Method for manufacturing hollow core optical fiber and hollow core optical fiber

Abstract

The present application provides a method for manufacturing a hollow-core optical fiber and a hollow-core optical fiber, and relates to the technical field of communication engineering. The method for manufacturing the hollow-core optical fiber comprises: arranging a plurality of tubular elements on the inner wall of an outer cladding; arranging a supporting element between adjacent tubular elements; arranging a central element coaxially with the outer cladding in the outer cladding, and abutting the central element against the plurality of supporting elements; connecting the outer wall of the central element, the spaces between the plurality of tubular elements and the plurality of supporting elements to form a first connecting area, wherein the interior of the central element is an air-filled area; heating the interior of the outer cladding; separately inflating the air-filled area and the first connecting area, and adjusting the air-filled pressure in the air-filled area and the first connecting area so that the central element deforms toward the center of the outer cladding to form a plurality of first anti-resonance layers arranged at intervals. The method for manufacturing the hollow-core optical fiber of the present application reduces the loss of the hollow-core optical fiber during optical signal transmission.

Description

Technical Field

[0001] The present application relates to the field of communication engineering technology, and in particular to a method for manufacturing a hollow-core optical fiber and a hollow-core optical fiber. Background Art

[0002] Hollow-core antiresonant fiber uses air instead of glass in traditional optical fibers to transmit optical signals. This design helps overcome the problems of nonlinearity, dispersion, light-induced damage and material absorption loss in traditional solid-core optical fibers during transmission. The light-guiding mechanism of hollow-core antiresonant fiber is mainly based on the antiresonance effect, that is, through the cladding structure of the optical fiber, the light waves are coherently destructed at the interface between the air core and the cladding, thereby suppressing the leakage of light waves and achieving effective transmission of optical signals.

[0003] The hollow-core optical fiber of the related technology includes a quartz tube and multiple cladding structures. The multiple cladding structures are evenly distributed along the circumference of the inner wall of the quartz tube. The center position of the multiple cladding structures is an air core. When arranging the multiple cladding structures, it is necessary to maintain that there are no structural intersections or connection points between the multiple cladding structures. Each cladding structure is an independent unit. The cladding structure of some hollow-core optical fibers adopts a multi-layer nested structure. The multi-layer nested structure is formed by nesting an outer tube and an inner tube.

[0004] However, when manufacturing hollow-core optical fibers with multi-layer nested structures, since each cladding structure is an independent unit, the independent manufacturing of each cladding structure may lead to inconsistencies in thickness, shape and position between multiple cladding structures, reducing the overall manufacturing uniformity of the hollow-core optical fiber, thereby increasing the loss of hollow-core optical signal transmission. Summary of the invention

[0005] The present application provides a method for preparing a hollow-core optical fiber and a hollow-core optical fiber, which are used to solve the technical problem in the related art that the multiple cladding structures of the hollow-core optical fiber are uneven, thereby increasing the transmission loss of the optical signal of the hollow-core optical fiber.

[0006] In one aspect, the present application provides a method for manufacturing a hollow core optical fiber, comprising:

[0007] Arranging a plurality of tubular elements on the inner wall of the outer cladding along the circumference of the outer cladding;

[0008] Arranging a support element between adjacent tubular elements, and making the support element tangential to the tubular elements;

[0009] Arranging a central element coaxially with the outer cladding within the outer cladding, and abutting the central element against a plurality of the support elements;

[0010] Connecting the outer wall of the central element, the plurality of tubular elements and the spaces between the plurality of support elements to form a first connecting area, wherein the interior of the central element is an air-filled area;

[0011] heating the interior of the outer envelope;

[0012] The gas-filled region and the first communicating region are separately filled with gas, and the filling pressures in the gas-filled region and the first communicating region are adjusted so that the central element is deformed toward the center of the outer cladding to form a plurality of first anti-resonance layers arranged at intervals.

