Anti-resonance hollow-core optical fiber preform positioning mold and assembling method thereof

Abstract

The invention provides an anti-resonance hollow-core optical fiber preform positioning mold and an assembling method thereof, the anti-resonance hollow-core optical fiber preform positioning mold comprises a first group of rod molds, a second group of rod molds and a third group of rod molds, the first group of rod molds are arranged in the central area of a sleeve and are used for forming a fiber core part of an optical fiber; the second group of rod molds are arranged in an anti-resonance area of the cladding and are used for forming a specific structure in the cladding of the optical fiber; the first group of rod molds and the second group of rod molds extend in a conical shape along the longitudinal axis direction of the optical fiber, namely, the outer boundary sizes of the first group of rod molds and the second group of rod molds are gradually changed along the longitudinal axis direction of the optical fiber, so that the first group of rod molds and the second group of rod molds have different cross section sizes at different positions of the optical fiber preform rod. The anti-resonance hollow-core optical fiber preform positioning mold provided by the invention is simple in structure and convenient to assemble and operate, and solves the technical problems of low positioning precision, low manufacturing efficiency, low repeatability and the like of the anti-resonance hollow-core optical fiber preform.

Description

Technical Field

[0001] The invention relates to the technical field of optical fiber preform positioning molds, and in particular to an anti-resonance hollow core optical fiber preform positioning mold and an assembling method thereof. Background Art

[0002] Traditional quartz optical fiber relies on the total internal reflection principle of light to confine light to the solid core for transmission. However, the inherent nonlinearity, dispersion, light damage and other defects of the material limit its application in some special scenarios. Hollow-core optical fiber uses a special cladding structure to confine light to the low-refractive-index air core for transmission, which can fundamentally avoid the intrinsic limitation problem of light in quartz glass or other dielectric materials, and give full play to the application potential of optical fiber in various fields.

[0003] Antiresonant hollow-core optical fiber guides light based on the antiresonant reflective waveguide theory. The high-refractive-index antiresonant thin layer acts as a Fabry-Perot resonant cavity. When the antiresonance condition is met, the light is confined to the low-refractive-index core for transmission. Antiresonant hollow-core optical fiber has the characteristics of low loss, low delay, low dispersion, low nonlinearity, large mode area, wide transmission band, strong gas-light interaction, etc. It has shown great advantages in the fields of optical fiber communication, laser transmission, optical fiber sensing, laser medical treatment, etc.

[0004] The unique advantages of the above antiresonant hollow core optical fiber are due to the ingenious design of its internal microstructure. However, the geometric structure deviation caused during the installation of the antiresonant hollow core optical fiber preform will directly affect the internal geometric structure of the final optical fiber, thereby affecting the optical transmission characteristics of the optical fiber. At present, the "stack-drawing" method is mostly used for antiresonant hollow core optical fiber drawing. When assembling the preform, glass tubes or glass rods with diameters that meet the requirements are often used to support the internal structure of the antiresonant hollow core optical fiber preform, and only the rod assembly glass tubes or glass rods are used in the central area [Reference: Revolver Hollow Core Optical Fibers, Fibers 2018, 6, 39; doi: 10.3390 / fib6020039]. When the size of the filling glass tube or glass rod is large, it is easy to cause the internal glass structure of the antiresonant hollow core optical fiber preform to break during the filling process; when the size of the filling glass tube is small, the internal structure of the antiresonant hollow core optical fiber preform cannot be tightly fixed, which is easy to cause internal structure dislocation. Therefore, traditional antiresonant hollow-core optical fiber preforms have technical problems such as low positioning accuracy, low manufacturing efficiency and poor repeatability.

[0005] The disclosure of the above background technology content is only used to assist in understanding the inventive concept and technical solution of the present invention. It does not necessarily belong to the prior art of this patent application, nor does it necessarily provide technical guidance. In the absence of clear evidence that the above content has been disclosed before the filing date of this patent application, the above background technology should not be used to evaluate the novelty and creativity of the present application. Summary of the invention

[0006] In order to solve the technical problems of low positioning accuracy, low manufacturing efficiency and poor repeatability of traditional anti-resonance hollow-core optical fiber preform, the present invention proposes an anti-resonance hollow-core optical fiber preform positioning mold and an assembly method thereof, which have a simple structure and are easy to operate, and solve the technical problems of low positioning accuracy, low manufacturing efficiency and poor repeatability of anti-resonance hollow-core optical fiber preform.

