A special optical fiber with low reflection loss and its preparation method

Abstract

A special optical fiber with low reflection loss and a preparation method thereof. The special optical fiber includes a core, a cladding, and a coating layer sequentially arranged from the inside to the outside. A heat conduction layer is arranged on the circumferential side of the coating layer. The heat conduction layer includes heat conduction wires wound around the circumferential side of the coating layer, and a gap is left between adjacent two turns of the heat conduction wires to form a heat conduction space. At least one reinforcing strip is arranged on the circumferential side of the heat conduction layer. The reinforcing strip extends along the length direction of the core, and the reinforcing strip is fixedly connected to the heat conduction wires. The present invention provides a special optical fiber with low reflection loss, which can quickly exchange heat with the surrounding environment when the ambient temperature changes, thereby avoiding local micro-bending caused by uneven thermal expansion and contraction of the optical fiber body due to different internal and external temperatures, and further avoiding the occurrence of reflection loss.

Description

Technical Field

[0001] The present invention relates to the field of optical fibers, and specifically to a special optical fiber with low reflection loss and a preparation method thereof. Background Art

[0002] An optical fiber is the abbreviation of an optical waveguide fiber, which is a fiber made of glass or plastic. It realizes the conduction of light through the principle of total internal reflection of light, and then realizes the function of transmitting information. In practical applications, it is very difficult for an optical fiber to truly conduct light without loss, and many factors will cause light to be lost and attenuated in the optical fiber. For example, when there is a local slight bend in the optical fiber, it will cause a change in the incident angle of light at the interface between the core and the cladding, and then it will not meet the total internal reflection condition, causing a part of the light to scatter out through the cladding and the coating layer, resulting in light loss. These losses caused by the inability to maintain total internal reflection can be called reflection losses. There are many situations that can cause local slight bends in the optical fiber, including limited processing accuracy or complex application environments. One of the factors is the change in the temperature of the environment where the optical fiber is located. Since the optical fiber usually has a protective layer to enhance the strength of the optical fiber, the protective layer causes the heat transfer speed on the inner and outer sides to be slow, resulting in different thermal expansion and contraction trends inside and outside the optical fiber due to different temperatures, and then causing local deformation of the optical fiber and reflection loss. Summary of the Invention

[0003] In order to solve the deficiencies in the prior art, the present invention provides a special optical fiber with low reflection loss and a preparation method thereof, which can quickly exchange heat with the surrounding environment when the environmental temperature changes, thereby avoiding local slight bends caused by uneven thermal expansion and contraction of the optical fiber body due to different internal and external temperatures, and further avoiding reflection losses.

[0004] In order to achieve the above object, the specific solution adopted by the present invention is as follows:

[0005] A special optical fiber with low reflection loss, comprising a core, a cladding, and a coating layer arranged in sequence from the inside to the outside. A heat conduction layer is arranged on the periphery of the coating layer. The heat conduction layer includes heat conduction wires wound around the periphery of the coating layer, and a gap is left between adjacent two turns of the heat conduction wires to form a heat conduction space. At least one reinforcing strip is arranged on the periphery of the heat conduction layer. The reinforcing strip extends along the length direction of the core, and the reinforcing strip is fixedly connected to the heat conduction wires.

[0006] Preferably, the cross-section of the heat conduction wire is polygonal. When the heat conduction wire is attached to the coating layer, the heat conduction wire and the coating layer are in surface contact.

[0007] Preferably, the cross-section of the heat conduction wire is a regular hexagon.

[0008] Preferably, the heat-conducting wire includes a plurality of positive spiral segments and a plurality of reverse spiral segments. Both the positive spiral segments and the reverse spiral segments are wound around the coating layer, and the positive spiral segments and the reverse spiral segments are distributed alternately.

[0009] Preferably, adjacent positive spiral segments and reverse spiral segments are connected by a transition segment. The transition segment extends along the length direction of the core and fits on the coating layer.

[0010] Preferably, the transition segment is fixed on the coating layer by a collar sleeved on the coating layer.

[0011] Preferably, the collar squeezes the reinforcing strip to form a plurality of recessed portions on the reinforcing strip, and the recessed portions are located between adjacent positive spiral segments and reverse spiral segments.

[0012] Preferably, a plurality of the reinforcing strips are provided, and the plurality of reinforcing strips are evenly distributed along the circumferential direction of the core.

[0013] Preferably, the reinforcing strip is provided with a protrusion extending to the circumferential side, and the width of the protrusion is smaller than the width of the reinforcing strip.

[0014] Preferably, the method for manufacturing the optical fiber includes the following steps:

[0015] Manufacture an optical fiber body composed of the core, the cladding, and the coating layer;

[0016] Wind the heat-conducting wire around the optical fiber body, and leave a gap between adjacent two turns of the heat-conducting wire to form the heat-conducting space;

[0017] Fix the reinforcing strip and the heat-conducting wire to be connected.