[0013] In some embodiments, connecting the outer wall of the central element, the plurality of tubular elements, and the spaces between the plurality of support elements to form a first connecting area comprises:

[0014] A first groove body is opened on a side of the support element away from the inner wall of the outer tube, and the first groove body is controlled to be arranged along the radial direction of the support element, so that the outer wall of the central element, the multiple tubular elements and the space between the multiple support elements are connected through the multiple first groove bodies to form a first connecting area.

[0015] In some embodiments, before heating the inner part of the outer cladding, the method comprises:

[0016] connecting the inner wall of the outer cladding, the spaces between the plurality of tubular elements and the plurality of support elements with the interiors of the plurality of tubular elements to form a second communication region;

[0017] After heating the interior of the outer cladding, the method further comprises:

[0018] Air is separately inflated into the second communication regions, and the inflation pressure in the second communication regions is adjusted so that the plurality of first tubular elements are deformed into the plurality of first anti-resonance layers to form a plurality of second anti-resonance layers.

[0019] In some embodiments, the inner wall of the outer cladding, the spaces between the plurality of tubular elements and the plurality of support elements are connected with the interiors of the plurality of tubular elements to form a second connected area, comprising:

[0020] A communication hole is formed on the tubular element and passes through the tubular element;

[0021] A second groove body is opened on one side of the support element close to the inner wall of the outer covering tube, and the second groove body is controlled to be arranged along the radial direction of the support element, so that the inner wall of the outer covering layer, the spaces between the multiple tubular elements and the multiple support elements are connected with the interior of the multiple tubular elements through the multiple second groove bodies to form a second connecting area.

[0022] In some embodiments, before arranging the central element coaxially with the outer cladding in the outer cladding, the method comprises:

[0023] Cutting the plurality of support elements to form a positioning groove for accommodating a portion of the central element on a side of each support element away from the inner wall of the outer cladding;

[0024] The positioning groove is honed, pickled and dried.

[0025] In some embodiments, the cutting of the plurality of support elements comprises:

[0026] A cutting surface is formed with the axis of the outer cladding as the center and R1 as the radius, and a plurality of the support elements are cut along the axis of the outer cladding through the cutting surface to form a positioning groove on the side of each support element away from the inner wall of the outer cladding, wherein R2-2R3>R1>R4, R2 is the inner radius of the outer cladding, R3 is the outer radius of the tubular element, and R4 is the outer radius of the central element.

[0027] In some embodiments, the heating of the interior of the outer envelope comprises:

[0028] heating the central element, the plurality of support elements and the plurality of tubular elements so that the tangent points between the central element and the plurality of support elements and between the plurality of support elements and the plurality of tubular elements are welded;

[0029] A sealing member is provided at the contact positions between the plurality of the supporting members and the plurality of the tubular members.

[0030] In some embodiments, the step of providing a seal at the contact positions of the plurality of support elements and the plurality of tubular elements comprises:

[0031] The sealing member formed by quartz is repair-welded to the contact positions between the plurality of the supporting elements and the plurality of the tubular elements.

[0032] In some embodiments, including:

[0033] The number of the tubular elements and the support elements, the inner radius of the outer cladding, the outer radius of the tubular element, the outer radius of the central element and the outer radius of the support element are controlled to satisfy the following formula:

[0034]

[0035] Wherein, X is the number of the tubular elements and the support elements, R2 is the inner radius of the outer cladding, R3 is the outer radius of the tubular element, R4 is the outer radius of the central element, and R5 is the outer radius of the support element.

[0036] On the other hand, the present application provides a hollow-core optical fiber, which is produced by the hollow-core optical fiber manufacturing method.

