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CN-121377522-B - Preparation method of optical fiber preform

CN121377522BCN 121377522 BCN121377522 BCN 121377522BCN-121377522-B

Abstract

The application provides a preparation method of an optical fiber preform, which belongs to the technical field of optical fiber preform processing and comprises a reaction tube, a heating device, an air inlet tube, a driving assembly and a controller, wherein an air outlet end of the reaction tube is communicated with a negative pressure source, the heating device is provided with a heating source which moves along the axial direction of the reaction tube, an air inlet end of the air inlet tube is communicated with a gas supplementing source, the air outlet end of the air inlet tube extends into the reaction tube from the air inlet end of the reaction tube and is close to a heating point of the heating source on the reaction tube, the driving assembly is connected with a part of the air inlet tube which is arranged outside the reaction tube, the driving assembly is used for driving the extending end of the air inlet tube to extend and retract along the axial direction of the reaction tube, the controller is in communication connection with the driving assembly and the heating device, and the controller is used for controlling the extending end of the air inlet tube to move synchronously along with the heating source through the driving assembly. The preparation method of the optical fiber preform can realize accurate air supplement to the fusion shrinkage position, is beneficial to accurate control and compression of the fusion shrinkage position, and can improve the roundness of the optical fiber preform.

Inventors

  • XU SHIJIE
  • WANG SUYU
  • SONG JIAXIANG
  • ZHANG JIAQI
  • WANG HUA
  • ZHAO ZHENXUE

Assignees

  • 中国电子科技集团公司第四十六研究所

Dates

Publication Date
20260512
Application Date
20251222

Claims (9)

  1. 1. The preparation method of the optical fiber preform is characterized in that the preparation is carried out by adopting an optical fiber preform shrinking device, and the optical fiber preform shrinking device comprises: the air outlet end of the reaction tube (1) is communicated with a negative pressure source (6); A heating device having a heating source (2) axially movable along the reaction tube (1); The air inlet pipe (3) is communicated with the air supplementing source (7), and the air outlet end extends into the reaction tube (1) from the air inlet end of the reaction tube (1) and is close to a heating point of the heating source (2) on the reaction tube (1); the driving component (4) is connected with the part of the air inlet pipe (3) arranged outside the reaction tube (1), the driving component (4) is used for driving the extending end of the air inlet pipe (3) to axially extend and retract along the reaction tube (1), and A controller in communication with the drive assembly (4) and the heating device; The controller is used for controlling the extending end of the air inlet pipe (3) to synchronously move along with the heating source (2) through the driving component (4), so that the extending end of the air inlet pipe (3) changes along with the movement of the shrinking position; the preparation method comprises the following steps: determining various technological parameters of an optical fiber preform to be processed; the extending end of the air inlet pipe (3) is close to the heating point of the heating source (2); The driving component (4) and the heating device are started, the heating source (2) axially reciprocates along the reaction tube (1), the extending end of the air inlet tube (3) synchronously moves along with the heating source (2) until the inner diameter of the reaction tube (1) after the completion of the melting shrinkage reaches a preset value, and the driving component (4) and the heating device are closed; The relative positions of the extending end of the air inlet pipe (3) and the heating point of the heating source (2) in the axial direction of the reaction tube (1) are adjusted; the heating device is characterized in that the driving component (4) and the heating device are started, the heating source (2) moves from the compaction starting point to the compaction finishing point, the extending end of the air inlet pipe (3) moves synchronously with the heating source (2) until the inner aperture of the reaction pipe (1) of the compaction section is zero, and the driving component (4) and the heating device are closed.
  2. 2. The preparation method of the optical fiber preform according to claim 1, wherein the extending end of the air inlet pipe (3) is provided with a pressure monitoring piece (5), and the controller is in communication connection with the air supplementing source (7) and the pressure monitoring piece (5); Wherein the controller is used for controlling the ventilation quantity of the air supplementing source (7) after receiving the pressure signal of the pressure monitoring piece (5).
  3. 3. The method of manufacturing an optical fiber preform according to claim 1, wherein the extending end of the air intake pipe (3) near the heating point of the heating source (2) on the reaction tube (1) comprises: In the rest melting and shrinking process, the extending end of the air inlet pipe (3) corresponds to the position of the heating point in the axial direction of the reaction pipe (1); in the last smelting and shrinking process, the extending end of the air inlet pipe (3) and the heating point are arranged in a staggered mode in the axial direction of the reaction pipe (1).
  4. 4. The method of manufacturing an optical fiber preform according to claim 1, wherein the air intake pipe (3) comprises: A first connecting pipe (31), the air inlet end of which is communicated with the air supplementing source (7); The middle pipe (32) is communicated with the air outlet end of the first connecting pipe (31), and the middle pipe (32) is a telescopic hose; the gas inlet end of the second connecting pipe (33) is communicated with the gas outlet end of the middle pipe (32), the gas outlet end of the second connecting pipe extends into the reaction pipe (1), and the part of the second connecting pipe (33) arranged outside the reaction pipe (1) is connected with the driving assembly (4).
  5. 5. A method of preparing an optical fiber preform according to claim 1, wherein the drive assembly (4) comprises: a drive motor (41) in communication with the controller; the power output end of the transmission assembly (42) is provided with a degree of freedom for moving along the axial direction of the reaction tube (1); the connecting block (43) is fixed on the part of the air inlet pipe (3) which is arranged outside the reaction pipe (1) and is fixedly connected with the power output end of the transmission assembly (42); The driving motor (41) is used for driving the connecting block (43) to axially stretch along the reaction tube (1) through the transmission assembly (42).
  6. 6. The optical fiber preform manufacturing method according to claim 5, wherein the transmission assembly (42) includes: the rotating screw rod (421) is arranged along the axial extension of the reaction tube (1), and the rotating screw rod (421) is in power connection with the output shaft to form a power input end of the transmission assembly (42); a moving nut (422) screwed on the rotating screw rod (421) and fixedly connected with the connecting block (43); When the driving motor (41) drives the rotating screw (421) to rotate, the moving nut (422) is used for driving the connecting block (43) to move on the rotating screw (421) so as to form a power output end of the transmission assembly (42).
  7. 7. The method of manufacturing according to claim 1, wherein the determining the process parameters of the optical fiber preform to be processed comprises: determining the type of gas supplemented by the supplementing source (7) and the initial ventilation; determining a preset pressure value in the reaction tube (1) during condensation; Determining a shrinking stroke and a lap index of the shrinking process; and determining the moving speed of the heating source (2), and determining the moving speed of the extending end of the air inlet pipe (3).
  8. 8. The preparation method according to claim 7, characterized in that a pressure monitoring element (5) is arranged at the inlet end of the inlet pipe (3) before the preparation method is started; During the shrinking process, the controller is used for adjusting the ventilation quantity of the air supplementing source (7) so as to enable the pressure value monitored by the pressure monitoring piece (5) to reach the preset pressure value.
  9. 9. The preparation method according to claim 1, wherein the heating point of the heating device is aligned with the extending end of the air inlet pipe (3) in the axial direction of the reaction tube (1) by making the extending end of the air inlet pipe (3) close to the heating point of the heating source (2); The relative positions of the extending end of the air inlet pipe (3) and the heating point of the heating source (2) in the axial direction of the reaction tube (1) are specifically that the heating source (2) is arranged at the compaction starting point, the extending end of the air inlet pipe (3) is arranged in the shrinkage stroke and is staggered with the heating point of the heating source (2) by a preset distance, and the preset distance is 20-40mm.

