Optical fiber manufacturing method

Abstract

The invention discloses an optical fiber manufacturing method which comprises the following steps: S1, preparing raw materials, namely selecting quartz glass with the purity of 99.999% or above as a base material, S2, preparing a preform, namely mixing treated quartz glass powder and a dopant in a specially-made mixing container according to an accurate proportion, S3, drawing an optical fiber, and S4, drawing the optical fiber. Mounting the preform on the top of an optical fiber drawing tower, and preheating the preform before drawing; s4, post-treatment: annealing the drawn optical fiber to eliminate residual stress in the optical fiber, and performing surface treatment on the optical fiber, and S5, performance optimization and customization treatment: selecting a rare earth element dopant, and adopting a mixing process combining ultrasonic vibration, rotary stirring and magnetic field constraint to obtain the rare earth element doped optical fiber. According to the invention, highly uniform distribution of a dopant in quartz glass can be realized on a microscopic level, an integrated process of optical fiber drawing and coating is realized by a double-crucible wire drawing technology, and the production efficiency and the coating quality are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of optical fibers, and particularly to a method for manufacturing optical fibers. Background Art

[0002] With the rapid development of information technology, the performance requirements for optical fibers are getting higher and higher. Traditional optical fiber manufacturing methods have limitations in meeting some special application scenarios, such as high-speed large-capacity data transmission, strong electromagnetic interference resistance, and high-sensitivity sensing. For example, it is difficult to precisely control the microstructure of the core and cladding during the manufacturing process of existing optical fibers, resulting in large losses during the transmission of optical signals and insufficient stability in complex environments. Therefore, it is necessary to develop a new optical fiber manufacturing method to overcome the deficiencies of the existing technology and meet the growing demand for high-performance optical fibers. Summary of the Invention

[0003] An object of the present invention is to solve at least one of the technical problems existing in the prior art, and to provide a method for manufacturing optical fibers. By selecting rare earth element oxides and nano metal particles as dopants, and adopting a hybrid process combining ultrasonic vibration, rotary stirring and magnetic field confinement, it is possible to achieve a highly uniform distribution of dopants in quartz glass at the microscopic level, thereby endowing the optical fiber with more excellent optical and electrical properties, enhanced optical signal amplification ability and special electromagnetic shielding performance.

[0004] The double crucible drawing technology realizes the integrated process of optical fiber drawing and coating, improving the production efficiency and coating quality. The combination of annealing treatment and plasma surface treatment can not only eliminate the residual stress inside the optical fiber, improve the mechanical strength, but also improve the smoothness of the optical fiber surface and the coating adhesion, further improving the stability and reliability of the optical fiber in complex environments and extending the service life of the optical fiber.

[0005] The present invention also provides an optical fiber manufacturing method having the above, including the following steps:

[0006] S1. Raw material preparation, select quartz glass with a purity of more than 99.999% as the base material. At the same time, prepare dopants including rare earth element oxides and nano metal particles;

[0007] S2. Preform preparation, mix the treated quartz glass powder and dopants in a special mixing container according to an accurate ratio, and adopt a combination of ultrasonic vibration and rotary stirring to uniformly disperse the dopants in the quartz glass powder. The ultrasonic vibration frequency is 30 kHz, the stirring speed is 600 revolutions per minute, and the mixing time is 2 hours;

[0008] S3. Optical fiber drawing: Install the preform at the top of the optical fiber drawing tower. Before drawing, preheat the preform at a temperature of 800 °C for 40 minutes to reduce internal stress and improve the stability of drawing.

[0009] S4. Post-treatment: Anneal the drawn optical fiber at a temperature of 700 °C for 2.5 hours to eliminate the residual stress inside the optical fiber. Perform surface treatment on the optical fiber using plasma treatment technology to make the surface of the optical fiber smoother and enhance the adhesion between the coating and the optical fiber.

[0010] S5. Performance optimization and customization: According to different application requirements, the optical fiber can be further optimized. For optical fibers that require high-sensitivity sensing performance, graphene quantum dots and organic fluorescent dyes are added during the raw material preparation stage.