[0018] When the special optical fiber of the present invention is in use, the core, the cladding, and the coating layer form the optical fiber body, and the heat conduction layer serves as the heat exchange medium between the optical fiber body and the surrounding environment. When the temperature of the surrounding environment changes, the temperature of the optical fiber body and the surrounding environment can be quickly balanced through the heat conduction layer, ensuring that the temperature of the optical fiber body can match the temperature of the surrounding environment. Thus, it is possible to avoid the occurrence of local micro-bending caused by uneven thermal expansion and contraction of the optical fiber body due to different internal and external temperatures, and further avoid the increase in reflection loss caused by the occurrence of local micro-bending, achieving the characteristic of low reflection loss and ensuring the stability of information transmission. Also, because the heat conduction wires are wound around the optical fiber body, heat exchange between the optical fiber body and the surrounding environment can be achieved at different positions and in different directions of the optical fiber body, ensuring the heat exchange effect. And there is a gap between two adjacent turns of the heat conduction wire. On the one hand, it can form a heat conduction space, thereby expanding the heat exchange area of the heat conduction wire and improving the heat exchange efficiency. On the other hand, it can also prevent the minimum bending radius of the optical fiber body from increasing due to the heat conduction layer completely covering the optical fiber body, thus ensuring the flexibility of the optical fiber and making it easy to lay during use. In addition, by setting the reinforcing strip, various positions of the heat conduction wire can be connected, thereby enhancing the stability of the shape of the heat conduction wire, preventing the heat conduction wire from shifting due to torsion, and further ensuring that the heat conduction wire can smoothly achieve heat exchange between the optical fiber body and the surrounding environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0020] Figure 1 is a cross-sectional schematic diagram of the special optical fiber of the present invention;

[0021] Figure 2 is a structural schematic diagram of the heat conduction wire;

[0022] Figure 3 is a cross-sectional schematic diagram of the heat conduction wire;

[0023] Figure 4 is a structural schematic diagram of the collar.

[0024] Reference numerals: 1 - core, 2 - cladding, 3 - coating layer, 4 - heat conduction layer, 5 - reinforcing strip, 6 - protrusion, 7 - collar, 8 - heat conduction space, 9 - heat conduction wire, 10 - positive spiral section, 11 - reverse spiral section, 12 - transition section. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0026] As Figure 1 shown, a special fiber optic cable with low reflection loss includes a core 1, a cladding 2, and a coating layer 3 arranged in sequence from the inside to the outside. A heat conduction layer 4 is provided on the periphery of the coating layer 3. The heat conduction layer 4 includes heat conduction wires 9 wound around the periphery of the coating layer 3, and a gap is left between two adjacent turns of the heat conduction wires 9 to form a heat conduction space 8. At least one reinforcing strip 5 is provided on the periphery of the heat conduction layer 4. The reinforcing strip 5 extends along the length direction of the core 1, and the reinforcing strip 5 is fixedly connected to the heat conduction wires 9.

[0027] When the special fiber optic cable of the present invention is in use, the core 1, the cladding 2, and the coating layer 3 form the fiber optic cable main body. The heat conduction layer 4 serves as a heat exchange medium between the fiber optic cable main body and the surrounding environment. When the temperature of the surrounding environment changes, the temperature of the fiber optic cable main body and the surrounding environment can be quickly balanced through the heat conduction layer 4, ensuring that the temperature of the fiber optic cable main body can match the temperature of the surrounding environment. Thus, it is avoided that the fiber optic cable main body undergoes uneven thermal expansion and contraction due to different internal and external temperatures, resulting in local micro-bending. Furthermore, it is avoided that the reflection loss increases due to the occurrence of local micro-bending, realizing the characteristic of low reflection loss and ensuring the stability of information transmission. Also, because the heat conduction wires 9 are wound around the fiber optic cable main body, heat exchange between the fiber optic cable main body and the surrounding environment can be achieved at different positions and in different directions of the fiber optic cable main body, ensuring the heat exchange effect. And there is a gap between two adjacent turns of the heat conduction wires 9. On the one hand, it can form a heat conduction space 8, thereby expanding the heat exchange area of the heat conduction wires 9 and improving the heat exchange efficiency. On the other hand, it can also prevent the minimum bending radius of the fiber optic cable main body from increasing due to the heat conduction layer 4 completely covering the fiber optic cable main body, thus ensuring the flexibility of the fiber optic cable and making it easy to lay during use. In addition, by providing the reinforcing strip 5, various positions of the heat conduction wires 9 can be connected, thereby improving the stability of the shape of the heat conduction wires 9, preventing the heat conduction wires 9 from shifting due to torsion, and further ensuring that the heat conduction wires 9 can smoothly achieve heat exchange between the fiber optic cable main body and the surrounding environment.

