A gradient optical fiber manufacturing system and manufacturing method thereof

Abstract

The present application provides a gradient optical fiber manufacturing system and a manufacturing method thereof, the gradient optical fiber manufacturing system comprises a feeding device, a drawing device, a sleeve and a controller, and a flame spraying device arranged between the feeding device and the drawing device; the feeding device comprises a first driving device and a first transmission device driven by the first driving device, the drawing device comprises a second driving device and a second transmission device driven by the second driving device, the controller is used to control the rotation speed of the first driving device, the differential rotation of the second driving device, and the flame switch, heat and time of the flame spraying device. The sleeve is located at the flame spraying heating position of the flame spraying device, and the sleeve has openings on both sides. The optical fiber to be processed enters the interior of the sleeve from the opening on one side of the sleeve and then passes through the opening on the other side. The sleeve allows the optical fiber to be heated evenly when heated, and is not easy to cause deformation of the optical fiber.

Description

Technical Field

[0001] The present application relates to the field of optical fiber technology, and in particular to a gradient optical fiber manufacturing system and a manufacturing method thereof. Background Art

[0002] High-power all-fiber large pulse energy (femtosecond, picosecond, nanosecond) lasers are widely used in the fields of new energy, semiconductors, precision micro-machining of aerospace and national defense due to their narrow pulse width, large single pulse energy, and high repetition frequency. Compared with solid-state lasers and titanium sapphire lasers, ultrashort pulse lasers realized by all-fiber laser solutions have the advantages of low cost, simple structure, high efficiency, and good stability, which are more conducive to large-scale industrial applications.

[0003] In some existing application fields that require the use of optical fibers, such as mode field adapters and laser amplifiers, gradient-index optical fibers are needed. The so-called gradient-index optical fibers refer to optical fibers whose diameter gradually decreases or increases along the axis of the optical fiber.

[0004] The existing technical solutions for making gradient optical fibers can be roughly divided into two production methods: one is to draw the fiber through a drawing tower device with an electric heating furnace. The electric heating furnace can provide uniform heating for the optical fiber, and the produced optical fiber is of good quality and basically will not deform. However, the current drawing tower device has a complex structure, a huge volume, and is expensive. The second is to heat the ordinary uniform core diameter optical fiber to a softened state through a hydrogen-oxygen flame, and stretch it to one side or both sides to form a gradient optical fiber. The stretched length of the optical fiber is generally short, and the shape is difficult to control. In addition, due to the different thicknesses of the gradient optical fiber at different positions, the stress on the optical fiber will change continuously during the stretching process. In addition, when the flame is heated, the side close to the flame heats up quickly and the relative temperature is also higher, while the side away from the flame heats up relatively slowly and the relative temperature is also lower. It is very easy for the optical fiber to bend and deform or even break due to uneven heating, and it is difficult to obtain a straight gradient optical fiber. The refraction of light by the bent optical fiber will change, which seriously affects the quality of the optical fiber. Moreover, when the hydrogen-oxygen flame is directly processed on the optical fiber, the optical fiber will produce hydrogen and oxygen radicals, which will also have a certain impact on the beam quality. Summary of the invention

[0005] The present application provides a gradient optical fiber manufacturing system and a manufacturing method thereof, aiming to solve the technical problem that the conventional gradient optical fiber manufacturing system has poor controllability in the optical fiber stretching manufacturing process.

[0006] The present application provides a gradient optical fiber manufacturing system and a manufacturing method thereof, the gradient optical fiber manufacturing system comprises a feeding device, a drawing device, a sleeve and a controller, and a flame spraying device arranged between the feeding device and the drawing device; the feeding device comprises a first driving device and a first transmission device driven by the first driving device, the drawing device comprises a second driving device and a second transmission device driven by the second driving device, the controller is used to control the rotation speed of the first driving device, the rotation speed of the second driving device, and the flame switch, heat and time of the flame spraying device. The sleeve is located at the flame spraying heating position of the flame spraying device, and the sleeve has openings on both sides, and the optical fiber to be processed enters the interior of the sleeve from the opening on one side of the sleeve and then passes out from the opening on the other side.

[0007] In a specific solution of the present application, the controller controls the rotation speed of the first drive device and the second drive device to satisfy: the first drive device and the second drive device drive the first transmission device and the second transmission device to rotate differentially.