[0011] According to an optical fiber manufacturing method provided by the present invention, in the raw material preparation, the quartz glass raw material is finely ground and screened so that its particle size distribution is within a specific range of 1 to 10 microns to ensure uniform mixing and distribution during subsequent melting and forming processes. The rare earth element oxides include erbium oxide and ytterbium oxide, and the nano metal particles include gold nano particles and silver nano particles.

[0012] According to an optical fiber manufacturing method provided by the present invention, in the preform preparation, the mixed raw materials are put into a high-temperature furnace for melting. The furnace temperature is controlled at 1800 to 2200 °C. During the melting process, a magnetic field confinement technology is adopted to make the melt form a specific convection pattern under the action of the magnetic field, further promoting the uniform distribution of the dopant. The magnetic field intensity is 0.5 to 2 Tesla, and the convection pattern is annular convection to ensure the compositional uniformity of the preform in the radial and axial directions. Using a precision mold and drawing process, the melted material is drawn into a preform. During the drawing process, control the drawing speed at 1 to 5 meters per minute, and at the same time, monitor and adjust the diameter of the preform in real time to control the diameter accuracy of the preform within ±0.1 mm.

[0013] According to an optical fiber manufacturing method provided by the present invention, the optical fiber drawing uses a double crucible drawing technology. Place the preform in the main crucible and place a special coating material in the secondary crucible. During the drawing process, control the temperature of the main crucible at 2000 to 2300 °C and the temperature of the secondary crucible at 300 to 500 °C. After the optical fiber is drawn out of the main crucible, it immediately passes through the secondary crucible to uniformly coat the coating material on the surface of the optical fiber. The coating thickness is controlled at 50 to 200 microns.

[0014] According to a fiber optic manufacturing method provided by the present invention, during the fiber drawing process, laser-assisted heating and cooling technologies are introduced. In the fiber stretching area, a high-power laser beam with a power of 500 watts is used to locally heat the fiber to precisely control the microstructure and refractive index distribution of the fiber. After heating, a combination of nitrogen cooling and liquid cooling is adopted to rapidly cool the fiber at a cooling rate of 500 °C per second, thereby fixing the structure and performance of the fiber.

[0015] According to a fiber optic manufacturing method provided by the present invention, in the post-treatment, the power of the plasma treatment is 5 kW and the treatment time is 20 minutes.

[0016] According to a fiber optic manufacturing method provided by the present invention, in the performance optimization and customization process for enhancing the bending resistance of the fiber, after the annealing treatment, the fiber is placed in a special bending mold and subjected to bending shaping treatment at a temperature of 500 °C and a pressure of 30 MPa for a treatment time of 30 to 120 minutes. In this way, the internal structure of the fiber adapts to the bending stress at the microscopic level, effectively reducing the bending loss.

[0017] According to a fiber optic manufacturing method provided by the present invention, in the performance optimization and customization process, during the raw material preparation stage, graphene quantum dots and organic fluorescent dyes are added, which can form special interactions with the fiber matrix, enhancing the fiber's response ability to specific temperature, strain, and chemical substance concentration. After the fiber drawing is completed, through laser-induced technology, micro-nano structures are formed at specific parts of the fiber, further improving the sensitivity and resolution of sensing.

[0018] Compared with the prior art, a fiber optic manufacturing method of the present invention can achieve a highly uniform distribution of dopants in quartz glass at the microscopic level by selecting rare earth element oxides and nano-metal particles as dopants and adopting a hybrid process combining ultrasonic vibration, rotary stirring, and magnetic field confinement, thereby endowing the fiber with more excellent optical and electrical properties, enhanced optical signal amplification ability, and special electromagnetic shielding performance.

[0019] Compared with the prior art, a fiber optic manufacturing method of the present invention realizes the integration process of fiber drawing and coating by the double crucible drawing technology, improving the production efficiency and coating quality. The combination of annealing treatment and plasma surface treatment can not only eliminate the residual stress inside the fiber, improve the mechanical strength, but also improve the smoothness of the fiber surface and the coating adhesion, further enhancing the stability and reliability of the fiber in complex environments and extending the service life of the fiber. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be further described below in conjunction with the drawings and embodiments;

[0021] Figure 1 This is a flowchart of a method for manufacturing an optical fiber according to the present invention. Specific embodiments

[0022] This part will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The function of the drawings is to supplement the description in the text of the specification, enabling people to intuitively and vividly understand each technical feature and the overall technical solution of the present invention. However, it should not be construed as a limitation on the protection scope of the present invention.