[0007] In order to achieve the above object, the technical solution of the present invention is as follows:

[0008] The present invention provides an anti-resonance hollow core optical fiber preform positioning mold, comprising:

[0009] A first group of rod dies, the first group of rod dies being arranged in the central area of ​​the sleeve and used for forming a core portion of the optical fiber;

[0010] and / or a second group of rod molds, wherein the second group of rod molds are arranged in the anti-resonance region of the cladding to form a specific structure in the cladding of the optical fiber;

[0011] The first group of rod molds and / or the second group of rod molds both extend in a tapered shape along the longitudinal axis of the optical fiber, that is, along the longitudinal axis of the optical fiber, the outer boundary dimensions of the first group of rod molds and / or the second group of rod molds gradually change, so that they each have different cross-sectional dimensions at different positions on the optical fiber preform.

[0012] The present invention provides an anti-resonance hollow core optical fiber preform positioning mold and an assembly method thereof, which have a simple structure and are easy to operate, and solve the technical problems of low positioning accuracy, low manufacturing efficiency and low repeatability of anti-resonance hollow core optical fiber preform.

[0013] As a preferred technical solution, the variation range of the outer boundary dimensions of the first group of rod molds is designed to cover the outer boundary dimensions of the cladding anti-resonance region;

[0014] The variation range of the outer boundary dimensions of the second group of rod molds is designed to cover the boundary dimensions of the area enclosed between adjacent layers of anti-resonance tubes;

[0015] The first group of rod molds and / or the second group of rod molds can move along the longitudinal axis of the optical fiber to achieve close fit with the end face of the antiresonant hollow core optical fiber preform.

[0016] As a preferred technical solution, the outer boundary shape of the first group of rod molds is determined according to the outer boundary shape of the cladding anti-resonance region, and the outer boundary shape of the second group of rod molds is determined according to the boundary shape of the region enclosed by adjacent layers of anti-resonance tubes.

[0017] As a preferred technical solution, the outer boundary of the first group of rod molds does not completely cover the area in the sleeve surrounded by the outer boundary of the cladding anti-resonance region, so that at least one gap is formed between the first group of rod molds and the inner wall of the sleeve and / or the outer boundary of the cladding anti-resonance region;

[0018] The outer boundary of each of the second group of rod molds does not completely cover the area enclosed by adjacent layers of anti-resonance tubes, thereby forming at least one gap between adjacent layers of anti-resonance tubes;

[0019] During the preform drawing process, the air pressure is filled through the gap.

[0020] As a preferred technical solution, when the number of cladding anti-resonance tube layers is n, the number of the second group of rod molds is n-1, where n≥1.

[0021] As a preferred technical solution, the cone angles of the first group of rod dies and the second group of rod dies extending along the longitudinal axis of the optical fiber are 0.1° to 3°.

[0022] As a preferred technical solution, the thickness of the first group of rod dies and the second group of rod dies extending along the longitudinal axis of the optical fiber is 5 to 20 mm.

[0023] As a preferred technical solution, the number of the second group of rod molds is ≥3.

[0024] The present invention also provides a method for assembling an antiresonant hollow core optical fiber preform positioning mold, assembling the antiresonant hollow core optical fiber preform positioning mold as described in any one of the above items, comprising the following steps:

[0025] S1, at one end of the sleeve, using a first set of rod molds to place at least one anti-resonance outer tube inside the sleeve;

[0026] S2, at the other end of the sleeve, a first set of rod dies is placed;

[0027] S3 checks and confirms that the azimuth angles of the first set of rod molds used at both ends of the sleeve are consistent to ensure that the positions of the anti-resonance outer tubes at both ends of the sleeve are the same;

[0028] S4, in the anti-resonance outer tube already placed at one end of the sleeve, using a second set of rod molds to place at least one anti-resonance inner tube inside the anti-resonance outer tube;

[0029] S5: placing a second set of rod molds in the anti-resonance outer tube that has been placed at the other end of the sleeve;

[0030] S6 checks and confirms that the azimuth angles of the second set of rod molds used at both ends of the sleeve are consistent, so that the positions of the anti-resonance inner tubes at both ends of the sleeve are the same in their respective anti-resonance outer tubes;

[0031] S7 fixes and connects the connections between the tubes in the anti-resonance hollow core optical fiber preform to form a complete preform structure.