[0008] In a specific solution of the present application, the gradient optical fiber manufacturing system further includes a fiber coiling device arranged opposite to the drawing device, the fiber coiling device includes a third driving device and a fiber coiling wheel driven by the third driving device, and the controller is further used to control the rotation speed of the third driving device. The rotation speeds of the second driving device and the third driving device satisfy: the second driving device and the third driving device drive the fiber coiling wheel and the second transmission device to rotate at the same speed.

[0009] In a specific solution of the present application, the gradient optical fiber production system also includes a gluing device arranged between the drawing device and the fiber coiling device, and the gluing device includes a gluing machine and a curing machine arranged between the gluing machine and the fiber coiling device.

[0010] The present application also provides a method for manufacturing a gradient optical fiber applicable to the gradient optical fiber manufacturing system as described above, the method for manufacturing a gradient optical fiber comprising the following steps:

[0011] Winding the optical fiber: the optical fiber is attached to the first transmission device and the second transmission device at the same time, and the first transmission device and / or the second transmission device are controlled to rotate until the optical fiber is straightened;

[0012] Stretching and manufacturing optical fiber: the controller controls the flame-throwing device to heat the optical fiber, and the controller controls the first transmission device and the second transmission device to rotate at a differential speed to achieve stretching and manufacturing of the optical fiber.

[0013] In other embodiments of the present application, after the step of drawing and manufacturing the optical fiber, the method further comprises:

[0014] Applying glue layer: the controller controls the glue coating machine to apply a protective glue layer to the optical fiber after being stretched and formed, and the controller controls the curing machine to cure the protective glue layer coated on the outer surface of the optical fiber;

[0015] Fiber coiling: the controller controls the fiber coiling wheel and the second transmission device to rotate at the same speed, so that the optical fiber coated with the protective rubber layer is wound around the fiber coiling wheel.

[0016] When the gradient optical fiber manufacturing system provided by the present application is stretched to manufacture optical fiber, the controller controls the first driving device and the second driving device to drive the first transmission device and the second transmission device to rotate differentially respectively, and controls the flame device to heat the optical fiber to soften it. At the same time, since the gradient optical fiber manufacturing system of the present application is provided with a sleeve, when the flame device heats the optical fiber by flame spraying, the flame first contacts the sleeve, and then conducts the heat to the optical fiber, and the sleeve surrounds the outside of the optical fiber to form a partially closed thermal environment, so that when the optical fiber is heated, the heating difference between the side close to the flame and the side away from the flame is not large, and the overall heating is relatively uniform, and a linear gradient optical fiber can be stretched to manufacture, and it is not easy to cause the optical fiber to bend and deform, thereby ensuring the quality of the optical fiber, and no complex drawing tower device is required. The optical fiber facing the flame device is stretched under the differential rotation of the first transmission device and the second transmission device. Such a scheme can make the optical fiber stretched under the temperature conditions of a controllable uniform environment, and the stretching rate is directly controlled by the speed difference between the first transmission device and the second transmission device, so that the stretching can be controlled according to actual needs to manufacture optical fibers of specific shapes, such as tapered optical fibers, shuttle optical fibers, or gourd-shaped optical fibers. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions of the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 is a schematic structural diagram of a gradient optical fiber manufacturing system provided in the first embodiment of the present application;

[0019] Figure 2 is a structural schematic diagram of a gradient optical fiber manufacturing system provided in a second embodiment of the present application;

[0020] Figure 3is a schematic diagram of the diameter change of an optical fiber produced by stretching the gradient optical fiber production system provided in an embodiment of the present application;

[0021] Figure 4 is a schematic structural diagram of a gradient optical fiber manufacturing system provided in a third embodiment of the present application;

[0022] Figure 5 It is a schematic diagram of the structure of the feeding device of the present application;

[0023] Figure 6 is a structural schematic diagram of a gradient optical fiber manufacturing system provided in a fourth embodiment of the present application;

[0024] Figure 7 It is a schematic diagram of the process of manufacturing a gradient optical fiber provided in an embodiment of the present application.

[0025] Figure numerals: 1. feeding device; 11. first driving device; 12. first transmission device; 121. first optical fiber groove; 13. first auxiliary transmission device; 14. first bracket; 2. flamethrower; 21. heat source; 3. wire drawing device; 31. second driving device; 32. second transmission device; 33. second auxiliary transmission device; 4. sleeve; 5. fiber coiling device; 51. third driving device; 52. fiber coiling wheel; 6. glue coating device; 61. glue coating machine; 62. curing machine; 7. monitoring device; 8. optical fiber. DETAILED DESCRIPTION

[0026] In order to enable those skilled in the art to better understand the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application.

