阅读说明：本技术 一种制备有源光纤的离子溶液掺杂方法及其装置 (Ion solution doping method and device for preparing active optical fiber ) 是由 潘蓉 庞璐 王标 衣永青 沈一泽 武洋 于 2019-11-18 设计创作，主要内容包括：本发明公开了一种制备有源光纤的离子溶液掺杂方法及其装置。将一根内壁沉积有疏松层的石英反应管以竖直的方式固定在装置上,并通过本装置上下往复运动,向石英反应管内多次喷洒离子溶液。本装置采用硬质空心塑料管作为溶液的注入通道,空心塑料管的一端连接溶液储存器,另一端连接喷洒器,本方法采用角度可调、可往复移动式喷洒注入方式对有源光纤进行离子溶液掺杂,由于喷洒器进入反应管中喷洒,反应管各点接触的溶液浓度一样,解决了传统方法出现浸泡预制棒时离子溶液浓度不均的问题,进一步提高了光纤的合格率,由此降低了光纤损耗,提高了光纤激光器的光束质量。(The invention discloses an ionic solution doping method and device for preparing active optical fibers. A quartz reaction tube with a loose layer deposited on the inner wall is fixed on the device in a vertical mode, and ionic solution is sprayed into the quartz reaction tube for multiple times through the up-and-down reciprocating motion of the device. The device adopts a hard hollow plastic pipe as an injection channel of solution, one end of the hollow plastic pipe is connected with a solution storage device, the other end of the hollow plastic pipe is connected with a sprayer, the method adopts an angle-adjustable and reciprocating spraying injection mode to dope the active optical fiber with the ionic solution, the sprayer enters a reaction tube to spray, the concentration of the solution contacted with each point of the reaction tube is the same, the problem that the concentration of the ionic solution is uneven when a preform rod is soaked in the traditional method is solved, the qualification rate of the optical fiber is further improved, the loss of the optical fiber is reduced, and the beam quality of the optical fiber laser is improved.)

1. The ion solution doping method for preparing the active optical fiber is characterized in that an angle-adjustable and reciprocating spraying injection device is adopted to dope the active optical fiber with the ion solution, and the method comprises the following steps:

(1) a quartz tube is used as a reaction tube for deposition, and loose layer deposition is carried out on the inner wall of the reaction tube on a rod-making lathe, wherein the loose layer is used for adsorbing solute ions in a solution;

(2) taking down the reaction tube deposited with the loose layer and the supporting tube connected with the reaction tube from the bar making lathe together, and introducing high-purity inert protective gas into the reaction tube when taking down;

(3) fixing the reaction tube and the supporting tube on a chuck of a machine tool, clamping the chuck at the middle position of the supporting tube, and rotating the chuck at any angle so as to adjust the placing angle of the reaction tube;

(4) one end of a hollow plastic pipe fixed on the electric lifting platform is connected with the sprayer and vertically extends into the lowest end of the reaction pipe along the axial direction of the supporting pipe, namely the initial position of the sprayer, the other end of the hollow plastic pipe is connected with a guide pipe, and the guide pipe is connected with a solution outlet fixed in the ionic solution storage;

(5) starting a motor driving device on the electric lifting platform, driving a transmission device on the electric lifting platform by the motor driving device, enabling the sprayer to move in the reaction tube along the axial direction at a constant speed, and simultaneously opening a pipeline switch between the ionic solution storage device and the guide tube, so that the ionic solution reaches the guide tube through the solution outlet and is sprayed to the surface of the loose layer by the sprayer;

(6) when the sprayer reaches a designated position or an extreme position, a pipeline switch between the ionic solution storage and the guide pipe is closed, the sprayer stops spraying the ionic solution, or the motor driving device drives an electric lifting platform on the guide rail to drive the hollow plastic pipe and the sprayer to move reversely in the axial direction in the reaction pipe, and repeated spraying is carried out;

(7) when the solution spraying is finished, the motor driving device drives the sprayer to leave the reaction tube, the motor driving device stops driving, the motor driving device is closed, a chuck of the machine tool is loosened, the supporting tube and the reaction tube are taken down, and the supporting tube and the reaction tube are installed on a bar making lathe for standing and drying; and finishing the doping of the ionic solution.

2. The method of claim 1, wherein the flow rate of the ion solution sprayed by the sprayer is controlled to be 1ml/s to 10 ml/s.