Description

Preparation method of optical fiber preform Technical Field The application belongs to the technical field of optical fiber perform processing, and particularly relates to a preparation method of an optical fiber perform. Background After the optical fiber preform is deposited by MCVD or PCVD, the reaction tube is required to be heated by a heating device, and the heating point of the heating device translates along the direction of the reaction tube, so that the optical fiber preform can be melted and reduced in diameter at high temperature, namely, the optical fiber preform is melted and reduced, and is further compacted after the melting and the reduction are finished until the complete optical fiber preform is formed. In the prior art, when the melting and shrinking process is carried out, air is usually supplemented into the reaction tube through an air supplementing device. Because the reactor tube itself has a certain length, the supplemental gas needs to travel a distance inside the reactor tube to reach the collapsing position. Therefore, gas loss exists between the actual air supplementing quantity of the shrinkage position and the actual air conveying quantity of the air supplementing air inlet pipe, the pressure control of the shrinkage position is not facilitated, and the prepared optical fiber preform is low in roundness and poor in quality. Disclosure of Invention The application aims to provide a preparation method of an optical fiber preform, which aims to solve the technical problem that in the existing preparation of the optical fiber preform, deviation exists between the actual air supplementing quantity in the melting and shrinking process and the actual air conveying quantity of an air supplementing inlet pipe, and the roundness of the optical fiber preform is affected. In order to achieve the above purpose, the application adopts the following technical scheme: in a first aspect, there is provided an optical fiber preform collapsing apparatus comprising: the gas outlet end of the reaction tube is communicated with a negative pressure source; a heating device having a heating source axially movable along the reaction tube; The gas outlet end of the gas inlet pipe extends into the reaction pipe from the gas inlet end of the reaction pipe and is close to a heating point of the heating source on the reaction pipe; the driving assembly is connected with the part of the air inlet pipe which is arranged outside the reaction pipe and used for driving the extending end of the air inlet pipe to extend and retract along the axial direction of the reaction pipe, and A controller in communication with the drive assembly and the heating device; the controller is used for controlling the extending end of the air inlet pipe to synchronously move along with the heating source through the driving assembly, so that the extending end of the air inlet pipe changes along with the movement of the fusing position. Compared with the prior art, the scheme provided by the embodiment of the application has the advantages that the reaction tube is contracted at the heating point of the heating source, and when the heating source moves along the axial direction of the reaction tube, the contracted position is also changed continuously along the axial direction of the reaction tube; When the heating device moves, the controller can control the driving assembly to enable the extending end of the air inlet pipe to synchronously move along with the heating source, so that the air supplementing position changes along with the melting and shrinking position in real time, and further, the accurate air supplementing of the melting and shrinking position is realized, therefore, the actual air supplementing amount at the melting and shrinking position is ensured to be consistent with the preset air supplementing amount, the accurate pressure control of the melting and shrinking position is facilitated, the roundness of the optical fiber perform is improved, and the quality of the optical fiber perform is further improved; therefore, the optical fiber preform shrinking device provided by the application can realize accurate air supply to the shrinking position, is beneficial to realizing pressure control of the shrinking position, improves the roundness of the optical fiber preform, and ensures the product quality. With reference to the first aspect, in a possible implementation manner, the extending end of the air inlet pipe is provided with a pressure monitoring piece, and the controller is in communication connection with the air supplementing source and the pressure monitoring piece; The controller is used for controlling the ventilation volume of the air supplementing source after receiving the pressure signal of the pressure monitoring piece. The pressure monitoring piece is arranged at the extending end of the air inlet pipe, and the extending end of the air inlet pipe can synchronously move along with the heating sou