[0027] It should be noted that when a component is referred to as being "fixed on" or "disposed on" another component, it may be directly or indirectly located on the other component. When a component is referred to as being "connected to" another component, it may be directly or indirectly connected to the other component. The directions or positions indicated by the terms "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are based on the directions or positions shown in the accompanying drawings and are only for the convenience of description and cannot be understood as limitations on the present technical solution. The terms "first" and "second" are only used for the convenience of description and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features. "Multiple" means two or more, unless otherwise clearly and specifically defined.

[0028] In order to illustrate the technical solution described in this application, a detailed description is given below in conjunction with specific drawings and embodiments.

[0029] See also Figure 1 , Figure 1 1 is a schematic diagram of the structure of a gradient optical fiber production system provided in the first embodiment of the present application. The present application provides a gradient optical fiber production system, which includes a feeding device 1, a drawing device 3, a controller (not shown in the figure), and a flamethrower 2 arranged between the feeding device 1 and the drawing device 3; the feeding device 1 includes a first driving device 11 and a first transmission device 12 driven by the first driving device 11, the drawing device 3 includes a second driving device 31 and a second transmission device 32 driven by the second driving device 31, and the controller can be used to control the rotation speed of the first driving device 11, the rotation speed of the second driving device 31, and the flame switch, heat and time of the flamethrower 2.

[0030] The special feature of the present application is that an embodiment of the present application provides a gradient optical fiber manufacturing system further provided with a sleeve 4, the sleeve 4 is located at the flame-spraying heating position of the flame-spraying device 2, the sleeve 4 has openings on both sides, and the optical fiber 8 to be processed enters the interior of the sleeve 4 from the opening on one side of the sleeve 4, and then passes through the opening on the other side. When the flame-spraying device 2 is heated by the flame, the flame first contacts the sleeve 4, and then conducts the heat to the optical fiber 8. Since the sleeve 4 surrounds the outside of the optical fiber 8, when the optical fiber 8 is heated, the heating difference between the side close to the flame and the side far from the flame is not much, and the overall heating is relatively uniform, which is not easy to cause the optical fiber to bend and deform.

[0031] The operation mode of the gradient optical fiber production system of this embodiment is as follows: the optical fiber 8 to be stretched and produced is simultaneously attached to the first transmission device 12 and the second transmission device 32, and the first transmission device 12 and / or the second transmission device 32 are controlled to rotate until the optical fiber 8 is straightened; then, the flamethrower 2 is controlled by a controller to heat the optical fiber 8 by flame spraying, so that part of the optical fiber 8 is heated and softened, and at the same time, the first driving device 11 and the second driving device 31 are controlled by the controller, and the first driving device 11 and the second driving device 31 are driven to drive the first transmission device 12 and the second transmission device 32 to rotate at a differential speed, specifically, the rotation speed of the first transmission device 12 is less than or equal to the rotation speed of the second transmission device 32, and driven by the first transmission device 12 and the second transmission device 32, the optical fiber 8 moves in the direction from the first transmission device 12 to the second transmission device 32.

[0032] In this way, since there is a speed difference between the first transmission device 12 and the second transmission device 32, and the optical fiber 8 is simultaneously close to the first transmission device 12 and the second transmission device 32 under the influence of friction, the section of the optical fiber 8 that is heated by the flamethrower 2 is softened, and when the speed of the first transmission device 12 is less than the speed of the second transmission device 32, under the action of the tension, the optical fiber 8 becomes longer and thinner. By controlling the speed difference between the first transmission device 12 and the second transmission device 32, the degree of stretching of the optical fiber 8 can be controlled, thereby realizing the controllable stretching of the optical fiber 8. Specifically, the present application can make the optical fiber 8 stretched under controllable temperature conditions. Since the optical fiber 8 is quantitatively heated and quantitatively stretched under controllable conditions, the optical fiber 8 can be controlled not to break during the stretching process, thereby improving the stability of the production process when the optical fiber 8 is stretched and formed.

[0033] The present application directly controls the stretching rate of the optical fiber 8 by controlling the speed difference between the first transmission device 12 and the second transmission device 32, and then can stretch and produce the optical fiber 8 of a specific gradient shape according to actual needs. The gradient optical fiber stretched and produced by the present application can be a tapered optical fiber, a shuttle optical fiber, a gourd-shaped optical fiber or other gradient-shaped optical fibers, and the optical fiber diameter can gradually become smaller, or gradually increase, or sometimes become smaller and sometimes increase.