3. The method of claim 2, wherein the step speed of the sprayer is controlled in the range of 1mm/s to 60 mm/s.

4. The method of claim 3, wherein the sprayer sprays the active optical fiber 1 ~ 10 times.

5. The method of claim 1, wherein in steps (1) and (2), the reaction tube has a length of 600 ± 10mm, and the support tube has a length of 500 ± 10 mm.

6. The ion solution doping method for preparing an active optical fiber according to claim 1, wherein in the step (2), after the deposition of the loose layer in the reaction tube, the inner diameter of the reaction tube is between 18 mm and 19mm, and the inner diameter of the supporting tube is 20 mm.

7. The ion solution doping method for preparing active optical fiber as claimed in claim 1, wherein in the step (4), the length of the hollow plastic tube is 1100-1200mm, the outer diameter is 9-10mm, the inner diameter is 3-4mm, the inner diameter of the conduit is 9mm, the outer diameter of the sprayer is 14-15mm, and the inner diameter is 3-4 mm.

8. A spray injection device used in the ion solution doping method for preparing an active optical fiber according to claim 1, wherein the spray injection device comprises a solution storage (1), a guide pipe (2), a sprayer (3), a hollow plastic pipe (4), a support pipe (5), a reaction pipe (6), an electric lifting table (7) and a guide rail (8); wherein the solution storage device (1) is fixed at the upper end of the frame, one end of the conduit (2) is connected with the upper end of the solution outlet of the solution storage device (1), the other end of the conduit (2) is connected with one end of the hollow plastic pipe (4), the other end of the hollow plastic pipe (4) is provided with the sprayer (3), and then the sprayer passes through a preformed hole on the electric lifting platform (7) and enters the supporting pipe (5) connected with the reaction pipe (6); the hollow plastic pipe (4) is fixed on the electric lifting platform (7) through a baffle (14), the electric lifting platform (7) is seated on the guide rail (8), and the supporting pipe (5) is fixed on a machine tool chuck (9).

9. The ion solution doping method for preparing active optical fiber according to claim 8, wherein the baffle plate (14) and the chuck (9) of the machine tool are always coaxial.

Technical Field

The invention relates to a preparation technology of an optical fiber preform, in particular to an ionic solution doping method and device for preparing active optical fiber.

Background

With the development of laser technology, lasers are more and more widely applied in military and civil affairs, and meanwhile, the requirements for the lasers are higher and higher, and high quality, high power and high efficiency are important standards for judging the quality of the lasers. In recent years, the rare earth ion doped fiber laser has been paid more attention because of its advantages of good beam quality, small volume, fast speed, long working life, etc. And has been widely used in the laser welding field, the medical field, the laser communication and other fields.

The core part of the fiber laser is the rare earth ion doped fiber, and the doping process of doping rare earth ions is divided into two major categories, namely a liquid phase doping method and a gas phase doping method. The liquid phase doping method is to soak the loose layer with ion solution to make the ion in the ion solution absorbed by the loose layer so as to achieve the purpose of doping rare earth ions.

At present liquid phase doping method, there is the doping concentration inequality mainly, two main problems that the isolation layer drops, traditional solution soaks the mode, can not reasonable control ion position in the concentration of each position, solution pours into prefabricated stick back into, the ion diffuses by oneself and gets into loose layer, because the preparation technology problem on loose layer, can lead to in the reaction tube each position on loose layer to the absorption velocity of tombarthite ion different, produce ion concentration inequality, and if soak the time overlength can lead to loose layer structure to be destroyed, lead to loose layer to drop.

Disclosure of Invention

Aiming at the defect that the beam quality of an optical fiber laser is not good due to uneven solution concentration caused by the ion solution soaking injection mode in the traditional method, the invention provides an ion solution doping method and device for preparing an active optical fiber. The invention solves the problems of uneven ion concentration and easy falling of a loose layer by adopting an angle-adjustable and reciprocating ionic solution spraying mode so as to achieve the purposes of improving the absorption uniformity of the optical fiber, reducing the loss of the optical fiber, improving the beam quality of the optical fiber laser and prolonging the service life of the optical fiber.

The technical scheme adopted by the invention for realizing the purpose is as follows: the ion solution doping method for preparing the active optical fiber is characterized in that an angle-adjustable and reciprocating spraying injection device is adopted to dope the active optical fiber with the ion solution, and the method comprises the following steps:

(1) and adopting a quartz tube as a reaction tube for deposition, and depositing a loose layer on the inner wall of the reaction tube on a rod-making lathe, wherein the loose layer is used for adsorbing solute ions in the solution.

