] After the single-core optical fiber fusion protection tube is installed, the support rod is set on one side of the optical fiber, which is much larger and affects the use of the fusion fiber in a narrow environment.

[0015] like Figure 1 As shown in Figure (b), the multi-core optical fiber fusion protection tube in the prior art includes: an outer sleeve A13, an inner sleeve A12, and a support A11. The two supports A11 are respectively arranged at the upper and lower positions of the optical fiber. The support here is a flat sheet, and the multi-core optical fiber is arranged in a ribbon shape. The outer sleeve is a heat shrink tube, and the inner sleeve is a hot melt tube. At a certain temperature, the inner sleeve of this optical fiber fusion protection tube melts, and under the external force of the outer sleeve shrinking due to heat, it wraps the fused optical fiber. The flat sheets located at the upper and lower positions of the optical fiber are arranged above and below the ribbon optical fiber to play a supporting and protective role, preventing the ribbon optical fiber from being subjected to external forces and causing the fusion point on the optical fiber to be disconnected.

[0016] The flat sheets of the multi-core optical fiber fusion protection tube are symmetrically arranged, which reduces the problem of the optical fiber being easily bent and arched during the melting process of the inner tube. However, the following problems still exist:

[0017] 1) Glass optical fibers bend or collide with each other

[0018] like Figure 2 As shown in (a), the coating of the ribbon optical fiber A17 is stripped to expose the glass optical fiber A15. There is a fusion point A16 on the glass optical fiber A15, and the protective tube A14 is set on the outside of the glass optical fiber A15 and the head of the ribbon optical fiber A17.

[0019] When the inner sleeve melts to form hot melt material, the outer sleeve shrinks due to heat, forcing the hot melt material to flow toward the center. Figure 2As shown in Figure (b), multiple glass optical fibers A15 are pulled together by the hot melt. During this process, the outer fibers experience severe bending, resulting in microbend losses and even disconnection of the splice A16. Furthermore, fiber-to-fiber collisions are inevitable, potentially breaking the splice A16.

[0020] 2) Multi-core fiber has no dedicated space

[0021] Since the upper and lower flat sheets are not isolated from the multi-core optical fiber, the freely set upper and lower flat sheets can still easily touch the optical fiber during the flow of the hot-melt material, causing the optical fiber to bend or even breaking the fusion splice on the optical fiber.

[0022] 3) The flat sheet does not provide adequate protection for the optical fiber

[0023] Although the flat sheet can cover the top and bottom of the optical fiber ribbon, it cannot withstand collisions from the side.

[0024] 4) Large volume after installing the protective tube

[0025] To ensure a certain strength, the flat sheet is generally designed as a solid arch. After installing the multi-core optical fiber fusion protection tube, the originally flat optical fiber will basically become cylindrical, greatly increasing its volume.

[0026] There is an urgent need for a welding protection sleeve that can solve the above problems. Utility Model Content

[0027] The utility model provides an optical fiber fusion protection tube to solve the problems of existing fusion protection tubes squeezing optical fibers, being large in size and insufficiently protecting the optical fibers.

[0028] In the first aspect, the utility model provides an optical fiber fusion protection tube, which includes a heat shrink tube, a hot melt tube and a support tube. The hot melt tube is sleeved on the outer periphery of the support tube, and the heat shrink tube is sleeved on the outer periphery of the hot melt tube. The support tube has several liquid injection holes, and the specifications of the liquid injection holes are consistent.

[0029] Furthermore, the injection through hole is circular, triangular, prismatic or polygonal.

[0030] Furthermore, the support tube has an upper flat portion and a lower flat portion, and the liquid injection through hole is only provided on the upper flat portion and the lower flat portion and / or near the upper flat portion and the lower flat portion.

[0031] Furthermore, the support tube is a metal tube.

[0032] Furthermore, the support tube is formed by curling a metal plate.

[0033] Furthermore, the hot melt tube, the heat shrink tube and the support tube are adhered and fixed to each other.