[0034] However, the optical fiber 8 is generally made of quartz glass material, and its heating softening temperature usually needs to be more than 1400 degrees Celsius. In order to achieve the reliability of the gradient optical fiber manufacturing system of the present application, the manufacturing material of the sleeve 4 of the gradient optical fiber manufacturing system of the present application is made of a material with a melting point greater than or equal to that of the optical fiber 8 and good thermal conductivity, usually high-purity quartz or high-temperature resistant ceramic material.

[0035] In addition, when high-temperature resistant ceramics are used as the manufacturing material of the sleeve 4 , the heating temperature may be relatively high, and the sleeve 4 may contaminate the optical fiber 8 during the stretching process, thereby affecting the quality of the optical fiber 8 .

[0036] When quartz is used as the material for making the sleeve 4, since the optical fiber 8 is generally also made of quartz glass, although the sleeve 4 will not contaminate the optical fiber 8, the sleeve 4 may soften before the optical fiber 8, and the reliability of the gradient optical fiber manufacturing system is difficult to ensure.

[0037] To solve the above problems, see Figure 2 , Figure 2: is a schematic diagram of the structure of the gradient optical fiber manufacturing system provided by the second embodiment of the present application. When the sleeve 4 of the present application is made of quartz as a manufacturing material, the sleeve 4 is provided with a plurality of microholes at least on one side close to the flamethrower 2. When the flamethrower 2 is emitting flames, the outer flame of the flamethrower 2 can pass through the microholes into the sleeve 4, and the sleeve 4 is in direct contact with the inner flame or the flame core of the flamethrower 2. Since the temperature of the inner flame or the flame core is lower than the temperature of the outer flame, the optical fiber 8 can be softened before the sleeve 4 by controlling the size, number, and distance of the flamethrower 2 and the microholes, so as to improve the reliability of the gradient optical fiber manufacturing system. At the same time, the scheme utilizes the setting of the sleeve 4 surrounding the optical fiber 8 to form a locally closed thermal environment, and diffuses the flame entering the sleeve 4 through the microholes, so as to improve the uniformity of heating of the optical fiber 8 in all directions.

[0038] Furthermore, the flame-throwing device 2 may be one or more.

[0039] Furthermore, in a preferred embodiment, the number of the flamethrower devices 2 can be two or four. When there are two flamethrower devices 2, they are arranged on two opposite sides of the outside of the sleeve 4. When there are four flamethrower devices 2, they are arranged opposite to each other in pairs.

[0040] It should be noted that the design scheme of the sleeve 4 having micropores is not limited to quartz materials, but quartz materials as the manufacturing material of the sleeve 4 can avoid bringing additional impurities to the optical fiber 8 as much as possible. For other high-temperature resistant and thermally conductive materials with a melting point greater than or equal to the optical fiber 8 and good thermal conductivity, micropore structures can also be designed. Similarly, the size, number, and distance of the flame-spraying device 2 and the micropores can be controlled to make the optical fiber 8 soften before the sleeve 4, so as to improve the reliability of the gradient optical fiber manufacturing system. The refractory and high-temperature resistant materials mentioned here naturally include refractory ceramic materials.

[0041] See also Figure 3 The gradient fiber manufacturing system provided in this embodiment can effectively stretch the optical fiber 8 with a cladding diameter in the range of 50 to 1500 μm to prepare a gradient fiber with a length of 0.1 to 10 m. In some embodiments, the optical fiber 8 can be stretched to a length of 10 m without breaking. In some embodiments, a 2 m long gradient fiber is stretched and manufactured using the gradient fiber manufacturing system described above, and the M of the output light spot at the thicker end of the optical fiber 8 is 2 The value can be within 1.2, the ellipticity can reach above 0.98, the error range of the fiber 8 diameter is within 5μm, the fiber 8 diameter has a smooth transition and there are no burrs on the fiber 8 surface, which can fully meet the performance requirements of the laser amplifier or mode field adapter for gradient optical fiber.

[0042] For example, when a tapered optical fiber is used in a laser amplifier, since the core diameter and cladding diameter of the tapered optical fiber are extremely slender and tapered, when the pump light is incident from the thick end of the gradient optical fiber, the number of times the pump light is reflected in the optical fiber 8 and the number of times it passes through the core can be greatly increased, thereby increasing the utilization rate of the rare earth ions doped in the tapered optical fiber, and thus being able to obtain the same laser power amplification factor with one-third of the length of the ordinary optical fiber 8.