[0032] As a preferred technical solution, the material of the first group of rod molds and / or the second group of rod molds is any one of glass, graphite, and metal;

[0033] When the material of the first group of rod molds and / or the second group of rod molds is glass, at least a portion of the preform is aligned with the first group of rod molds and / or the second group of rod molds along the longitudinal axis of the optical fiber, and the preform is connected to the first group of rod molds and / or the second group of rod molds by welding or bonding at the aligned position, and the welding or bonding position covers at least a portion of the first group of rod molds and / or the second group of rod molds, so that the first group of rod molds and / or the second group of rod molds and the preform form an integrated structure;

[0034] When the material of the first group of rod molds and / or the second group of rod molds is graphite or metal, at least a portion of the preform is aligned with the first group of rod molds and / or the second group of rod molds along the longitudinal axis of the optical fiber, and the preform is fixed by welding or bonding at a position that does not cover the first group of rod molds and / or the second group of rod molds. After the preform is fixed, the first group of rod molds and / or the second group of rod molds are removed from the preform.

[0035] The present invention provides an anti-resonance hollow core optical fiber preform positioning mold and an assembly method thereof, which have the following beneficial effects:

[0036] 1) The anti-resonance hollow core optical fiber preform positioning mold has a simple structure and convenient assembly operation, which solves the technical problems of low positioning accuracy, low manufacturing efficiency and low repeatability of anti-resonance hollow core optical fiber preform;

[0037] 2) By using the first group of rod molds and the second group of rod molds extending in a tapered shape, the internal structure of the optical fiber preform can be more effectively positioned and fixed; the first group of rod molds and the second group of rod molds extending in a tapered shape can also provide more uniform support and positioning, which helps to reduce the breakage problem caused by improper glass tube size during the filling process, and improves the positioning accuracy of the anti-resonance hollow-core optical fiber preform;

[0038] The design of the first set of rod molds and the second set of rod molds extending in a tapered shape can simplify the manufacturing process, because the gradually changing shape of the mold can better control the shape of the optical fiber preform, reduce the manufacturing delay caused by size mismatch, and thus improve the manufacturing efficiency;

[0039] The use of a standardized first set of rod molds and a second set of rod molds extending in a conical shape can ensure that the optical fiber preform rods manufactured each time have the same shape, thereby improving the repeatability of manufacturing; the design of the conical mold can also reduce the manufacturing deviation caused by mold wear or deformation, further enhancing the repeatability of manufacturing.

[0040] 3) The outer boundary dimensions of the first group of rod molds are designed to cover the outer boundary dimensions of the cladding anti-resonance region, which ensures that the optical fiber core portion can be accurately formed; the outer boundary dimensions of the second group of rod molds are designed to cover the boundary dimensions of the region enclosed between adjacent layers of anti-resonance tubes, which helps to maintain the stability and consistency of the internal structure of the cladding;

[0041] Since the first group of rod molds and / or the second group of rod molds can move along the longitudinal axis of the optical fiber, they can achieve a tight fit with the end face of the antiresonant hollow core optical fiber preform; this tight fit reduces the positioning error caused by the gap between the mold and the preform; the tight fit also helps to reduce the friction and wear caused by the relative movement between the mold and the preform during the drawing process, thereby improving the quality of the optical fiber.

[0042] 4) By matching the outer boundary shape of the first set of rod molds with the outer boundary shape of the cladding antiresonance region, the outer boundary shape of the optical fiber core portion can be ensured; such precise outer boundary shape helps to reduce positioning errors caused by shape mismatch, thereby improving the manufacturing accuracy of the optical fiber preform;

[0043] Similarly, the outer boundary shape of the second set of rod molds matches the boundary shape of the area enclosed by the adjacent layers of anti-resonance tubes, which can ensure the stability and consistency of the internal structure of the cladding; this matching helps to reduce the structural deviation caused by shape differences, thereby improving the overall performance of the optical fiber preform;

[0044] Precise mold shape can ensure that the optical fiber preform maintains a stable shape and size during the drawing process, thereby optimizing the optical transmission characteristics of the optical fiber; for example, by precisely controlling the mold shape, the transmission loss of light in the optical fiber can be reduced, the axial consistency can be improved, and the transmission efficiency and bandwidth of the optical fiber can be improved.