[0028] In order to further improve the heat exchange efficiency of the heat conduction wires 9, the cross-section of the heat conduction wires 9 is polygonal. When the heat conduction wires 9 are attached to the coating layer 3, it is a surface contact between the heat conduction wires 9 and the coating layer 3. By making it a surface contact between the heat conduction wires 9 and the coating layer 3, the heat transfer speed between the fiber optic cable main body and the heat conduction wires 9 can be accelerated, achieving the effect of improving the heat exchange efficiency of the heat conduction wires 9. The specific shape of the cross-section of the heat conduction wires 9 can be determined according to actual needs. For example, as Figure 3As shown, in an embodiment of the present invention, the cross-section of the heat-conducting wire 9 is a regular hexagon. On the premise of ensuring surface contact between the heat-conducting wire 9 and the optical fiber body, it is also easier to attach the heat-conducting wire 9 to the coating layer 3.

[0029] As Figure 2 shown, the specific structure of the heat-conducting wire 9 is as follows: the heat-conducting wire 9 includes a plurality of positive spiral segments 10 and a plurality of reverse spiral segments 11. The positive spiral segments 10 and the reverse spiral segments 11 are both wound around the coating layer 3, and the positive spiral segments 10 and the reverse spiral segments 11 are alternately distributed. By decomposing the heat-conducting wire 9 into a plurality of positive spiral segments 10 and a plurality of reverse spiral segments 11, it is possible to prevent the overall structure of the heat-conducting wire 9 from completely becoming a spring structure, which may cause the optical fiber to be unable to be bent smoothly when the optical fiber needs to be bent due to the rebound of the heat-conducting wire 9, thus fully ensuring the flexibility of the optical fiber during use.

[0030] Furthermore, adjacent positive spiral segments 10 and reverse spiral segments 11 are connected by a transition segment 12. The transition segment 12 extends along the length direction of the core 1 and adheres to the coating layer 3. By providing the transition segment 12, adjacent positive spiral segments 10 and reverse spiral segments 11 can be separated to avoid mutual influence, making it difficult to wind the heat-conducting wire 9 around the optical fiber body. At the same time, by attaching the transition segment 12 to the optical fiber body, good heat-conducting performance can be ensured between adjacent positive spiral segments 10 and reverse spiral segments 11.

[0031] The fixing method of the heat-conducting wire 9 on the optical fiber body is as follows: the transition segment 12 is fixed to the coating layer 3 by a collar 7 sleeved on the coating layer 3. The structure of the collar 7 is as Figure 4 shown. By fixing the transition segment 12 to the coating layer 3, it is not necessary to connect the positive spiral segments 10 and the reverse spiral segments 11 to the coating layer 3. Furthermore, when winding the heat-conducting wire 9 around the optical fiber body, the distance between adjacent turns of the positive spiral segments 10 and the reverse spiral segments 11 can be adjusted as needed. When a local part of the optical fiber is prone to impact, the distance between adjacent turns of the positive spiral segments 10 and the reverse spiral segments 11 can be reduced, so as to form a protection on the circumferential side of the optical fiber body by the heat-conducting wire 9, protecting the optical fiber body, especially the core 1 and the cladding 2, and avoiding cracks or even fractures in the optical fiber body due to impact, thereby ensuring the stability of information transmission. It should also be noted that when reducing the distance between adjacent turns of the positive spiral segments 10 and the reverse spiral segments 11, it is still necessary to ensure that a heat-conducting space 8 can be formed between adjacent turns. In addition, using the collar 7 to fix the transition segment 12 to the coating layer 3 has a better fixing effect. Even if the transition segment 12 is offset, it will not be completely separated from the coating layer 3.

[0032] Further, the ferrule 7 presses the reinforcing strip 5 to form a plurality of recessed portions on the reinforcing strip 5, and the recessed portions are located between adjacent positive helical segments 10 and reverse helical segments 11. By using the ferrule 7 to form recessed portions on the reinforcing strip 5 and the recessed portions being located between adjacent positive helical segments 10 and reverse helical segments 11, the ferrule 7 can be used to limit adjacent positive helical segments 10 and reverse helical segments 11, ensuring that the distribution of the positive helical segments 10 and the reverse helical segments 11 is uniform enough, thereby ensuring the heat exchange efficiency of the heat conducting wire 9.

[0033] To enhance the effect of the reinforcing strip 5 on strengthening the heat conducting wire 9, a plurality of reinforcing strips 5 are provided, and the plurality of reinforcing strips 5 are evenly distributed along the circumferential direction of the core 1.