(2) And taking down the reaction tube deposited with the loose layer and the supporting tube connected with the reaction tube from the rod making lathe together, and introducing high-purity inert protective gas into the reaction tube when taking down.

(3) The reaction tube and the supporting tube are fixed on a chuck of the machine tool, the chuck is clamped in the middle of the supporting tube, and the chuck rotates at any angle, so that the placing angle of the reaction tube is adjusted.

(4) One end of a hollow plastic pipe fixed on the electric lifting platform is connected with the sprayer and vertically extends into the lowest end of the reaction pipe along the axial direction of the supporting pipe, namely the initial position of the sprayer, the other end of the hollow plastic pipe is connected with a guide pipe, and the guide pipe is connected with a solution outlet fixed in the ionic solution storage device.

(5) And starting a motor driving device on the electric lifting platform, driving a transmission device on the electric lifting platform by the motor driving device, enabling the sprayer to move axially at a constant speed in the reaction tube, and simultaneously opening a pipeline switch between the ionic solution storage device and the guide tube to enable the ionic solution to reach the guide tube through the solution outlet and be sprayed to the surface of the loose layer by the sprayer.

(6) And when the sprayer reaches a designated position or an extreme position, closing a pipeline switch between the ionic solution storage and the guide pipe, stopping spraying the ionic solution by the sprayer, or driving an electric lifting platform on the guide rail by a motor driving device to drive the hollow plastic pipe and the sprayer to move reversely in the axial direction in the reaction pipe, and repeatedly spraying.

(7) When the solution spraying is finished, the motor driving device drives the sprayer to leave the reaction tube, the motor driving device stops driving, the motor driving device is closed, a chuck of the machine tool is loosened, the supporting tube and the reaction tube are taken down, and the supporting tube and the reaction tube are installed on a bar making lathe for standing and drying; and finishing the doping of the ionic solution.

The flow range of the ionic solution sprayed by the sprayer is controlled to be 1ml/s-10 ml/s.

The step speed range of the sprayer is controlled to be 1mm/s-60 mm/s.

The sprayer of the invention performs 1 ~ 10 sprays.

In the steps (1) and (2), the length of the reaction tube is 600 +/-10 mm, and the length of the supporting tube is 500 +/-10 mm.

In the step (2), after the loose layer in the reaction tube is deposited, the inner diameter of the reaction tube is 18 mm-19 mm, and the inner diameter of the supporting tube is 20 mm.

In the step (4), the length of the hollow plastic pipe is 1100-1200mm, the outer diameter is 9-10mm, the inner diameter is 3-4mm, the inner diameter of the conduit is 9mm, the outer diameter of the sprayer is 14-15mm, and the inner diameter is 3-4 mm.

The invention relates to a spraying injection device adopted by an ionic solution doping method for preparing active optical fibers, which is characterized by comprising a solution storage, a guide pipe, a sprayer, a hollow plastic pipe, a supporting pipe, a reaction pipe, an electric lifting table and a guide rail; the solution storage device is fixed at the upper end of the frame, one end of the guide pipe is connected to the upper end of the solution outlet of the solution storage device, the other end of the guide pipe is connected with one end of a hollow plastic pipe, the other end of the hollow plastic pipe is provided with a sprayer, and then the sprayer penetrates through a preformed hole in the electric lifting platform to enter a supporting pipe connected with the reaction pipe; the hollow plastic pipe is fixed on the electric lifting platform through the retaining sheet, the electric lifting platform is seated on the guide rail, and the supporting pipe is fixed on a machine tool chuck.

The beneficial effects produced by the invention are as follows: the method adopts a vertical and reciprocating spraying injection mode to dope the ion solution for the active optical fiber, and because the sprayer enters the reaction tube to spray, the concentration of the solution contacted with each point of the reaction tube is the same, thereby solving the problem of uneven concentration of the ion solution when the prefabricated rod is soaked in the traditional method, further improving the qualification rate of the optical fiber, reducing the loss of the optical fiber and improving the beam quality of the optical fiber laser. And the solution flow rate or the step speed of the sprayer can be controlled so as to control the doping ion concentration of the optical fiber preform, thereby meeting the use requirements of various aspects.