[0034] In a second aspect, the utility model provides a fusion-spliced ​​optical fiber, comprising an optical fiber with a fusion point on the optical fiber. The fusion-spliced ​​optical fiber also comprises a support tube, a hot-melt material, and a fastening material. The support tube has a plurality of liquid injection holes, and the support tube is sleeved around the outer periphery of the optical fiber. The hot-melt material is formed by the hot-melt tube melting and flowing under heat, and is filled at least inside the support tube and wraps the optical fiber. The fastening material is formed by the heat shrink tube shrinking under heat, and the fastening material is wrapped around the hot-melt material and / or the outer periphery of the support tube.

[0035] Furthermore, the injection through hole is circular, triangular, prismatic or polygonal.

[0036] Furthermore, the support tube is a metal tube.

[0037] Furthermore, the support tube is formed by curling a metal plate.

[0038] Beneficial effects

[0039] Compared with the optical fiber fusion protection tube in the prior art, the support tube in the optical fiber fusion protection tube in the utility model is like a protection cage, which is arranged on the periphery of the optical fiber to provide an exclusive space for the optical fiber. The exclusive space only allows flowing liquid substances to enter it. The protection cage can protect against damage from any angle within the 360-degree circumference, and has more reliable and symmetrical support and protection performance.

[0040] Furthermore, the injection holes on the support tube facilitate the melting process. After the hot melt tube melts, the hot melt material flows evenly from the injection holes into the support tube under the pressure generated by the heat shrinkage of the heat shrink tube. This evens out the stress on the optical fiber inside the support tube and prevents severe bending of the optical fiber caused by irregular flow of the hot melt material. Furthermore, when the heat shrink tube shrinks due to heat, it wraps around the outside of the support tube, slowing its contraction. This slows the flow of the hot melt material, lessening its impact on the optical fiber and reducing the possibility of severe bending and breakage.

[0041] Finally, compared with the thinner support rods and flat sheets in the prior art, distributed support tubes are used around the periphery of the optical fiber to protect the optical fiber, and the size after fusion is smaller. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following is a brief introduction to the drawings required for describing the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be derived from these drawings without inventive effort.

[0043] Figure 1 It is a schematic diagram of the structure of a single-core optical fiber fusion protection tube and a multi-core optical fiber fusion protection tube in the prior art;

[0044] Figure 2 It is the state of the multi-core optical fiber after the multi-core optical fiber fusion protection tube is melted and formed in the prior art;

[0045] Figure 3 Schematic diagram of the three-dimensional structure of the support tube of the single-core optical fiber fusion protection tube in Example 1;

[0046] Figure 4 Schematic diagram of the three-dimensional structure of the single-core optical fiber fusion protection tube in Example 1;

[0047] Figure 5 Schematic diagram of the end face of the single-core optical fiber fusion protection tube in Example 1;

[0048] Figure 6 1 is a schematic cross-sectional view of a single-core optical fiber after fusion splicing in Example 1;

[0049] Figure 7 This is a schematic diagram of the support tube structure of another single-core optical fiber fusion protection tube in Example 2;

[0050] Figure 8 3D schematic diagram of the support tube in the multi-core optical fiber fusion protection tube in Example 3;

[0051] Figure 9 3D schematic diagram of the multi-core optical fiber fusion protection tube in Example 3;

[0052] Figure 10 Schematic diagram of the end face of the multi-core optical fiber fusion protection tube in Example 3;

[0053] Figure 11 is a schematic cross-sectional view of the multi-core optical fiber after fusion splicing in Example 3;

[0054] Figure 12 This is a schematic diagram of the three-dimensional structure of the support tube of another multi-core optical fiber fusion protection tube in Example 3.

[0055] Description of reference numerals:

[0056] A11, support, A12, inner sleeve; A13, outer sleeve; A14, protective tube; A15, glass optical fiber; A16, fusion splice; A17, ribbon optical fiber;

[0057] 10. Optical fiber fusion protection tube; 11. Heat shrink tube; 12. Hot melt tube; 13. Support tube; 131. Liquid injection hole;

[0058] 20. Fusion-splicing optical fiber; 21. Optical fiber; 22. Hot-melt material; 23. Fastening material. DETAILED DESCRIPTION

[0059] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is 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.