[0043] Furthermore, the gradient optical fiber produced by stretching the gradient optical fiber production system provided in this embodiment has the advantages of good light beam quality and is not easily affected by external vibration, bending of the optical fiber 8, and other factors. Specifically, when the signal light is transmitted in the core of the ordinary large mode area optical fiber 8, due to the large core diameter, the light beam is fully reflected back and forth in the core diameter. The vibration and bending will affect the signal light reflected and transmitted in the core, making its light spot worse, generating a high-order mode, and its output light spot shape changes from a pure circular Gaussian light spot to an ellipse or even multiple light spots.

[0044] See also Figure 4 , Figure 4 : is a schematic diagram of the structure of the gradient optical fiber manufacturing system provided in the third embodiment of the present application. In this embodiment, the gradient optical fiber manufacturing system also includes a fiber coiling device 5 arranged opposite to the drawing device 3, and the fiber coiling device 5 includes a third driving device 51 and a fiber coiling wheel 52 driven by the third driving device 51. The controller is also used to control the rotation speed of the third driving device 51. Specifically, the controller controls the third driving device 51 to rotate, thereby driving the fiber coiling wheel 52 to rotate, so that the stretched optical fiber 8 can be continuously wound on the fiber coiling wheel 52 to prevent the optical fiber 8 from breaking during the stretching process.

[0045] In this embodiment of the present application, the rotation speeds of the first drive device 11, the second drive device 31 and the third drive device 51 satisfy: the fiber coiling wheel 52 and the second transmission device 32 rotate at the same speed, and the first transmission device 12 and the second transmission device 32 rotate at a differential speed. The fiber coiling wheel 52 and the second transmission device 32 rotate at the same speed to ensure that the optical fiber 8 after stretching can be evenly wound on the fiber coiling wheel 52 to prevent the optical fiber 8 from breaking during the stretching process. The first transmission device 12 and the second transmission device 32 rotate at a differential speed to stretch the portion of the optical fiber 8 facing the flamethrower 2. Specifically, the rotation speed of the first transmission device 12 is less than or equal to the rotation speed of the second transmission device 32.

[0046] It should be understood that in this embodiment, the fiber disc wheel 52 and the second transmission device 32 rotate at the same speed, and the first transmission device 12 and the second transmission device 32 rotate at a differential speed respectively refer to that, under the drive of the first drive device 11, the second drive device 31 and the third drive device 51, the fiber disc wheel 52 and the second transmission device 32 rotate at the same linear speed, and the first transmission device 12 and the second transmission device 32 rotate synchronously with a certain linear speed difference. The relevant descriptions of the rotation speeds of the first transmission device 12, the second transmission device 32 and the fiber disc wheel 52 in various places of this application all refer to the linear speeds of the first transmission device 12, the second transmission device 32 and the fiber disc wheel 52.

[0047] See also Figure 5 In this embodiment of the present application, the gradient optical fiber manufacturing system further includes a glue coating device 6 disposed between the drawing device 3 and the fiber coiling device 5, and the glue coating device 6 includes a glue coating machine 61 and a curing machine 62 disposed between the glue coating machine 61 and the fiber coiling device 5. The optical fiber 8 manufactured by drawing first passes through the glue coating machine 61, where a protective glue layer is evenly coated, and then the protective glue layer is cured at the curing machine 62, thereby forming a protective glue layer on the outside of the optical fiber 8 that can prevent the optical fiber 8 from being broken.

[0048] As a specific solution of this embodiment, the glue coating machine 61 adopts a tubular glue coating machine 61 to evenly coat the protective glue layer on the outside of the stretched optical fiber 8. As a specific solution of this embodiment, the curing machine 62 includes an ultraviolet light source, and the ultraviolet light source is used as the light source of the curing equipment of the protective glue layer, which has the characteristics of long lamp life, low heat generation, high energy utilization rate, and excellent curing efficiency and curing uniformity; More preferably, the ultraviolet light source can include a plurality of ultraviolet lamps evenly arranged around the optical fiber 8, and the combined power of the plurality of ultraviolet lamps is greater than or equal to 500w, so as to further improve the uniformity and efficiency of curing the protective glue layer.