Drawings

FIG. 1 is a schematic structural view of a spray injector used in an embodiment of the present invention;

FIG. 2 is a schematic view of a structure of a baffle plate and a chuck in an embodiment of the present invention;

fig. 3 is a cross-sectional view of a doped optical fiber preform fabricated using the present invention.

Detailed Description

The invention is further illustrated by the following examples in conjunction with the accompanying drawings:

referring to fig. 1, this embodiment takes a manufacturing process of a more common ytterbium-doped optical fiber preform as an example, and includes the following steps:

(1) and a quartz tube is used as the reaction tube 6 for deposition, and an isolation layer is deposited on the inner wall of the reaction tube 6 and used for preventing impurity ions in the reaction tube 6 from entering the core layer.

(2) And then depositing a loose layer on the reaction tube 6 deposited with the isolation layer to obtain the reaction tube 6 to be doped and connected with the supporting tube, wherein the loose layer is an unsintered, opaque and porous deposition layer and is used for adsorbing solute ions in the solution. The loose layer is located in the reaction tube 6, and after the deposition process, a monolithic quartz reaction tube is obtained in which the support tube 5 is connected to the reaction tube 6, thanks to known processes.

(3) Fixing a supporting tube 5 to be doped and connected with a reaction tube 6 on a chuck 9 of a machine tool, connecting one end of a hollow plastic tube 4 fixed on an electric lifting table 7 with a sprayer 3, then axially inserting along the supporting tube 5, inserting the sprayer 3 to the lowest end of the reaction tube 6, namely the initial position of the sprayer 3, connecting the other end of the hollow plastic tube 4 with a conduit 2, and connecting the conduit 2 with a solution outlet fixed in an ionic solution storage 1.

(4) And starting the electric lifting platform 7, wherein the electric lifting platform 7 drives the sprayer 3 at the top end of the hollow plastic tube 4 to move axially to enter the reaction tube 6, and simultaneously, the nitrogen inlet switch is opened, the pipeline switch between the ionic solution storage device 1 and the guide tube 2 is opened, so that the ionic solution enters the guide tube 2 through the solution outlet and reaches the sprayer 3 at the top end to be sprayed out.

(5) When the sprayer 3 reaches a designated position or a limit position, a pipeline switch between the ionic solution storage device 1 and the guide pipe 2 is closed, a nitrogen inlet switch is closed, the sprayer 3 stops spraying the ionic solution, and the motor driving device drives the electric lifting platform 7 on the guide rail 8 to drive the hollow plastic pipe 4 and the sprayer 3 to move in the reverse axial direction and leave the reaction pipe 6; until the sprinkler 3 returns to the initial position, the motor driving means stops driving.

(6) Closing the motor driving device, loosening the chuck 9 of the machine tool, taking down the supporting tube 5 and the reaction tube 6, mounting the supporting tube and the reaction tube on a bar-making lathe, standing and drying; and finishing the doping of the ionic solution.

A quartz reaction tube with a loose layer deposited on the inner wall is fixed on the device in a vertical mode, and ionic solution is sprayed into the quartz reaction tube for multiple times through the up-and-down reciprocating motion of the device. The spraying injection device adopts a hard hollow plastic pipe as an injection channel of the solution, one end of the hollow plastic pipe is connected with a solution storage device, the other end of the hollow plastic pipe is connected with a sprayer, the solution storage device is used for controlling the pressure of the solution and conveying the solution at a constant speed, and the side surface of the sprayer comprises at least one pore or slit, so that the solution flowing out at the constant speed forms one or more spraying surfaces. The electric lifting platform for fixing the reaction tube can drive the spraying device to axially reciprocate along the axial direction. The baffle plate for fixing the hollow plastic pipe and the chuck for fixing the support pipe are kept coaxial (as shown in figure 2), and when the chuck is rotated, the sprinkler and the reaction pipe can synchronously rotate, so that the placing angle of the reaction pipe can be randomly adjusted.

In this example, the length of the reaction tube 6 is about 600mm, and the high-purity inert protective gas is kept flowing through the reaction tube. The selected support tube 5 has a length of about 500 mm.

The thickness of the inner wall of the reaction tube 6 in this example is about 18.5mm, and the inner diameter of the support tube 5 is 20 mm; the reaction tube 6 has a small degree of bending after deposition of the porous layer so that the hollow plastic tube 4 and the sprinkler 3 can be introduced into the reaction tube.