[0060] In the description of the present invention, it should be understood that the terms "longitudinal," "radial," "length," "width," "thickness," "upper," "lower," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0061] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0062] The optical fiber fusion protection tube and the fusion-spliced ​​optical fiber in the present invention are described below.

[0063] It should be noted that the "heat shrink tubing" in the following description is a tubing material that shrinks when heated, and the "hot melt tubing" is a tubing material that melts when heated.

[0064] Example 1

[0065] In a first aspect, this embodiment provides an optical fiber fusion protection tube for fusing a single-core tight-buffered optical fiber with a diameter of 0.9 mm, wherein the single-core tight-buffered optical fiber with a diameter of 0.9 mm contains a 0.25 mm optical fiber and an outer plastic protective layer.

[0066] Specific as Figure 3-Figure 5 As shown, the optical fiber fusion protection tube 10 includes a heat shrink tube 11, a hot melt tube 12, and a support tube 13. The hot melt tube 12 is sleeved on the outer periphery of the support tube 13, and the heat shrink tube 11 is sleeved on the outer periphery of the hot melt tube 12. The support tube 13 has a plurality of liquid injection holes 131, through which the optical fiber to be protected can pass. In this embodiment, the support tube is a round tube.

[0067] The fiber fusion splice protective tube is placed over the fusion-spliced ​​optical fiber. The fusion zone of the fusion-spliced ​​optical fiber is placed inside the protective tube. The fusion-spliced ​​optical fiber, encased in the protective tube, is then placed in the heater of the fusion splicer. This creates a high temperature environment of 70-150°C. The heat-shrinkable tubing in the fiber fusion splice protective tube melts and, under the pressure of the heated shrink tubing, flows from the injection hole into the support tube. This completes the fusion splice.

[0068] The fused optical fiber 20 in this embodiment is as follows: Figure 6 As shown, it includes an optical fiber 21 with a fusion point on the optical fiber. The fusion-connected optical fiber 20 also includes a support tube 13, a hot-melt material 22 and a fastening material 23. The support tube 13 has a plurality of liquid injection holes 131. The support tube 13 is sleeved around the outer periphery of the optical fiber 21. The hot-melt material 22 is formed by the hot-melt tube 12 being heated, melted and flowed to fill it. It is at least filled in the interior of the support tube 13 and wraps the optical fiber 21. The fastening material 23 is formed by the heat shrink tube 11 being heated and shrunk. The fastening material 23 is wrapped around the hot-melt material 22 and / or the outer periphery of the support tube 13.

[0069] Compared with the optical fiber fusion protection tube in the prior art, the support tube in the optical fiber fusion protection tube in the utility model is like a protection cage, which is arranged on the periphery of the optical fiber to provide an exclusive space for the optical fiber. The exclusive space only allows flowing liquid substances to enter it. The protection cage can protect against damage from any angle within the 360-degree circumference, and has more reliable and symmetrical support and protection performance.

[0070] Furthermore, the injection holes on the support tube facilitate the melting process. After the hot melt tube melts, the heat shrink tubing's pressure from the heat shrink tubing shrinks as it contracts, evenly flowing through the injection holes into the support tube. This evens out the force applied to the optical fiber within the tube, preventing severe bending of the optical fiber caused by irregular flow of the hot melt material. Furthermore, as the heat shrink tubing shrinks, it wraps around the outside of the support tube, slowing its contraction. This slows the flow of the hot melt material, lessening its impact on the optical fiber and reducing the possibility of severe bending and breakage.

[0071] The outer diameter of the fiber splice protection tube in this embodiment is 2.1mm. After splicing to the optical fiber, the outer diameter shrinks slightly to 2.05mm. Compared to the 3.8mm diameter of the thin support rod solution, the fiber splice protection tube in this embodiment uses distributed support tubes around the optical fiber to protect it, compared to the existing thin support rod and flat plate solutions, resulting in a smaller size after splicing.

[0072] In this embodiment, the injection holes have the same specifications and are all circular. Of course, the shapes of the injection holes can also be other shapes, such as triangle, quadrilateral or other polygons.

[0073] In addition, in order to facilitate the mass production of optical fiber fusion protection tubes, forming liquid injection holes on small-sized support tubes is a relatively difficult process.