[0049] As a specific solution of this embodiment, the protective adhesive layer of the optical fiber 8 may need to be stripped off first before being stretched; or, the gradient optical fiber manufacturing system directly stretches the fiber core without a protective layer, and then coats the protective adhesive layer and solidifies it.

[0050] See also Figure 4 In this embodiment of the present application, the gradient optical fiber manufacturing system further includes a monitoring device 7 disposed between the flame spraying device 2 and the glue coating device 6, and the monitoring device 7 is used to monitor the diameter of the optical fiber 8 after being stretched by the feeding device 1 and the drawing device 3. The purpose of setting the monitoring device 7 is to be able to analyze and process the data such as the diameter and length change of the optical fiber 8, and at the same time, to be able to issue a warning when the working state of the gradient optical fiber manufacturing system is abnormal, such as when the optical fiber 8 is broken.

[0051] As a specific implementation of this embodiment, the monitoring device 7 is arranged between the flame spraying device 2 and the wire drawing device 3. The monitoring device 7 is facing the optical fiber 8 after stretching. During the whole process of stretching, the image of the gradient optical fiber produced by stretching is collected. The controller determines the diameter of the optical fiber 8 after stretching according to the image collected by the monitoring device 7, and controls the diameter of the produced optical fiber 8 to meet the actual production needs. In addition, the controller also generates data such as the diameter and length change of the optical fiber 8 according to the image collected by the monitoring device 7.

[0052] See also Figure 5 , Figure 5 The schematic diagram of the structure of the feeding device of the present application is shown in FIG. The first transmission device 12 of the feeding device is provided with a first fiber groove 121 for clamping the optical fiber 8. The first fiber groove 121 is arranged around the first transmission device 12. The purpose of setting the first fiber groove 121 is to enable the optical fiber 8 to be attached to the surface of the first transmission device 12 along the first fiber groove 121. Specifically, the diameter of the first fiber groove 121 is smaller than the diameter of the optical fiber 8. The first fiber groove 121 applies a clamping force and a friction force to the optical fiber 8, clamping the optical fiber 8 and preventing the optical fiber 8 from deviating from the position of the heating and stretching production.

[0053] See also Figure 6 , Figure 6 : is a schematic diagram of the structure of the gradient optical fiber manufacturing system provided in the fourth embodiment of the present application. The feeding device 1 of the gradient optical fiber manufacturing system of this embodiment also includes a first auxiliary transmission device 13 arranged opposite to the first transmission device 12, the axis of the first auxiliary transmission device 13 is parallel to the axis of the first transmission device 12, and the first auxiliary transmission device 13 is tangent to the first transmission device 12. The first auxiliary transmission device 13 tangent to the first transmission device 12 can not only further prevent the optical fiber 8 from deviating from the normal position, but also increase the friction between the optical fiber 8 and the first transmission device 12, so as to prevent the optical fiber 8 from slipping during the heating and stretching process.

[0054] In an embodiment of the present application, the second transmission device 32 is provided with a second optical fiber groove for clamping the optical fiber 8. The second optical fiber groove is arranged around the second transmission device 32. The purpose of setting the second optical fiber groove is to enable the optical fiber 8 to be attached to the surface of the second transmission device 32 along the second optical fiber groove 321. Similarly, the diameter of the second optical fiber groove is smaller than the diameter of the optical fiber 8. The function of the second optical fiber groove is similar to that of the first optical fiber groove 121, which will not be repeated here.

[0055] In the embodiment of the present application, the wire drawing device 3 further includes a second auxiliary transmission device 33 arranged opposite to the second transmission device 32, the axis of the second auxiliary transmission device 33 is parallel to the axis of the second transmission device 32, and the second auxiliary transmission device 33 is tangent to the second transmission device 32. Similarly, the function of the second auxiliary transmission device 33 arranged tangent to the second transmission device 32 is similar to that of the first auxiliary transmission device 13, and will not be repeated here.

[0056] Furthermore, in one embodiment of the present application, the gradient optical fiber manufacturing system further includes a workbench (not shown in the figure) for installing the feeding device 1, the flame spraying device 2 and the drawing device 3. Figure 6 The feeding device 1 also includes a first bracket 14, and the first driving device 11 is connected to the workbench through the first bracket 14, which can improve the stability of the overall structure.

[0057] Furthermore, the wire drawing device 3 also includes a second bracket (not shown in the figure), and the second driving device 31 is connected to the workbench through the second bracket, which can also improve the stability of the overall structure.