[0034] Further, the reinforcing strip 5 is provided with a protruding portion 6 extending towards the circumferential side, and the width of the protruding portion 6 is smaller than the width of the reinforcing strip 5. With this setting, the reinforcing strip 5 can reduce the weight on the premise of keeping the surface area unchanged, thereby reducing the overall weight of the optical fiber. The reinforcing strip 5 can also be made of the same material as the heat conducting wire 9, so as to improve the heat exchange efficiency between the optical fiber main body and the surrounding environment by the cooperation of the reinforcing strip 5 and the heat conducting wire 9. The reinforcing strip 5 and the heat conducting wire 9 can be fixed by bonding, and in one positive helical segment 10 and one reverse helical segment 11, at least one turn is connected to the reinforcing strip 5, and the rest can be directly in contact with the reinforcing strip 5 to achieve heat transfer.

[0035] In an embodiment of the present invention, the optical fiber main body is a conventional structure of an optical fiber, and its material and production process will not be elaborated here. The heat conducting wire 9 can be made of a metal material, for example, copper material. Correspondingly, the reinforcing strip 5 is also made of copper material, and the ferrule 7 can be made of PVC material. The transition section 12 is pressed tightly on the optical fiber main body by heat shrinkage to fix the heat conducting wire 9.

[0036] The preparation method of the above-mentioned low reflection loss special optical fiber includes S1 to S3.

[0037] S1. Prepare an optical fiber main body composed of a core 1, a cladding 2, and a coating layer 3.

[0038] S2. Wind the heat conducting wire 9 around the optical fiber main body, and leave a gap between adjacent two turns of the heat conducting wire 9 to form a heat conducting space 8.

[0039] S3. Fix the reinforcing strip 5 and the heat conducting wire 9 in a connected manner.

[0040] In this specification, the various embodiments are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts among the various embodiments can be referred to each other.

[0041] The foregoing description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A special optical fiber with low reflection loss, comprising a core (1), a cladding (2) and a coating layer (3) sequentially arranged from inside to outside, characterized in that, A heat-conducting layer (4) is arranged on the circumferential side of the coating layer (3), the heat-conducting layer (4) comprises a heat-conducting wire (9) wound on the circumferential side of the coating layer (3), and a gap is left between two adjacent turns of the heat-conducting wire (9) to form a heat-conducting space (8), and at least one reinforcing strip (5) is arranged on the circumferential side of the heat-conducting layer (4), the reinforcing strip (5) extends along the length direction of the fiber core (1), and the reinforcing strip (5) is fixedly connected to the heat-conducting wire (9); The heat conductive wire (9) comprises a plurality of positive helical segments (10) and a plurality of reverse helical segments (11), wherein the positive helical segments (10) and the reverse helical segments (11) are both wound on the coating layer (3), and the positive helical segments (10) and the reverse helical segments (11) are arranged in a staggered manner; adjacent positive helical segments (10) and reverse helical segments (11) are connected via a transition segment (12), and the transition segment (12) extends along the length direction of the fiber core (1) and is attached to the coating layer (3); The transition section (12) is fixed on the coating layer (3) by means of a sleeve ring (7) sleeved on the coating layer (3).

2. The special optical fiber with low reflection loss according to claim 1, characterized in that The cross section of the heat-conducting wire (9) is polygonal, and when the heat-conducting wire (9) is attached to the coating layer (3), the heat-conducting wire (9) and the coating layer (3) are in surface contact.

3. The special optical fiber with low reflection loss according to claim 2, characterized in that, The cross section of the heat conducting wire (9) is a regular hexagon.

4. The special optical fiber with low reflection loss according to claim 1, characterized in that The collar (7) presses the reinforcement strip (5) so that the reinforcement strip (5) forms a plurality of recessed portions facing the coating layer (3), and the protruding portions are located between adjacent positive helical segments (10) and reverse helical segments (11).

5. The special optical fiber with low reflection loss according to claim 1, characterized in that, The reinforcement strips (5) are arranged in plurality, and the plurality of reinforcement strips (5) are evenly distributed along the circumferential direction of the fiber core (1).

6. The special optical fiber with low reflection loss according to claim 5, characterized in that, The reinforcement strip (5) is provided with a protrusion (6) extending toward the circumferential side, and the width of the protrusion (6) is smaller than the width of the reinforcement strip (5).

7. The preparation method of a special optical fiber with low reflection loss according to any one of claims 1 to 6, characterized in that, The method comprises the following steps: Preparing an optical fiber body consisting of the fiber core (1), the cladding (2) and the coating layer (3); Winding the heat-conducting wire (9) on the optical fiber body, and leaving a gap between two adjacent turns of the heat-conducting wire (9) to form the heat-conducting space (8); The reinforcing strip (5) is fixedly connected to the heat conducting wire (9).

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