[0074] The researchers tried various precision machining solutions and ultimately concluded that there were several feasible options, such as using precision injection molding to form a plastic support tube, precision stamping of injection holes on metal extrusion capillaries, and forming injection holes on metal sheets before curling them into tubes.

[0075] After many experiments, demonstrations and comparisons, it was found that metal support tubes made of rolled sheets are the best choice, whether from the perspective of cost or processing convenience.

[0076] In a specific embodiment, the hot melt tube 12 is adhered to the heat shrink tube 11 and the support tube 13. This has the advantage that only slight heating of the hot melt tube is required to utilize the melting function of the hot melt tube to fix the heat shrink tube and the support tube, thus avoiding the problem of parts being lost due to the lack of any restraint between the three tubes.

[0077] Example 2

[0078] Example 2 is based on Example 1, and the shape of the liquid injection hole is improved to achieve the purpose of allowing the hot melt tube to flow from the liquid injection hole after melting and fully fill the support tube.

[0079] This embodiment and embodiment 1 both protect optical fibers with a diameter of 0.9 mm after optical fiber fusion splicing, and the similarities therein are not repeated here.

[0080] In this embodiment, the liquid injection hole 131 on the support tube 13 is a prismatic shape. Figure 7 As shown, the manufacturing process of the support tube 13 is to first form a liquid injection through hole on the metal substrate by chemical etching, and then curl the metal substrate to form a circular support tube.

[0081] Researchers discovered that the shape and distribution of the injection holes significantly influence the flow of hot melt material after melting. Experiments comparing the flow of hot melt material after melting using circular and prismatic injection holes with the same number and distribution revealed that the prismatic holes significantly outperformed the circular ones. Analyzing the melting process, researchers found that, given the same area, the prismatic holes occupy a larger axial dimension of the support tube than the circular holes. This allows for a smaller spacing between adjacent prismatic holes, making it easier for the hot melt material to fill the tube as a single unit.

[0082] Example 3

[0083] This embodiment provides an optical fiber fusion protection tube, which is used to protect a 12-core multi-core optical fiber. The multi-core optical fiber contains 12 0.25 mm optical fiber arrays and has a width of 3.0 mm.

[0084] Specific as Figures 8-10 As shown, the optical fiber fusion protection tube 10 includes a heat shrink tube 11, a hot melt tube 12, and a support tube 13. The hot melt tube 12 is sleeved around the outer periphery of the support tube 13, and the heat shrink tube 11 is sleeved around the outer periphery of the hot melt tube 12. The support tube 13 has a plurality of liquid injection holes 131, through which the optical fibers to be protected can pass. Due to the multi-core optical fiber array to be protected in this embodiment, the support tube is formed into a waist-shaped tube.

[0085] Of course, in order to provide symmetrical protection for the ribbon-shaped multi-core optical fiber array, the support tube is designed to have a symmetrical shape. Depending on the actual situation, the cross-section of the support tube can be not only waist-shaped, but also rectangular, prism-shaped, and other shapes.

[0086] The method of use is the same as in Example 1. The fiber fusion splice protective tube is placed over the outside of the fusion-spliced ​​optical fiber. The fusion zone of the fusion-spliced ​​optical fiber is placed in the protective tube. The fusion-spliced ​​optical fiber, encased in the protective tube, is then placed in the heater of the fusion splicer. The heater generates a high temperature environment of 70-150°C. The heat-shrinkable tubing in the fiber fusion splice protective tube melts and, under the pressure of the heat-shrinkable tubing shrinking due to heating, the liquid flows from the injection hole into the support tube. This completes the fusion-spliced ​​optical fiber.

[0087] The fused optical fiber 20 in this embodiment is as follows: Figure 11 As shown, it includes an optical fiber 21 with a fusion point on the optical fiber. The fusion-connected optical fiber 20 also includes a support tube 13, a hot-melt material 22 and a fastening material 23. The support tube 13 has a plurality of liquid injection holes 131. The support tube 13 is sleeved around the outer periphery of the optical fiber 21. The hot-melt material 22 is formed by the hot-melt tube 12 being heated, melted and flowed, and is at least filled in the interior of the support tube 13 and wraps the optical fiber 21. The fastening material 23 is formed by the heat shrink tube 11 being heated and shrunk, and the fastening material 23 is wrapped around the hot-melt material and / or the outer periphery of the support tube.