[0045] 5) The outer boundary of the first group of rod molds does not completely cover the area surrounded by the outer boundary of the cladding anti-resonance region in the sleeve, thereby forming at least one gap between the first group of rod molds and the inner wall of the sleeve and / or the outer boundary of the cladding anti-resonance region; the outer boundary of each of the second group of rod molds does not completely cover the area surrounded by adjacent layers of anti-resonance tubes, thereby forming at least one gap between adjacent layers of anti-resonance tubes, and the gaps are filled with air pressure during the preform drawing process. The air pressure can provide a uniform supporting force, which helps to maintain the structural stability of the optical fiber during the drawing process; especially in a high-temperature drawing environment, the supporting effect of the air pressure can prevent the optical fiber from collapsing due to surface tension; by optimizing the size and distribution of the air pressure, the optical performance of the optical fiber can be further improved, such as reducing light loss and improving transmission efficiency; in an anti-resonance hollow-core optical fiber with a multi-layer structure, the filling of the air pressure helps to maintain the relative position and structural stability between the layers; it can prevent the deformation of the internal structures during the drawing process, thereby ensuring the axial structural consistency of the optical fiber. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 It is a schematic diagram of the cross-sectional structure of one end of the anti-resonance hollow core optical fiber preform of the present invention after being installed through the anti-resonance hollow core optical fiber preform positioning mold;

[0047] Figure 2 It is a schematic diagram of the side structure of the anti-resonance hollow core optical fiber preform after one end of the anti-resonance hollow core optical fiber preform is installed through the anti-resonance hollow core optical fiber preform positioning mold of the present invention;

[0048] Figure 3 A schematic diagram of the cross-sectional structure of the first set of rod molds provided by the present invention;

[0049] Figure 4 A schematic diagram of the side structure of the first set of rod molds provided by the present invention;

[0050] Figure 5 A schematic diagram of the cross-sectional structure of a second set of rod molds provided by the present invention;

[0051] Figure 6 A schematic side structural diagram of a second set of rod molds provided by the present invention;

[0052] Figure 7 The present invention provides a process flow chart of an assembly method of an anti-resonance hollow core optical fiber preform positioning mold.

[0053] Wherein: 1-antiresonance hollow core optical fiber preform; 11-sleeve; 121-antiresonance inner tube; 122-antiresonance outer tube; 2-antiresonance hollow core optical fiber preform positioning mold; 21-first group of rod molds; 22-second group of rod molds. DETAILED DESCRIPTION

[0054] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0055] like Figure 1-2 As shown, the present invention provides an anti-resonance hollow core optical fiber preform positioning mold, comprising:

[0056] A first group of rod molds 21, which are arranged in the central area of ​​the sleeve 11 and are used to form the core part of the optical fiber;

[0057] and / or a second group of rod molds 22, wherein the second group of rod molds 22 is arranged in the anti-resonance region of the cladding to form a specific structure in the cladding of the optical fiber;

[0058] The first group of rod molds 21 and / or the second group of rod molds 22 both extend in a tapered shape along the longitudinal axis of the optical fiber, that is, along the longitudinal axis of the optical fiber, the outer boundary dimensions of the first group of rod molds 21 and / or the second group of rod molds 22 gradually change, so that they each have different cross-sectional dimensions at different positions on the optical fiber preform.

[0059] The present invention provides an anti-resonance hollow core optical fiber preform positioning mold and an assembly method thereof, which have a simple structure and are easy to operate, and solve the technical problems of low positioning accuracy, low manufacturing efficiency and low repeatability of anti-resonance hollow core optical fiber preform.

[0060] By using the first group of rod molds 21 and the second group of rod molds 22 extending in a conical shape, the internal structure of the optical fiber preform can be more effectively positioned and fixed; the first group of rod molds 21 and the second group of rod molds 22 extending in a conical shape can also provide more uniform support and positioning, which helps to reduce the breakage problem caused by improper glass tube size during the filling process, and improves the positioning accuracy of the anti-resonance hollow-core optical fiber preform;

[0061] The design of the first group of rod molds 21 and the second group of rod molds 22 extending in a tapered shape can simplify the manufacturing process, because the gradually changing shape of the mold can better control the shape of the optical fiber preform, reduce the manufacturing delay caused by size mismatch, and thus improve the manufacturing efficiency;

[0062] The use of a standardized first set of rod molds 21 and a second set of rod molds 22 extending in a conical shape can ensure that the optical fiber preforms manufactured each time have the same shape, thereby improving the repeatability of manufacturing; the design of the conical mold can also reduce manufacturing deviations caused by mold wear or deformation, further enhancing the repeatability of manufacturing.