[0023] Referring to Figure 1 , in an embodiment of a method for manufacturing an optical fiber according to the present invention, it includes a raw material preparation stage: purchasing high-purity quartz glass raw materials, using a high-precision particle size analyzer to detect and screen their particle sizes to ensure that the particle sizes meet the requirements, and mixing erbium oxide in a proportion of 0.1% to 1% by mass percentage and gold nanoparticles in a proportion of 0.01% to 0.1% by volume percentage with quartz glass powder in a special stainless steel mixing container. Turn on the ultrasonic vibration device, set the frequency to 30 kHz, and at the same time start the rotary stirrer with a rotation speed set to 600 revolutions per minute. The mixing time is 2 hours. During this period, samples are taken for detection of the mixing situation every 30 minutes to ensure uniform dispersion of the dopants.

[0024] Preform preparation stage: Transfer the mixed raw materials to a high-temperature furnace, and gradually raise the furnace temperature to 2000 °C. During the heating process, turn on the magnetic field generating device, adjust the magnetic field strength to 1 tesla to make the melt form a circular convection. Through the observation window and the on-line composition detection device, the uniformity and temperature change of the melt are monitored in real time. After the melt reaches a stable state, install the preform mold under the furnace and perform the drawing operation at a speed of 3 meters per minute. Use a laser interferometer to monitor the diameter of the preform in real time. By adjusting the drawing speed and the mold temperature, the diameter of the preform is stabilized at ±0.1 mm.

[0025] Optical fiber drawing stage: Install the preform at the top of the optical fiber drawing tower, use a resistance heating device to preheat the preform, set the preheating temperature to 1000 °C, and the preheating time to 45 minutes. Pass high-purity argon gas into the main crucible as a protective gas, raise the temperature of the main crucible to 2200 °C, put a fluoropolymer coating material in the secondary crucible, control the temperature of the secondary crucible at 400 °C, and start drawing the optical fiber. The initial drawing speed is set to 3 meters per minute. During the drawing process, turn on a high-power laser beam with a power of 500 watts to locally heat the optical fiber stretching area. The computer control system adjusts the laser power and the heating position according to the preset refractive index distribution model. The heated optical fiber first passes through a nitrogen cooling pipe with a nitrogen flow rate of 10 liters per minute for preliminary cooling, and then enters a coolant cooling tank. The coolant is an ethylene glycol aqueous solution with a temperature of 20 °C for deep cooling, and the cooling speed is controlled at 500 °C per second.

[0026] Post - processing stage: Place the drawn optical fiber into an annealing furnace. The annealing temperature is set at 800 °C and the annealing time is 2 hours. After annealing, send the optical fiber into the plasma processing chamber, turn on the plasma generator, set the power to 5 kilowatts, and the processing time to 20 minutes.

[0027] Performance optimization and customization processing stage: If manufacturing an optical fiber with optimized bending resistance, place the annealed optical fiber in a special bending mold. The mold temperature is set at 500 °C, the pressure is 30 MPa, and the processing time is 60 minutes. Test the bending resistance of the processed optical fiber to ensure that the bending loss is reduced to the expected level.

[0028] For highly sensitive sensing optical fibers, add 0.05% to 0.5% of graphene quantum dots by mass percentage during raw material preparation. After the optical fiber drawing is completed, use a laser micro - machining system to form a micro - cavity structure on the surface of the optical fiber. The laser power is 5 to 20 watts and the processing time is 5 to 30 minutes. Then, test the sensing performance of the optical fiber to verify its high - sensitivity response to physical quantities such as temperature and strain.

[0029] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above - mentioned embodiments. Within the knowledge scope of those of ordinary skill in the art in the said technical field, various changes can be made without departing from the gist of the present invention.