[0088] Compared with the optical fiber fusion protection tube in the prior art, the support tube in the optical fiber fusion protection tube in the utility model is like a protection cage, providing an exclusive space for the optical fiber. The exclusive space only allows flowing liquid substances to enter it. The protection cage can protect against damage from any direction in the 360-degree circumference, and has more reliable and symmetrical support and protection performance.

[0089] In this embodiment, after the fiber fusion splice protection tube is fused to the optical fiber, the splice remains flat, with a maximum dimension of approximately 5.0 mm. Compared to the double-flat plate solution, where the splice is a cylindrical 5.8 mm diameter, the fiber fusion splice protection tube in this embodiment uses distributed support tubes around the optical fiber to protect it, compared to the existing solution with thinner support rods and flat plates. This results in a smaller size after the splice.

[0090] In a specific embodiment, the support tube is as follows Figure 12 As shown, the support tube has an upper flat portion and a lower flat portion, and the liquid injection through-holes 131 are only provided on the upper flat portion and the lower flat portion.

[0091] The reason for this design is that the researchers found that if liquid injection holes are set on the upper flat part, lower flat part and left and right sides of the relatively flat waist-shaped support tube, when it is used to protect the fused optical fiber, the pressure of the melted hot-melt material flowing to the left and right sides is relatively high, which causes the optical fibers on both sides of the multi-core optical fiber to bend toward the middle.

[0092] After removing the liquid injection holes on the left and right sides of the support tube, the hot melt material only flows into the support tube from the upper flat part and the lower flat part. In this way, the hot melt material cannot squeeze the optical fiber from the two outsides, thereby eliminating the possibility of the optical fiber being severely bent inward and broken.

[0093] In addition, providing the liquid injection holes 131 near the upper flat portion and the lower flat portion can also alleviate the situation where the optical fibers on both sides of the multi-core optical fiber bend toward the middle to a certain extent.

[0094] The above-described embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should all be included in the scope of protection of the present invention.

Claims

1. An optical fiber fusion protection tube, characterized in that: It includes a heat shrink tube, a hot melt tube and a support tube. The hot melt tube is sleeved on the outer periphery of the support tube. The heat shrink tube is sleeved on the outer periphery of the hot melt tube. The support tube is provided with a plurality of liquid injection holes, and the specifications of the liquid injection holes are consistent.

2. The optical fiber fusion protection tube according to claim 1, characterized in that: The injection through hole is circular, triangular, prismatic or polygonal.

3. The optical fiber fusion protection tube according to claim 2, characterized in that: The support tube has an upper flat portion and a lower flat portion, and the liquid injection through hole is only provided on the upper flat portion and the lower flat portion and / or near the upper flat portion and the lower flat portion.

4. The optical fiber fusion protection tube according to claim 1, characterized in that: The support tube is a metal tube.

5. The optical fiber fusion protection tube according to claim 4, characterized in that: The support tube is formed by curling a metal plate.

6. The optical fiber fusion protection tube according to claim 1, characterized in that: The hot melt tube, the heat shrink tube and the support tube are adhered and fixed to each other.

7. A fusion-connected optical fiber, comprising an optical fiber, characterized in that: It also includes a support tube, a hot-melt material and a fastening material. The support tube is provided with a plurality of liquid injection holes. The support tube is sleeved around the outer periphery of the optical fiber. The hot-melt material is formed by the hot-melt tube melting and flowing under heat. It at least fills the interior of the support tube and wraps the optical fiber. The fastening material is formed by the heat shrink tube shrinking under heat. The fastening material is wrapped around the hot-melt material and / or the outer periphery of the support tube.

8. The fusion-spliced ​​optical fiber according to claim 7, wherein: The injection through hole is circular, triangular, prismatic or polygonal.

9. The fusion-spliced ​​optical fiber according to claim 7, wherein: The support tube is a metal tube.

10. The fusion-spliced ​​optical fiber according to claim 9, wherein: The support tube is formed by curling a metal plate.

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