[0037] The present application provides a method for manufacturing a hollow-core optical fiber and a hollow-core optical fiber. The method for manufacturing a hollow-core optical fiber provided by the present application can support a central element by adopting the arrangement of multiple supporting elements. When the gas-filled area and the first connected area are separately inflated, the gas-filled area and the first connected area are adjusted and controlled so that the gas-filled pressure in the gas-filled area can keep the central element in contact with the multiple supporting elements, and the gas-filled pressure in the first connected area can cause the portion of the central element adjacent to the two supporting elements to deform simultaneously, so that multiple positions of the central element in a circumferential direction are synchronously deformed to form multiple first anti-resonance layers. Due to the arrangement of the gas-filled area, the first connected area and the multiple supporting elements, the multiple deformed first anti-resonance layers can have the same shape, thickness and position, thereby improving the uniformity of the overall manufacturing of the hollow-core optical fiber, thereby indirectly reducing the loss of the hollow-core optical fiber during optical signal transmission; by arranging the multiple first anti-resonance layers at intervals, the multiple first anti-resonance layers are not in contact with each other, so that the adjacent first anti-resonance layers are prevented from changing in shape after deformation and contact, so that the multiple first anti-resonance layers further have the same shape, thickness and position, thereby further improving the uniformity of the multiple first anti-resonance layers. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0039] Figure 1 A schematic diagram of the process structure of a method for manufacturing a hollow core optical fiber provided in an embodiment of the present application;

[0040] Figure 2 A schematic diagram of the structure of the outer cladding, tubular element and supporting element of the method for manufacturing a hollow core optical fiber provided in an embodiment of the present application;

[0041] Figure 3 A schematic structural diagram of a supporting element having a first groove body and a second groove body in a method for manufacturing a hollow core optical fiber provided in an embodiment of the present application;

[0042] Figure 4 for Figure 3 A schematic diagram of the structure from another angle;

[0043] Figure 5 A schematic diagram of the structure of the first groove body, the second groove body and the connecting hole provided in the method for manufacturing the hollow core optical fiber according to an embodiment of the present application;

[0044] Figure 6A schematic diagram of the structure of the hollow-core optical fiber manufacturing method provided in an embodiment of the present application before and after cutting a plurality of supporting elements;

[0045] Figure 7 A schematic diagram of the structure of the state where the central element of the method for manufacturing a hollow core optical fiber provided in an embodiment of the present application cooperates with a plurality of positioning grooves;

[0046] Figure 8 A schematic structural diagram of a state in which a central element of a method for manufacturing a hollow-core optical fiber provided in an embodiment of the present application is deformed to form a first anti-resonance layer;

[0047] Fig. 9 A schematic structural diagram of a state in which a tubular element is deformed to form a second antiresonance layer in a method for manufacturing a hollow-core optical fiber provided in an embodiment of the present application.

[0048] Description of reference numerals:

[0049] 100, outer layer;

[0050] 200, tubular element; 210, second anti-resonance layer; 220, communication hole; 221, first through hole; 222, second through hole;

[0051] 300, supporting element; 310, first slot body; 320, second slot body; 330, positioning slot;

[0052] 400, central element; 410, first anti-resonance layer;

[0053] 500. first connected region;

[0054] 600, inflation area;

[0055] 700. Second connected region.

[0056] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0057] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0058] As described in the background technology, the hollow-core optical fiber of the related technology includes a quartz tube and multiple cladding structures, the multiple cladding structures are evenly distributed along the circumference of the inner wall of the quartz tube, and the center position of the multiple cladding structures is an air core. When arranging the multiple cladding structures, it is necessary to maintain that there are no structural intersections or connection points between the multiple cladding structures, and each cladding structure is an independent unit. If there are intersections or connection points between adjacent cladding structures, the optical performance will be destroyed, resulting in reduced light wave transmission efficiency or poor mode control; the cladding structure of some hollow-core optical fibers adopts a multi-layer nested structure, and the multi-layer nested structure is formed by nesting an outer tube and an inner tube.

[0059] However, when manufacturing hollow-core optical fibers with multi-layer nested structures, since each cladding structure is an independent unit, when each cladding structure is manufactured independently, the thickness, shape and position of the multiple cladding structures may be inconsistent, reducing the uniformity of the overall manufacturing of the hollow-core optical fiber, thereby increasing the loss of the hollow-core optical signal transmission; for example, when each cladding structure is inflated and drawn, due to the uneven inflation pressure, the multiple cladding structures may be structurally inconsistent, such as a cladding structure is wider and a cladding structure is narrower, and cladding structures of different structures have different refractive indices, resulting in mode coupling and mode conversion, affecting the mode purity and performance of the optical fiber.