[0063] Preferably, if Figure 1 As shown, the variation range of the outer boundary dimension of the first group of rod molds 21 is designed to cover the outer boundary dimension of the cladding anti-resonance region;

[0064] The variation range of the outer boundary dimensions of the second group of rod molds 22 is designed to cover the boundary dimensions of the area enclosed between adjacent layers of anti-resonance tubes;

[0065] The first group of rod molds 21 and / or the second group of rod molds 22 can move along the longitudinal axis of the optical fiber to achieve a close fit with the end face of the antiresonant hollow core optical fiber preform.

[0066] The outer boundary size of the first group of rod molds 21 is designed to cover the outer boundary size of the cladding anti-resonance region, which ensures that the optical fiber core part can be accurately formed; the outer boundary size of the second group of rod molds 22 is designed to cover the boundary size of the area enclosed by adjacent layers of anti-resonance tubes, which helps to maintain the stability and consistency of the internal structure of the cladding;

[0067] Since the first group of rod molds 21 and / or the second group of rod molds 22 can move along the longitudinal axis of the optical fiber, they can achieve a tight fit with the end face of the antiresonant hollow core optical fiber preform 1; this tight fit reduces the positioning error caused by the gap between the mold and the preform; the tight fit also helps to reduce the friction and wear caused by the relative movement between the mold and the preform during the drawing process, thereby improving the quality of the optical fiber.

[0068] Preferably, if Figure 3 As shown, the outer boundary shape of the first group of rod molds 21 is determined according to the outer boundary shape of the cladding anti-resonance region, and the shape of the first group of rod molds 21 is preferably star-shaped; as shown Figure 4 As shown, the side structure of the first group of rod molds 21 changes in a conical shape along the longitudinal axis of the optical fiber;

[0069] like Figure 5 As shown, the outer boundary shape of the second group of rod molds 22 is determined according to the boundary shape of the region enclosed between adjacent layers of anti-resonance tubes, and the shape of the second group of rod molds 22 is preferably crescent-shaped; as shown Figure 6 As shown, the side structure of the second group of rod molds 22 changes in a conical shape along the longitudinal axis of the optical fiber;

[0070] By matching the outer boundary shape of the first group of rod molds 21 with the outer boundary shape of the cladding anti-resonance region, the outer boundary shape of the optical fiber core portion can be ensured; such precise outer boundary shape helps to reduce positioning errors caused by shape mismatch, thereby improving the manufacturing accuracy of the optical fiber preform;

[0071] Similarly, the outer boundary shape of the second group of rod molds 22 matches the boundary shape of the region enclosed between adjacent layers of anti-resonance tubes, which can ensure the stability and consistency of the internal structure of the cladding; this matching helps to reduce the structural deviation caused by shape differences, thereby improving the overall performance of the optical fiber preform;

[0072] Precise mold shape can ensure that the optical fiber preform maintains a stable shape and size during the drawing process, thereby optimizing the optical transmission characteristics of the optical fiber; for example, by precisely controlling the mold shape, the transmission loss of light in the optical fiber can be reduced, the axial consistency can be improved, and the transmission efficiency and bandwidth of the optical fiber can be improved.

[0073] Preferably, the outer boundary of the first group of rod molds 21 does not completely cover the area in the sleeve 11 surrounded by the outer boundary of the cladding anti-resonance region, so that at least one gap is formed between the first group of rod molds 21 and the inner wall of the sleeve 11 and / or the outer boundary of the cladding anti-resonance region;

[0074] The outer boundary of each of the second group of rod molds 22 does not completely cover the area enclosed by adjacent layers of anti-resonance tubes, thereby forming at least one gap between adjacent layers of anti-resonance tubes;

[0075] Filling the gap with gas pressure during preform drawing;

[0076] The outer boundary of the first group of rod molds 21 does not completely cover the area surrounded by the outer boundary of the cladding anti-resonance region in the sleeve 11, thereby forming at least one gap between the first group of rod molds 21 and the inner wall of the sleeve 11 and / or the outer boundary of the cladding anti-resonance region; the outer boundary of each of the second group of rod molds 22 does not completely cover the area surrounded by adjacent layers of anti-resonance tubes, thereby forming at least one gap between adjacent layers of anti-resonance tubes, and the gaps are filled with air pressure during the preform drawing process. The air pressure can provide a uniform supporting force, which helps to maintain the structural stability of the optical fiber during the drawing process; especially in a high-temperature drawing environment, the supporting effect of the air pressure can prevent the optical fiber from collapsing due to surface tension; by optimizing the size and distribution of the air pressure, the optical performance of the optical fiber can be further improved, such as reducing light loss and improving transmission efficiency; in an anti-resonance hollow-core optical fiber with a multi-layer structure, the filling of the air pressure helps to maintain the relative position and structural stability between the layers; it can prevent the deformation of the internal structures during the drawing process, thereby ensuring the axial structural consistency of the optical fiber.

