CN-119612952-B - Preparation method of photonic crystal fiber

CN119612952BCN 119612952 BCN119612952 BCN 119612952BCN-119612952-B

Abstract

The invention relates to the technical field of optical fiber preparation, and provides a preparation method of a photonic crystal optical fiber, which comprises the steps of preparing capillary rods, outer sleeves, tail pipes and capillaries with at least one specification, wherein the number of the tail pipes is the same as that of the capillaries; the method comprises the steps of stacking a capillary rod, an outer sleeve and at least one type of capillary tube to obtain a prefabricated rod, ensuring that one end of the prefabricated rod is flush, carrying out tail pipe connection operation on one end of the prefabricated rod, which is not flush, carrying out wire drawing treatment on the prefabricated rod, providing a first negative pressure for the outer sleeve, providing a first positive pressure for the tail pipe, and adjusting the magnitudes of the first positive pressure and the first negative pressure to obtain the photonic crystal fiber, wherein the first positive pressure comprises at least one pressure value, and the number of the pressure values is the same as that of the tail pipes. According to the preparation method of the photonic crystal fiber, the prefabricated rod is controlled in a coordinated and regional mode through different pressure controls, and the purpose of high-precision controllability of the end face structure of the photonic crystal fiber is achieved.

Inventors

Wan Shuangqin
BAO JIANHUA
WANG JING
ZHOU CHENGLI
WANG ZHAO
WANG DAOLONG
YAN DAPENG

Assignees

武汉睿芯特种光纤有限责任公司

Dates

Publication Date: 20260505
Application Date: 20241129

Claims (10)

1. The preparation method of the photonic crystal fiber is characterized by comprising the following steps: Preparing capillary rods, an outer sleeve, tail pipes and at least one specification of capillary, wherein the number of the tail pipes is the same as that of the capillary; stacking the capillary rod, the outer sleeve and the at least one type of capillary tube to obtain a preform rod, and ensuring that one end of the preform rod is flush; performing tail pipe connection operation on the end, which is not flush with the preform rod, of the same specification, so as to ensure that the capillaries with the same specification extend into the same tail pipe; Drawing the preform rod, providing a first negative pressure for the outer sleeve, providing a first positive pressure for the tail pipe, and adjusting the first positive pressure and the first negative pressure to obtain a photonic crystal fiber; Wherein the first positive pressure comprises at least one pressure value, the number of the pressure values being the same as the number of the tail pipes.
2. The method of claim 1, wherein the step of preparing the capillary rod, the outer jacket tube, the tail tube, and the at least one type of capillary tube comprises: Preparing a fiber core capillary rod and a plurality of filling capillary rods with different outer diameters; Preparing one outer sleeve; preparing a plurality of capillaries and preparing tail pipes with the same number as the specifications of the capillaries; The outer diameters of the capillaries with different specifications are the same and the inner diameters are different, and the outer diameters of the capillaries with different specifications are the same as the outer diameters of the fiber core capillary rods.
3. The method of manufacturing a photonic crystal fiber according to claim 1, wherein the step of stacking the capillary rod, the outer jacket tube, and the at least one type of capillary tube to obtain a preform comprises: Compactly stacking the capillary rod and the capillary tube to obtain a preformed piece, wherein the cross section of the preformed piece is in a regular polygon; Loading the preform into the outer sleeve, ensuring that the preform is coaxially disposed with the outer sleeve; a gap between the outer wall of the preform and the inner wall of the outer sleeve fills the capillary rod.
4. The method according to claim 1, wherein the step of performing a tailpipe connection operation on the non-flush end of the preform in the case that the number of the capillary is 1, comprises: Connecting the tail pipe with the preform; and (3) performing heating treatment on the joint of the outer sleeve and the tail pipe, providing a second negative pressure for the outer sleeve, providing a second positive pressure for the tail pipe, and adjusting the second negative pressure and the second positive pressure so as to enable the joint of the outer sleeve and the tail pipe to be fused.
5. The method of claim 4, wherein the tail pipe is butt-jointed with the outer sleeve, and the outer sleeve and the tail pipe are respectively provided with a corresponding pressure channel, and the pressure channels are used for being connected with a corresponding ground pressure source.
6. The method for preparing a photonic crystal fiber according to claim 1, wherein, in the case that the number of the capillary tubes is greater than 1, the number of the capillary tubes is N, and the step of performing the tailpipe connection operation on the non-flush end of the preform comprises: connecting a first tail pipe with the preform; heating the joint of the outer sleeve and the first tail pipe, providing a third negative pressure for the outer sleeve, providing a third positive pressure for the first tail pipe, and adjusting the third negative pressure and the third positive pressure to enable the joint of the outer sleeve and the first tail pipe to be fused; Sequentially connecting the remaining N-1 tail pipes to the first tail pipe; And heating the joint of the Nth tail pipe and the N-1 th tail pipe, providing a fourth negative pressure for the Nth tail pipe, providing a fourth positive pressure for the Nth tail pipe, and adjusting the fourth positive pressure and the fourth negative pressure to enable the joint of the Nth tail pipe and the N-1 th tail pipe to be fused.
7. The method for preparing a photonic crystal fiber according to claim 6, wherein lengths and numbers of the first to nth capillaries are different, the number of the first capillaries is the largest, the length is the shortest, the number of the nth capillaries is the smallest, and the length is the longest; the length of the filling capillary rod is the same as that of the first capillary; The Nth tail pipe is sleeve-shaped; The first tail pipe to the N-1 tail pipe are in a cover shape, openings are formed in the bottom ends of the first tail pipe to the N-1 tail pipe, and the openings of the N-1 tail pipe are used for enabling the N capillary to penetrate; The N tail pipe is used for being in butt joint with the bottom surface end of the N-1 tail pipe, and the cover opening end of the N-1 tail pipe is used for being in butt joint with the bottom surface end of the N-2 tail pipe; The outer diameters of the first tail pipe to the Nth tail pipe are the same.
8. The method of claim 7, wherein the outer jacket tube, the first tail tube and the nth tail tube are each provided with a corresponding pressure channel, and the pressure channels are used for being connected with corresponding ground pressure sources.
9. The method of manufacturing a photonic crystal fiber according to claim 6, wherein the step of performing a tailpipe connection operation on the non-flush end of the preform further comprises: and (3) performing sleeve treatment on the joint of the Nth tail pipe and the N-1 th tail pipe.
10. The method of manufacturing a photonic crystal fiber according to claim 1, wherein between the obtaining of the preform and the tail pipe splicing operation of the preform, further comprising: carrying out tapering or tapering treatment on the flush end of the preform; And the step of performing tail pipe connection operation on the preform and wiredrawing treatment on a plurality of preforms, and further comprises the following steps: and drying the preform after the butt joint tail pipe operation.