[0060] In view of the above technical problems, the embodiments of the present application provide a method for manufacturing a hollow-core optical fiber and a hollow-core optical fiber, by separately inflating the air-filled area, the first connected area, and the second connected area, and by adjusting the air-filled pressure in the first connected area and the second connected area to be equal, the air-filled pressure in the air-filled area is made smaller than the air-filled pressure in the first connected area and the second connected area, so that the portion between two adjacent supporting elements on the central element is deformed toward the axis of the outer cladding, and a plurality of first anti-resonance layers are formed at the same time, and at this time, the air-filled pressure in the second connected area is adjusted to be greater than the air-filled pressure in the first connected area, so that the tubular element is deformed toward the first anti-resonance layer. The plurality of first anti-resonance layers and the plurality of second anti-resonance layers can be formed simultaneously by deforming the plurality of support elements, the gas-filled regions, the first connected regions and the second connected regions, so that the plurality of first anti-resonance layers maintain structural consistency, and the plurality of second anti-resonance layers maintain structural consistency, so that the plurality of deformed first anti-resonance layers can have the same shape, thickness and position, and the plurality of deformed second anti-resonance layers can have the same shape, thickness and position, thereby improving the uniformity of the overall manufacturing of the hollow-core optical fiber, thereby indirectly reducing the loss of the hollow-core optical fiber during optical signal transmission.

[0061] The technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0062] Combination Figures 1 to 9 , a method for manufacturing a hollow core optical fiber, comprising:

[0063] S101: Arrange a plurality of tubular elements 200 on the inner wall of the outer cladding 100 along the circumference of the outer cladding 100;

[0064] S102: Arranging a support element 300 between adjacent tubular elements 200, and making the support element 300 tangent to the tubular element 200;

[0065] S103: Arrange the central element 400 coaxially with the outer cladding 100 in the outer cladding 100, and abut the central element 400 against the plurality of support elements 300;

[0066] S104: connecting the outer wall of the central element 400, the spaces between the plurality of tubular elements 200 and the plurality of support elements 300 to form a first connecting area 500, and the interior of the central element 400 is an inflatable area 600;

[0067] S105: heating the interior of the outer cladding 100;

[0068] S106 : Inflate the gas-filled region 600 and the first connected region 500 separately, and adjust the gas-filled pressure in the gas-filled region 600 and the first connected region 500 , so that the central element 400 deforms toward the center of the outer cladding 100 , so as to form a plurality of first anti-resonance layers 410 arranged at intervals.

[0069] In this embodiment, the cross-sections of the outer cladding 100, the tubular element 200 and the supporting element 300 are all circular, the outer cladding 100 and the tubular element 200 are hollow quartz tubes, and the supporting element 300 is a solid quartz rod; the quartz tube and the quartz rod are processed by drawing so that the quartz tube and the quartz rod form the outer cladding 100, the tubular element 200 and the supporting element 300; the drawing process of quartz material is a process of forming slender fibers or rods by stretching molten quartz, which is widely used in optical fiber communication, special optical fiber manufacturing, etc. Manufacturing and other fields, the specific process of drawing is no longer repeated in this embodiment; the number of tubular elements 200 and supporting elements 300 can be adaptively adjusted as needed. In this embodiment, 6 tubular elements 200 and 6 supporting elements 300 are provided, and the central element 400 is located in the middle of the 6 supporting elements 300; the lengths of the tubular elements 200, the supporting elements 300 and the central element 400 are all 1000mm; the lengths of the tubular elements 200, the supporting elements 300 and the central element 400 can be adaptively adjusted as needed.