In the present embodiment, the length of the selected hollow plastic tube 4 is about 1150mm, the outer diameter is about 9.5 mm, the inner diameter is about 3.5mm, the outer diameter of the sprinkler 3 is about 14.5mm, and the inner diameter is about 3.5 mm. The outer diameter of the guide pipe 2 is not required, the length requirement is related to the actual instrument placing position, and the guide pipe in the whole working engineering is ensured not to be pulled.

The hollow plastic tube 4 and the sprayer 3 in the step (3) of this example were cleaned with deionized water.

The flow control of this embodiment ionic solution is 5ml/s, and the miniflow is controlled as far as possible, avoids solution and loose layer to produce too big interact, leads to loose layer structure to be destroyed, and loose layer drops.

The present embodiment sets the step speed to 30 mm/s.

In step (5) of this embodiment, when the ion solution is injected, a small amount of liquid remains in the pipeline, and the pipeline needs to be cleaned up by purging, so as to avoid contamination or pipeline blockage.

In the step (6) of this embodiment, the ion solution is absorbed by the porous layer and the porous layer should be prevented from falling off, so the soaking time is not suitable to be too long.

Referring to fig. 1, the spray injection device employed in the embodiment includes a solution storage 1, a guide pipe 2, a sprayer 3, a hollow plastic pipe 4, a support pipe 5, a reaction pipe 6, an electric lift table 7, and a guide rail 8; wherein the solution storage 1 is fixed at the upper end of the frame, one end of the conduit 2 is connected with the upper end of the solution outlet of the solution storage 1, the other end of the conduit 2 is connected with one end of a hollow plastic tube 4, the other end of the hollow plastic tube 4 is provided with a sprayer 3, and then the sprayer passes through a preformed hole on an electric lifting platform 7 and enters a supporting tube 5 connected with the reaction tube 6; the hollow plastic tube 4 is fixed on the electric lifting platform 7 through a baffle plate 14, and the supporting tube 5 is clamped or loosened through a chuck 9 of the machine tool.

The working principle of the spraying and injecting device is as follows: the electric lifting platform 7 and the hollow plastic pipe 4 are connected in a mode of interference fit of a hole and a shaft, namely the electric lifting platform 7 is provided with a hole with a vertical direction, the hollow plastic pipe 4 is inserted and fixed, and the electric lifting platform 7 and the hollow plastic pipe 4 are connected into a whole. The electric lifting platform 7 is provided with a motor driving device, and the motor driving device drives the electric lifting platform 7 to move up and down on the guide rail 8 along the vertical direction to enter or leave the reaction tube 6. The baffle plate 14 is made in the horizontal direction, so that the electric lifting platform 7 can not move in the horizontal direction and is always kept at the center of the supporting pipe without touching the supporting pipe. Meanwhile, the position information of the sprinkler 3 is obtained by receiving the speed sensor on the electric lifting platform in real time and calculating.

The conduit 2 may be made of a material having elasticity such as rubber. The solution outlet connected to one end of the conduit 2 is of stainless steel material, which is welded to the solution reservoir 1. The feeding speed of the ionic solution is controlled by controlling and conveying nitrogen, the nitrogen enters the solution storage 1, the liquid level of the ionic solution is pressed to be low under the action of pressure, and the solution flows out of the solution outlet and enters the pipeline.

When the spraying and injecting device is initially in a vertical state, the electric lifting table 7 is adjusted to enable the top end of the sprayer 3 to be positioned above a chuck 9 of a machine tool, so that the installation of the supporting pipe 5 is facilitated; the obtained support tube 5 was fixed by a machine chuck 9 so that the reaction tube 6 was perpendicular to the ground. The reaction tube 6 is vertically arranged, and the excessive solution which is not absorbed by the loose layer in the reaction tube 6 instantly flows out of the reaction tube under the action of gravity.

The structure of the preform rod prepared by the present invention is shown in fig. 3, and the structure comprises a quartz reaction tube wall 10, an isolation layer 11, a core layer 12 and a hollow part 13.

The manufacturing process of the optical fiber preform doped with other rare earth ions and the optical fiber preform doped with other co-doped ions can refer to the above embodiment, and corresponding ion solution conveying pipelines, gas valves, flowmeters and the like need to be added, and other operations are the same as the above embodiment.