[0058] Furthermore, the fiber coiling device 5 also includes a third bracket for installing the fiber coiling wheel 52 and the first driving device 51, and the third bracket is arranged on the side of the wire drawing device 3 away from the feeding device 1; the monitoring device 7 also includes a fourth bracket for installing the monitoring device 7 on the workbench, which can also improve the stability of the overall structure.

[0059] Furthermore, the heat source 21 of the flamethrower 2 adopts a hydrogen-oxygen flame heat source 21. More specifically, the hydrogen-oxygen flame heat source 21 may include an air supply flame head pipe, a gas flow meter, and a hydrogen source and an oxygen source connected to the air supply flame head pipe. The controller can simultaneously control the flow rates of hydrogen and oxygen, thereby changing the flame temperature and the heating range during the tapering process of the optical fiber 8.

[0060] See also Figure 7 One embodiment of the present application provides a method for manufacturing a gradient optical fiber applicable to the gradient optical fiber manufacturing system as described above. Specifically, the method for manufacturing a gradient optical fiber comprises the following steps:

[0061] S1: Winding the optical fiber: The optical fiber 8 is simultaneously attached to the first transmission device 12 and the second transmission device 32, and the first transmission device 12 and / or the second transmission device 32 are controlled to rotate until the optical fiber 8 is straightened;

[0062] S2: Stretching and manufacturing optical fiber: the controller controls the flame-spraying device 2 to heat the optical fiber 8 , and the controller controls the first transmission device 12 and the second transmission device 32 to rotate at a differential speed, so as to realize the stretching and manufacturing of the optical fiber 8 .

[0063] In the method for manufacturing a graded-index optical fiber provided in the present embodiment, the controller controls the first driving device 11 and the second driving device 31 to respectively drive the first transmission device 12 and the second transmission device 32 to rotate at a differential speed, and at the same time controls the flamethrower 2 to heat the optical fiber 8 to soften it. The optical fiber 8 facing the flamethrower 2 is stretched under the differential rotation of the first transmission device 12 and the second transmission device 32, so that the optical fiber 8 can be stretched under controllable temperature conditions, and the stretching rate is directly controlled by the speed difference between the first transmission device 12 and the second transmission device 32, so that the optical fiber 8 of a specific shape can be stretched according to actual needs, such as various graded-index optical fibers such as tapered optical fibers, shuttle optical fibers or gourd-shaped optical fibers; because the optical fiber 8 is quantitatively heated and quantitatively stretched under controllable conditions, the optical fiber 8 can be prevented from breaking during the stretching process, thereby increasing the maximum length of the optical fiber 8 formed by stretching.

[0064] When the flame-throwing device 2 is heating by flame-throwing, the flame first contacts the sleeve 4 and then conducts the heat to the optical fiber 8. Since the sleeve 4 surrounds the outside of the optical fiber 8, when the optical fiber 8 is heated, the heating difference between the side close to the flame and the side far from the flame is not much, and the overall heating is relatively uniform, which is not easy to cause the optical fiber to bend and deform.

[0065] In one embodiment of the present application, after the step of drawing and manufacturing the optical fiber 8, the method further includes:

[0066] S3: Applying a rubber layer: The controller controls the rubber coating machine 61 to apply a protective rubber layer to the stretched optical fiber 8, and the controller controls the curing machine 62 to cure the protective rubber layer coated on the outer surface of the optical fiber 8;

[0067] S4: Fiber coiling: The controller controls the fiber coiling wheel 52 to rotate at the same speed as the second transmission device 32 , so that the optical fiber 8 coated with the protective adhesive layer is wound around the fiber coiling wheel 52 .

[0068] The stretched optical fiber 8 first passes through the glue coater 61, where it is evenly coated with a protective glue layer, and then the protective glue layer is cured at the curing machine 62, thereby forming a protective glue layer on the outside of the optical fiber 8 that can prevent the optical fiber 8 from being broken; the controller controls the third drive device 51 to rotate, thereby driving the fiber winding wheel 52 to rotate, so that the stretched optical fiber 8 can be continuously wound on the fiber winding wheel 52 to prevent the optical fiber 8 from breaking during the stretching process.

[0069] Specific embodiments are used herein to illustrate the principles and implementation methods of the present application, and the description of the above embodiments is only used to help understand the method and its core idea of ​​the present application. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and the various embodiments in the present application can be combined, and these improvements, modifications and combinations also fall within the scope of protection of the claims of the present application, that is, the claims of the present application can arbitrarily combine the embodiments of the present application, and are not limited to the limited combination of the embodiments provided in the present application.