[0070] By adopting the above technical solution, the central element 400 can be supported by the arrangement of multiple supporting elements 300. When the inflatable area 600 and the first connecting area 500 are inflated separately, the inflation pressure in the inflatable area 600 and the first connecting area 500 is adjusted and controlled, so that the inflation pressure in the inflatable area 600 can keep the central element 400 in contact with the multiple supporting elements 300, and the inflation pressure in the first connecting area 500 can make the part of the central element 400 adjacent to the two supporting elements 300 deform simultaneously, so that the central element 400 is synchronously deformed at multiple positions in the circumferential direction to form multiple first anti-resonance layers. 410, due to the arrangement of the gas-filled region 600, the first connected region 500 and the plurality of supporting elements 300, the plurality of deformed first anti-resonance layers 410 can have the same shape, thickness and position, thereby improving the uniformity of the overall manufacturing of the hollow-core optical fiber, thereby indirectly reducing the loss of the hollow-core optical fiber during optical signal transmission; by arranging the plurality of first anti-resonance layers 410 at intervals, the plurality of first anti-resonance layers 410 are not in contact with each other, thereby preventing the adjacent first anti-resonance layers 410 from changing in shape after deformation and contact, so that the plurality of first anti-resonance layers further have the same shape, thickness and position, thereby further improving the uniformity of the plurality of first anti-resonance layers 410.

[0071] Combination Figures 2 to 8 , connecting the outer wall of the central element 400, the spaces between the plurality of tubular elements 200 and the plurality of support elements 300 to form a first connecting area 500, including:

[0072] A first groove body 310 is opened on a side of the support element 300 away from the inner wall of the outer tube, and the first groove body 310 is controlled to be arranged along the radial direction of the support element 300, so that the outer wall of the central element 400, the multiple tubular elements 200 and the space between the multiple support elements 300 are connected through multiple first groove bodies 310 to form a first connecting area 500.

[0073] In this embodiment, the first groove body 310 penetrates the support element 300 on one side away from the axis of the support element 300, and the first groove body 310 penetrates the support element 300 at both ends along the radial direction of the support element 300. The spacing between the first groove body 310 and the end surface of the support element 300 is greater than or equal to 5 mm and less than or equal to 30 mm. The length of the first groove body 310 is greater than or equal to 5 mm and less than or equal to 30 mm. The first groove body 310 is perpendicular to the line connecting the axis of the support element 300 and the axis of the outer envelope 100. Before the support element 300 is arranged in the outer envelope 100, the first groove body 310 can be cut out on the support element 300 by mechanical cutting, so as to prevent the internal space of the outer envelope 100 from restricting human operation.

[0074] By adopting the above technical solution and the setting of the first slot bodies 310, the plurality of first slot bodies 310 can connect the outer wall of the central element 400, the spaces between the plurality of tubular elements 200 and the plurality of supporting elements 300 to form a first connecting area 500. When the first connecting area 500 is inflated, the gas can pass along the plurality of first slot bodies 310, so that the inflation pressure simultaneously acts on a plurality of positions of the central element 400 adjacent to two supporting elements 300 in the circumferential direction, so that the plurality of positions of the central element 400 in the circumferential direction are deformed simultaneously to form a plurality of first anti-resonance layers 410. The setting of the first slot bodies 310 has a simple structure and is easy to process, thereby improving the effect of connecting the outer wall of the central element 400, the spaces between the plurality of tubular elements 200 and the plurality of supporting elements 300.

[0075] Combination Figures 2 to 8 , before heating the interior of the outer envelope 100, comprising:

[0076] connecting the inner wall of the outer cladding 100, the spaces between the plurality of tubular elements 200 and the plurality of support elements 300 with the interior of the plurality of tubular elements 200 to form a second communication region 700;

[0077] After heating the interior of the outer envelope 100, including:

[0078] Air is separately inflated into the second communication regions 700 , and the inflation pressure in the second communication regions 700 is adjusted, so that the plurality of first tubular elements 200 are deformed into the plurality of first anti-resonance layers 410 to form the plurality of second anti-resonance layers 210 .