[0077] Preferably, when the number of cladding antiresonance tube layers is n, the number of the second group of rod molds 22 is n-1, where n≥1. By precisely designing and using n-1 second group of rod molds 22, it is possible to ensure that the cladding structure of the optical fiber preform remains symmetrical in the longitudinal direction, and this symmetry helps to improve the transmission performance and stability of the optical fiber; each mold can precisely control the position and shape of its corresponding antiresonance tube, thereby optimizing the antiresonance effect of the entire cladding, which helps to improve the bandwidth of the optical fiber, reduce optical loss and other performance indicators.

[0078] It should be noted that the above-mentioned embodiment of the present invention only shows a positioning mold for an antiresonant hollow-core optical fiber preform and its assembly method. For the antiresonant hollow-core optical fiber preform with two layers of cladding antiresonant tubes shown in the embodiment, a total of 1 first group of rod molds 21 and 1 second group of rod molds 22 are used. When the cladding antiresonant tube of the antiresonant hollow-core optical fiber preform is a single-layer tube, only the first group of rod molds 21 need to be used. When the cladding antiresonant tube of the antiresonant hollow-core optical fiber preform is a three-layer tube or more, the types of the second group of rod molds 22 need to be increased accordingly. That is, when the number of layers of the cladding antiresonant tube is n, the number of the second group of rod molds 22 is n-1 (n≥1).

[0079] Preferably, the cone angles of the first group of rod dies 21 and the second group of rod dies 22 extending along the longitudinal axis of the optical fiber are in the range of 0.1° to 3°.

[0080] Preferably, the thickness of the first group of rod molds 21 and the second group of rod molds 22 extending along the longitudinal axis of the optical fiber is 5 to 20 mm;

[0081] The thickness of the mold determines the strength of its support for the optical fiber preform; thicker molds can provide stronger support, ensuring that the optical fiber preform remains stable during the preparation and drawing process and is not prone to deformation or bending;

[0082] The thickness of the mold also directly affects its strength. A thicker mold has a higher resistance to deformation and fracture, and can better withstand harsh conditions such as high temperature and high pressure during the preparation process, thereby ensuring the quality of the optical fiber preform.

[0083] Preferably, the number of the second group of rod molds 22 is ≥3; by using multiple second groups of rod molds 22, the position and distribution of the anti-resonance elements in the cladding can be accurately controlled, thereby optimizing the anti-resonance effect; this helps to improve the transmission performance of the optical fiber, such as reducing optical loss, improving transmission efficiency, etc.

[0084] like Figure 7 As shown, the present invention also provides a method for assembling an antiresonant hollow core optical fiber preform positioning mold, assembling the antiresonant hollow core optical fiber preform positioning mold as described in any one of the above items, comprising the following steps:

[0085] S1 A first set of rod molds 21 is placed at one end of the sleeve 11;

[0086] S2: at the other end of the sleeve 11, another anti-resonance outer tube is arranged inside the sleeve using the first set of rod molds 21, and the anti-resonance outer tubes placed at both ends of the sleeve 11 are arranged in positions corresponding to each other in the sleeve 11;

[0087] S3 checks and confirms that the azimuth angles of the first set of rod molds 21 used at both ends of the sleeve 11 are consistent, so as to ensure that the positions of the anti-resonance outer tubes at both ends of the sleeve 11 are the same;

[0088] S4: in the anti-resonance outer tube already placed at one end of the sleeve 11, at least one anti-resonance inner tube is arranged inside the anti-resonance outer tube using a second set of rod molds 22;

[0089] S5: placing a second set of rod molds 22 in the anti-resonance outer tube that has been placed at the other end of the sleeve 11;

[0090] S6 checks and confirms that the azimuth angles of the second set of rod molds 22 used at both ends of the sleeve 11 are consistent, so that the positions of the anti-resonance inner tubes at both ends of the sleeve 11 in their respective anti-resonance outer tubes are the same;

[0091] S7 fixes and connects the connections between the tubes in the anti-resonance hollow core optical fiber preform 1 to form a complete preform structure.