Claims

1. A gradient optical fiber manufacturing system, characterized in that: The invention comprises a feeding device (1), a wire drawing device (3), a sleeve (4) and a controller, and a flame spraying device (2) arranged between the feeding device (1) and the wire drawing device (3); the feeding device (1) comprises a first driving device (11) and a first transmission device (12) driven by the first driving device (11); the wire drawing device (3) comprises a second driving device (31) and a second transmission device (32) driven by the second driving device (31); the controller is used to control the rotation speed of the first driving device (11), the rotation speed of the second driving device (31), and the flame switch, heat and time of the flame spraying device (2); the first transmission device The rotation speed of the optical fiber (12) is less than or equal to the rotation speed of the second transmission device (32); the sleeve (4) is located at the flame-spraying heating position of the flame-spraying device (2); both sides of the sleeve (4) have openings; the optical fiber to be processed enters the sleeve (4) from the opening on one side of the sleeve (4) and then passes out from the opening on the other side; the sleeve (4) is made of a quartz material with a melting point greater than that of the optical fiber (8); the sleeve (4) is provided with a plurality of micro-holes on at least one side close to the flame-spraying device (2); when the flame-spraying device (2) sprays fire, the outer flame passes through the micro-holes and enters the sleeve, and the sleeve (4) directly contacts the inner flame or the flame core of the flame-spraying device (2).

2. A gradient optical fiber manufacturing system as claimed in claim 1, characterized in that: The gradient optical fiber manufacturing system also includes a fiber coiling device (5) arranged opposite to the drawing device (3), the fiber coiling device (5) includes a third driving device (51) and a fiber coiling wheel (52) driven by the third driving device (51), and the controller is also used to control the rotation speed of the third driving device (51), and the fiber coiling wheel (52) and the second transmission device (32) rotate at the same speed.

3. A gradient optical fiber manufacturing system as claimed in claim 1, characterized in that: The gradient optical fiber manufacturing system also includes a glue coating device (6) arranged between the wire drawing device (3) and the fiber coiling device (5), and the glue coating device (6) includes a glue coating machine (61) and a curing machine (62) arranged between the glue coating machine (61) and the fiber coiling device (5).

4. A gradient optical fiber manufacturing system as claimed in claim 1, characterized in that: The gradient optical fiber manufacturing system also includes a monitoring device (7) arranged between the flame spraying device (2) and the glue coating device (6), and the monitoring device (7) is used to monitor the diameter of the optical fiber (8) after being stretched by the feeding device (1) and the drawing device (3).

5. A gradient optical fiber manufacturing system as claimed in claim 1, characterized in that: The first transmission device (12) is provided with a first optical fiber groove (121) for clamping the optical fiber (8), and the first optical fiber groove (121) is arranged around the first transmission device (12); the feeding device (1) comprises a first auxiliary transmission device (13) arranged opposite to the first transmission device (12), the axis of the first auxiliary transmission device (13) is parallel to the axis of the first transmission device (12), and the first auxiliary transmission device (13) is tangent to the first transmission device (12).

6. A gradient optical fiber manufacturing system as claimed in claim 1, characterized in that: The second transmission device (32) is provided with a second optical fiber groove for clamping the optical fiber (8), and the second optical fiber groove is arranged around the second transmission device (32). The wire drawing device (3) includes a second auxiliary transmission device (33) arranged opposite to the second transmission device (32), the axis of the second auxiliary transmission device (33) is parallel to the axis of the second transmission device (32), and the second auxiliary transmission device (33) is tangent to the second transmission device (32).

7. A method for manufacturing a gradient optical fiber, characterized in that: The gradient optical fiber manufacturing method is applicable to the gradient optical fiber manufacturing system according to any one of claims 1 to 6, and the gradient optical fiber manufacturing method comprises the following steps: S1: Winding the optical fiber: the optical fiber (8) is simultaneously attached to the first transmission device (12) and the second transmission device (32), and the first transmission device (12) and / or the second transmission device (32) are controlled to rotate until the optical fiber (8) is straightened; S2: Drawing optical fiber: The controller controls the flame-spraying device (2) to heat the optical fiber (8), and the controller controls the first transmission device (12) and the second transmission device (32) to rotate at a differential speed to achieve drawing of the optical fiber (8).

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