[0079] In this embodiment, there are six first anti-resonance layers 410 and six second anti-resonance layers 210. The six second anti-resonance layers 210 are arranged in the six first anti-resonance layers 410 in a one-to-one correspondence. The cross-sections of the first anti-resonance layers 410 and the second anti-resonance layers 210 are both arranged in an arc shape. The second anti-resonance layers 210 located in the first anti-resonance layers 410 do not contact the first anti-resonance layers 410.

[0080] By adopting the above technical solution, by forming the second anti-resonance layer 210 in the first anti-resonance layer 410, and by the arrangement of the first anti-resonance layer 410 and the second anti-resonance layer 210, more anti-resonance conditions can be provided, the restraining force of the light beam in the air core is increased, the light guiding efficiency of the hollow core optical fiber is improved, and the loss of optical signal transmission is reduced; by adopting the arrangement of the second connecting area 700, when the second connecting area 700 is inflated, the second connecting area 700 connects the multiple tubular elements 200, so that the inflation pressure can enter the multiple tubular elements 200 through the second connecting area 700 at the same time. The plurality of tubular elements 200 are deformed at the same time, so that the plurality of deformed second anti-resonance layers 210 can have the same shape, thickness and position, thereby improving the uniformity of the overall manufacturing of the hollow-core optical fiber, thereby indirectly reducing the loss of the hollow-core optical fiber during optical signal transmission; and the second anti-resonance layer 210 is located in the first anti-resonance layer 410, which can prevent the adjacent second anti-resonance layers 210 from changing in shape after deformation and contact, so that the plurality of second anti-resonance layers further have the same shape, thickness and position, thereby further improving the uniformity of the plurality of second anti-resonance layers 210.

[0081] Combination Figures 2 to 8 , connecting the inner wall of the outer cladding 100, the spaces between the plurality of tubular elements 200 and the plurality of support elements 300 with the interior of the plurality of tubular elements 200 to form a second connecting area 700, including:

[0082] A communication hole 220 is formed on the tubular element 200 and passes through the tubular element 200;

[0083] A second groove body 320 is opened on one side of the support element 300 close to the inner wall of the outer cladding tube, and the second groove body 320 is controlled to be arranged along the radial direction of the support element 300, so that the inner wall of the outer cladding 100, the spaces between the multiple tubular elements 200 and the multiple support elements 300 are connected with the interior of the multiple tubular elements 200 through the multiple second groove bodies 320 to form a second connecting area 700.

[0084] In this embodiment, since the tubular element 200 is hollow, the communicating holes 220 on each tubular element 200 include a first through hole 221 and a second through hole 222. The angle between the line connecting the first through hole 221 and the axis of the tubular element 200 and the line connecting the second through hole 222 and the axis of the tubular element 200 is 120°. The first through hole 221 and the second through hole 222 are symmetrically arranged along the axis of the tubular element 200 and the line connecting the tangent points of the tubular element 200 and the inner wall of the outer cladding 100. The first through hole 221 and the second through hole 222 are located in the tubular element 200. The first through hole 221 and the second through hole 222 are in the space between the tangent point of the tubular element 200 and the supporting element 300 and the tangent point of the tubular element 200 and the inner wall of the outer cladding 100; the spacing between the first through hole 221 and the second through hole 222 and the end face of the tubular element 200 is greater than or equal to 5 mm and less than or equal to 30 mm, and the radius of the first through hole 221 and the second through hole 222 is greater than or equal to 0.2 mm and less than or equal to 3 mm; before the tubular element 200 is arranged in the outer cladding 100, the first through hole 221 and the second through hole 222 can be drilled on the tubular element 200 by a drilling device.