Description

Preparation method of photonic crystal fiber Technical Field The invention relates to the technical field of optical fiber preparation, in particular to a preparation method of a photonic crystal fiber. Background The photonic crystal fiber (Photonic Crystal Fibers, PCF) is a novel fiber with unique optical properties, and is characterized in that the refractive index distribution at the cross section perpendicular to the longitudinal axis of the photonic crystal fiber has a two-dimensional periodic structure which is unchanged along the longitudinal axis of the fiber, and the photonic crystal fiber has unique and novel physical characteristics, such as characteristics of no cut-off single mode, adjustable dispersion, effective large mode field area and the like, and has very wide application prospects in the fields of biomedical treatment, fine processing, optical fiber communication and the like. The photonic crystal fiber is generally prepared by adopting a stacking-drawing method, namely capillaries with consistent outer diameters are arranged according to a designed geometric shape, a group of stacked capillaries with the geometric shape is transferred into a proper sleeve, and a quartz wire is used for filling and fixing to form a prefabricated rod of the photonic crystal fiber, and then the photonic crystal fiber is prepared at a high temperature by controlling drawing parameters in a drawing process. The size of the air holes of the section of the photonic crystal fiber is in the micron order, the sizes are not necessarily identical, and in the preparation process, the air holes at different positions can deform or collapse to different degrees to damage the structure of the photonic crystal fiber and directly influence the performance of the photonic crystal fiber. Disclosure of Invention The invention provides a preparation method of a photonic crystal fiber, which is used for solving the problem of unstable product quality caused by deformation or collapse of air holes when the photonic crystal fiber is prepared in the prior art. The invention provides a preparation method of a photonic crystal fiber, which comprises the following steps: Preparing capillary rods, an outer sleeve, tail pipes and at least one specification of capillary, wherein the number of the tail pipes is the same as that of the capillary; stacking the capillary rod, the outer sleeve and the at least one type of capillary tube to obtain a preform rod, and ensuring that one end of the preform rod is flush; performing tail pipe connection operation on the end, which is not flush with the preform rod, of the same specification, so as to ensure that the capillaries with the same specification extend into the same tail pipe; Drawing the preform rod, providing a first negative pressure for the outer sleeve, providing a first positive pressure for the tail pipe, and adjusting the first positive pressure and the first negative pressure to obtain a photonic crystal fiber; Wherein the first positive pressure comprises at least one pressure value, the number of the pressure values being the same as the number of the tail pipes. According to the preparation method of the photonic crystal fiber provided by the invention, the steps of preparing the capillary rod, the outer sleeve, the tail pipe and at least one type of capillary tube comprise the following steps: Preparing a fiber core capillary rod and a plurality of filling capillary rods with different outer diameters; Preparing one outer sleeve; preparing a plurality of capillaries and preparing tail pipes with the same number as the specifications of the capillaries; The outer diameters of the capillaries with different specifications are the same and the inner diameters are different, and the outer diameters of the capillaries with different specifications are the same as the outer diameters of the fiber core capillary rods. According to the preparation method of the photonic crystal fiber provided by the invention, the step of stacking the capillary rod, the outer sleeve and the at least one type of capillary tube to obtain the preform comprises the following steps: Compactly stacking the capillary rod and the capillary tube to obtain a preformed piece, wherein the cross section of the preformed piece is in a regular polygon; Loading the preform into the outer sleeve, ensuring that the preform is coaxially disposed with the outer sleeve; a gap between the outer wall of the preform and the inner wall of the outer sleeve fills the capillary rod. According to the preparation method of the photonic crystal fiber provided by the invention, under the condition that the number of the specifications of the capillary tubes is 1, the step of performing tail pipe connection operation on the non-flush end of the preform rod comprises the following steps: Connecting the tail pipe with the preform; and (3) performing heating treatment on the joint of the outer sleeve and the tail pipe, providing a