[0092] In steps S1 and S2, the anti-resonance outer tubes are respectively arranged inside the sleeve 11 using the first set of rod molds 21 at both ends of the sleeve 11, and their positions in the sleeve 11 are ensured to correspond. This step provides a basis for subsequent assembly and ensures that the core part of the optical fiber preform has a stable structure;

[0093] In step S3, by checking and confirming that the azimuth angles of the first group of rod molds 21 used at both ends of the sleeve 11 are consistent, it can be ensured that the positions of the anti-resonance outer tubes at both ends of the sleeve 11 are the same. This step ensures the symmetry and consistency of the optical fiber preform in the longitudinal direction, which helps to improve the performance of the optical fiber;

[0094] In step S4 and step S5, the anti-resonance inner tubes are arranged in the anti-resonance outer tubes by using the second set of rod molds 22, and their positions in the respective anti-resonance outer tubes are ensured to be arranged accordingly. This step further increases the complexity of the optical fiber preform and optimizes the anti-resonance effect, thereby improving the transmission performance of the optical fiber.

[0095] In step S6, the azimuth angles of the second group of rod molds 22 used at both ends of the sleeve 11 are checked and confirmed to be consistent, so as to ensure that the anti-resonance inner tubes at both ends of the sleeve 11 are in the same position in their respective anti-resonance outer tubes. This step also ensures the symmetry and consistency of the optical fiber preform in the longitudinal and transverse directions, which helps to improve the stability and reliability of the optical fiber.

[0096] In step S7, by fixing and connecting the connections between the tubes in the antiresonant hollow core optical fiber preform 1, a complete and stable preform structure can be formed, which helps to keep the shape and size of the optical fiber preform unchanged during the subsequent stretching process;

[0097] The stable preform structure can ensure that the optical fiber has better transmission performance and lower loss during the preparation process, and at the same time, it also helps to improve the mechanical strength and durability of the optical fiber;

[0098] Through precise assembly and fixed connection, the preparation process of optical fiber preform can be simplified and errors and losses caused by improper operation can be reduced.

[0099] Preferably, the material of the first group of rod molds 21 and / or the second group of rod molds 22 is any one of glass, graphite, and metal;

[0100] When the material of the first group of rod molds 21 and / or the second group of rod molds 22 is glass, at least a portion of the preform is aligned with the first group of rod molds 21 and / or the second group of rod molds 22 along the longitudinal axis of the optical fiber, and the preform is connected to the first group of rod molds 21 and / or the second group of rod molds 22 by welding or bonding at the aligned position, and the welding or bonding position covers at least a portion of the first group of rod molds 21 and / or the second group of rod molds 22, so that the first group of rod molds 21 and / or the second group of rod molds 22 and the preform form an integrated structure;

[0101] When the material of the first group of rod molds 21 and / or the second group of rod molds 22 is graphite or metal, at least a portion of the preform is aligned with the first group of rod molds 21 and / or the second group of rod molds 22 along the longitudinal axis of the optical fiber, and the preform is fixed by welding or bonding at a position that does not cover the first group of rod molds 21 and / or the second group of rod molds 22. After the preform is fixed, the first group of rod molds 21 and / or the second group of rod molds 22 are removed from the preform;

[0102] The selection of mold materials and the way they are connected to the preform play a crucial role in the preparation of antiresonant hollow-core optical fiber preforms. These selections and designs not only ensure the shape and dimensional accuracy of the optical fiber preform, but also improve its overall quality and transmission performance.

[0103] It is to be understood that the present invention is described by some embodiments, and it is known to those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all various changes or equivalent substitutions falling within the scope of the claims of the present application are included. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of the present application are within the scope protected by the present invention.

Claims

1. An anti-resonant hollow core optical fiber preform positioning mold, characterized in that: include: A first group of rod dies, the first group of rod dies being arranged in the central area of ​​the sleeve and used for forming a core portion of the optical fiber; and / or a second group of rod molds, wherein the second group of rod molds are arranged in the anti-resonance region of the cladding to form a specific structure in the cladding of the optical fiber; The first group of rod molds and / or the second group of rod molds both extend in a tapered shape along the longitudinal axis of the optical fiber, that is, along the longitudinal axis of the optical fiber, the outer boundary dimensions of the first group of rod molds and / or the second group of rod molds gradually change, so that they each have different cross-sectional dimensions at different positions on the optical fiber preform.