[0085] In this embodiment, the second slot body 320 penetrates the support element 300 on one side away from the axis of the support element 300, and the second slot body 320 penetrates the support element 300 at both ends along the radial direction of the support element 300. The spacing between the second slot body 320 and the end surface of the support element 300 is greater than or equal to 5 mm and less than or equal to 30 mm, and the length of the second slot body 320 is greater than or equal to 5 mm and less than or equal to 30 mm; the second slot body 320 is perpendicular to the line connecting the axis of the support element 300 and the axis of the outer cladding 100; the second slot body 320 and the first slot body 310 are symmetrically distributed along the line connecting the tangent points of the tubular element 200 and the adjacent support element 300; before the support element 300 is arranged in the outer cladding 100, the second slot body 320 can be cut out on the support element 300 by mechanical cutting, so as to prevent the internal space of the outer cladding 100 from restricting human operation.

[0086] By adopting the above technical solution, when the second connecting region 700 is inflated, the gas can enter the inner wall of the outer cladding 100, the space between the plurality of tubular elements 200 and the plurality of supporting elements 300 along the second groove body 320, and enter the interior of the tubular element 200 along the connecting hole 220. Since the tubular element 200 is tangent to the supporting element 300, the supporting element 300 can support the tubular element 200. By adjusting the inflation pressure in the first connecting region 500 and the second connecting region 700 respectively, the plurality of tubular elements 200 are deformed simultaneously to form a plurality of second anti-resonance layers 210. By adopting the arrangement of the connecting hole 220 and the second groove body 320, the structure is simple and easy to process, and the connecting effect of connecting the inner wall of the outer cladding 100, the space between the plurality of tubular elements 200 and the plurality of supporting elements 300 with the interior of the plurality of tubular elements 200 is improved.

[0087] Combination Figure 5 to Figure 6 , before arranging the central element 400 coaxially with the outer cladding 100 in the outer cladding 100, comprising:

[0088] Cutting a plurality of support elements 300 to form a positioning groove 330 for accommodating a portion of the central element 400 on a side of each support element 300 away from the inner wall of the outer cladding 100;

[0089] The positioning groove 330 is honed, pickled and dried.

[0090] In this embodiment, honing includes:

[0091] Choose the appropriate honing head and abrasive. The honing head is usually made of abrasives such as oilstone or diamond;

[0092] Fix the support element 300 on the workbench of the honing machine to ensure that it is stable and accurately positioned;

[0093] Start the honing machine and make the honing head contact with the side of the support element 300 away from the inner wall of the outer cladding 100;

[0094] The honing head performs reciprocating and rotating motions on the support element 300 under the action of external force to achieve grinding;

[0095] During the honing process, the surface roughness of the positioning groove 330 is controlled to reach Ra0.2;

[0096] When the surface roughness of the positioning groove 330 reaches the requirement, the honing is stopped;

[0097] After honing is completed, a cleaning agent is used to remove grinding chips and debris from the surface of the preform.

[0098] Pickling includes:

[0099] According to a volume ratio of 4:1, 40% hydrofluoric acid and 68% nitric acid are mixed to form a pickling solution;

[0100] Immersing the honed support element 300 in a pickling solution to remove surface impurities and oxide layers;

[0101] After pickling, the support element 300 is rinsed with a large amount of clean water to neutralize the residual pickling solution;

[0102] Drying includes:

[0103] The pickled support element 300 is placed in a dust-free environment to allow the water to evaporate naturally;

[0104] If you need to speed up the drying process, you can use hot air drying equipment;

[0105] After drying is complete, the surface of the support element 300 is inspected to confirm that there is no residual moisture or contaminants.

[0106] In other embodiments, honing, pickling and drying may also be used to treat the outer cladding 100, the tubular element 200 and the central element 400.

[0107] By adopting the above technical solution and setting the positioning grooves 330, the central element 400 can be located in the multiple positioning grooves 330, so that the multiple positioning grooves 330 have a positioning effect on the central element 400, and prevent the axis of the central element 400 from deviating from the axis of the outer cladding 100; and the setting of the positioning grooves 330 increases the contact area with the central element 400, thereby indirectly improving the supporting effect of the supporting element 300 on the central element 400, preventing the part of the central element 400 abutting against the positioning grooves 330 from being deformed, thereby further improving the consistency of the shape, thickness and position of the multiple first anti-resonance layers 410; by honing, pickling and drying the positioning grooves 330, impurities on the inner wall of the positioning grooves 330 can be removed, thereby improving the processing accuracy and surface quality of the positioning grooves 330, and indirectly improving the contact effect and connection effect between the central element 400 and the positioning grooves 330.