Claims

1. A method for manufacturing an optical fiber, characterized in that: The following steps are involved: S1. Raw materials and equipment: quartz glass with a purity of more than 99.999% is selected as the basic material. At the same time, dopants including rare earth element oxides and nano-metal particles are prepared; S2. Preparation of preform rods: the treated quartz glass powder and dopant are mixed in a special mixing container in a precise ratio, and the dopant is evenly dispersed in the quartz glass powder by combining ultrasonic vibration and rotary stirring. The ultrasonic vibration frequency is 30 kHz, the stirring speed is 600 revolutions per minute, and the mixing time is 2 hours. S3, optical fiber drawing, the preform rod is installed on the top of the optical fiber drawing tower, and the preform rod is preheated before drawing, the preheating temperature is 800℃, and the time is 40 minutes to reduce the internal stress and improve the drawing stability; S4, post-processing, annealing the drawn optical fiber at a temperature of 700°C for 2.5 hours to eliminate the residual stress inside the optical fiber, and surface treatment of the optical fiber using plasma treatment technology to make the optical fiber surface smoother and enhance the adhesion between the coating and the optical fiber; S4, post-processing, annealing the drawn optical fiber. For optical fibers that require high-sensitivity sensing performance, graphene quantum dots and organic fluorescent dyes are added during the raw material preparation stage.

2. The method for manufacturing an optical fiber according to claim 1, characterized in that: In the raw material equipment, the quartz glass raw material is finely ground and screened to make its particle size distribution within a specific range of 1 to 10 microns to ensure uniform mixing and distribution in the subsequent melting and molding processes. The rare earth element oxides include erbium oxide and ytterbium oxide, and the nano metal particles include gold nanoparticles and silver nanoparticles.

3. The method for manufacturing an optical fiber according to claim 1, characterized in that: In the preparation of the preform, the mixed raw materials are placed in a high-temperature furnace for melting, and the furnace temperature is controlled at 1800 to 2200°C. During the melting process, a magnetic field confinement technology is used to form a specific convection pattern of the melt under the action of the magnetic field, further promoting the uniform distribution of the dopant. The magnetic field strength is 0.5 to 2 Tesla, and the convection pattern is annular convection to ensure the uniformity of the composition of the preform in the radial and axial directions. The melted material is drawn into the preform using a precision mold and wire drawing process. During the wire drawing process, the wire drawing speed is controlled at 1 to 5 meters per minute, and the diameter of the preform is monitored and adjusted in real time, so that the diameter accuracy of the preform is controlled at ±0.1 mm.

4. The method for manufacturing an optical fiber according to claim 1, characterized in that: The optical fiber drawing adopts double-crucible drawing technology, a preform rod is placed in the main crucible, and a special coating material is placed in the auxiliary crucible. During the drawing process, the temperature of the main crucible is controlled at 2000 to 2300°C, and the temperature of the auxiliary crucible is controlled at 300 to 500°C. After the optical fiber is drawn out from the main crucible, it immediately passes through the auxiliary crucible so that the coating material is evenly coated on the surface of the optical fiber, and the coating thickness is controlled at 50 to 200 microns.

5. The method for manufacturing an optical fiber according to claim 1, characterized in that: During the optical fiber drawing process, laser-assisted heating and cooling technology is introduced. In the optical fiber stretching area, a high-power laser beam with a power of 500 watts is used to locally heat the optical fiber to accurately control the microstructure and refractive index distribution of the optical fiber. After heating, a combination of nitrogen cooling and liquid cooling is used to quickly cool the optical fiber at a cooling rate of 500°C per second, thereby fixing the structure and performance of the optical fiber.

6. The method for manufacturing an optical fiber according to claim 1, characterized in that: The power of the plasma treatment used in the post-treatment is 5 kilowatts and the treatment time is 20 minutes.

7. The method for manufacturing an optical fiber according to claim 1, characterized in that: In order to enhance the bending resistance of the optical fiber in the performance optimization and customization process, after the annealing treatment, the optical fiber is placed in a special bending mold and subjected to bending shaping treatment at a temperature of 500°C and a pressure of 30 MPa for a period of 30 to 120 minutes. In this way, the internal structure of the optical fiber adapts to the bending stress at the microscopic level, effectively reducing the bending loss.

8. The method for manufacturing an optical fiber according to claim 1, characterized in that: In the performance optimization and customization process, graphene quantum dots and organic fluorescent dyes are added during the raw material preparation stage, which can form special interactions with the optical fiber matrix and enhance the optical fiber's response to specific temperatures, strains, and chemical concentrations. After the optical fiber is drawn, micro-nano structures are formed at specific locations of the optical fiber through laser induction technology, further improving the sensitivity and resolution of the sensor.

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