2. The anti-resonance hollow core optical fiber preform positioning mold according to claim 1, characterized in that: The variation range of the outer boundary dimensions of the first group of rod molds is designed to cover the outer boundary dimensions of the cladding anti-resonance region; The variation range of the outer boundary dimensions of the second group of rod molds is designed to cover the boundary dimensions of the area enclosed between adjacent layers of anti-resonance tubes; The first group of rod molds and / or the second group of rod molds can move along the longitudinal axis of the optical fiber to achieve close fit with the end face of the antiresonant hollow core optical fiber preform.

3. The anti-resonance hollow core optical fiber preform positioning mold according to claim 1, characterized in that: The outer boundary shape of the first group of rod molds is determined according to the outer boundary shape of the cladding anti-resonance region, and the outer boundary shape of the second group of rod molds is determined according to the boundary shape of the region enclosed by adjacent layers of anti-resonance tubes.

4. The anti-resonance hollow core optical fiber preform positioning mold according to claim 1, characterized in that: The outer boundary of the first group of rod molds does not completely cover the area in the sleeve surrounded by the outer boundary of the cladding anti-resonance region, so that at least one gap is formed between the first group of rod molds and the inner wall of the sleeve and / or the outer boundary of the cladding anti-resonance region; The outer boundary of each of the second group of rod molds does not completely cover the area enclosed by adjacent layers of anti-resonance tubes, thereby forming at least one gap between adjacent layers of anti-resonance tubes; During the preform drawing process, the air pressure is filled through the gap.

5. The anti-resonance hollow core optical fiber preform positioning mold according to claim 1, characterized in that: When the number of cladding anti-resonance tube layers is n, the number of the second group of rod molds is n-1, where n≥1.

6. The anti-resonance hollow core optical fiber preform positioning mold according to claim 1, characterized in that: The cone angles of the first group of rod dies and the second group of rod dies extending along the longitudinal axis of the optical fiber are 0.1° to 3°.

7. The anti-resonance hollow core optical fiber preform positioning mold according to claim 1, characterized in that: The thickness of the first group of rod dies and the second group of rod dies extending along the longitudinal axis of the optical fiber is 5 to 20 mm.

8. The anti-resonance hollow core optical fiber preform positioning mold according to claim 1, characterized in that: The number of the second group of rod molds is ≥3.

9. A method for assembling an anti-resonant hollow core optical fiber preform positioning mold, assembling the anti-resonant hollow core optical fiber preform positioning mold according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1, at one end of the sleeve, using a first set of rod molds to place at least one anti-resonance outer tube inside the sleeve; S2 At the other end of the sleeve, place the first set of rod molds; S3 checks and confirms that the azimuth angles of the first set of rod molds used at both ends of the sleeve are consistent to ensure that the positions of the anti-resonance outer tubes at both ends of the sleeve are the same; S4, in the anti-resonance outer tube already placed at one end of the sleeve, using a second set of rod molds to place at least one anti-resonance inner tube inside the anti-resonance outer tube; S5: placing a second set of rod molds in the anti-resonance outer tube that has been placed at the other end of the sleeve; S6 checks and confirms that the azimuth angles of the second set of rod molds used at both ends of the sleeve are consistent, so that the positions of the anti-resonance inner tubes at both ends of the sleeve are the same in their respective anti-resonance outer tubes; S7 fixes and connects the connections between the tubes in the anti-resonance hollow core optical fiber preform to form a complete preform structure.

10. The method for assembling the anti-resonance hollow core optical fiber preform positioning mold according to claim 9, characterized in that: The material of the first group of rod molds and / or the second group of rod molds is any one of glass, graphite and metal; When the material of the first group of rod molds and / or the second group of rod molds is glass, at least a portion of the preform is aligned with the first group of rod molds and / or the second group of rod molds along the longitudinal axis of the optical fiber, and the preform is connected to the first group of rod molds and / or the second group of rod molds by welding or bonding at the aligned position, and the welding or bonding position covers at least a portion of the first group of rod molds and / or the second group of rod molds, so that the first group of rod molds and / or the second group of rod molds and the preform form an integrated structure; When the material of the first group of rod molds and / or the second group of rod molds is graphite or metal, at least a portion of the preform is aligned with the first group of rod molds and / or the second group of rod molds along the longitudinal axis of the optical fiber, and the preform is fixed by welding or bonding at a position that does not cover the first group of rod molds and / or the second group of rod molds. After the preform is fixed, the first group of rod molds and / or the second group of rod molds are removed from the preform.

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