[0108] Combination Figures 5 to 6 , cutting a plurality of support elements 300, comprising:

[0109] A cutting surface is formed with the axis of the outer cladding 100 as the center and R1 as the radius, and a plurality of support elements 300 are cut along the axis direction of the outer cladding 100 through the cutting surface to form a positioning groove 330 on a side of each support element 300 away from the inner wall of the outer cladding 100, wherein R2-2R3>R1>R4, R2 is the inner radius of the outer cladding 100, R3 is the outer radius of the tubular element 200, and R4 is the outer radius of the central element 400.

[0110] In this embodiment, the combined outer cladding 100 , the plurality of tubular elements 200 and the plurality of support elements 300 are placed on a lathe, and the plurality of support elements 300 are processed simultaneously by a drill bit of the lathe, so that the plurality of support elements 300 are cut simultaneously.

[0111] By adopting the above technical solution, a cutting surface is formed with the axis of the outer cladding 100 as the center and R1 as the radius, and the cutting surface is used to cut the multiple support elements 300 along the axis direction of the outer cladding 100, so that the positioning grooves 330 can be processed on the multiple support elements 300 at the same time, thereby improving the processing efficiency of the multiple positioning grooves 330 and improving the processing accuracy of the positioning grooves 330 on the multiple support elements 300, so that the multiple positioning grooves 330 can maintain consistency in structure, and indirectly improve the structural consistency of the multiple first anti-resonance layers 410.

[0112] The internal heating of the outer envelope 100 comprises:

[0113] heating the central element 400, the plurality of support elements 300 and the plurality of tubular elements 200 so that the tangent points between the central element 400 and the plurality of support elements 300 and between the plurality of support elements 300 and the plurality of tubular elements 200 are welded;

[0114] A seal is provided at the contact position between the plurality of support members 300 and the plurality of tubular members 200 .

[0115] In this embodiment, when it is necessary to heat the inside of the outer cladding 100, the outer cladding 100 is placed on a lathe provided with a movable heating source, which may be a graphite heating furnace, an induction heating furnace or a circular gas burner; the heating temperature of the heating source is 100°C to 2300°C; the heating source may be reciprocated on the inner wall of the outer cladding tube to achieve heating of the inside of the outer cladding 100, or the heating source may be reciprocated on the outside of the outer cladding tube to achieve heating of the entire outer cladding 100, and the central element 400, the supporting element 300 and the tubular element 200 may be heated to a semi-molten state, thereby achieving fusion of the tangent points.

[0116] By adopting the above technical solution, the central element 400, the supporting element 300 and the tubular element 200 are heated so that the tangent points of the central element 400 and the supporting element 300 are welded, thereby improving the connection strength between the central element 400 and the supporting element 300, preventing the central element 400 and the supporting element 300 from being separated when inflating into the first connecting area 500, thereby preventing the partial deformation of the central element 400 corresponding to the supporting element 300, thereby further improving the structural consistency of the multiple first anti-resonance layers 410; the tangent points of the multiple supporting elements 300 and the multiple tubular elements 200 are welded, which can prevent the supporting element 300 and the tubular element 200 from being separated when inflating into the second connecting area 700. The sealing performance between the support element 300 and the tubular element 200 is improved, and the gas in the second connecting area 700 is prevented from leaking into the first connecting area 500, so that the first connecting area 500 and the second connecting area 700 are maintained with different inflation pressures, which facilitates the molding of the plurality of first anti-resonance layers 410 and the plurality of second anti-resonance layers 210; by arranging a sealing member at the contact position between the support element 300 and the tubular element 200, the sealing member further improves the sealing performance between the tubular element 200 and the support element 300, further prevents the gas in the second connecting area 700 from leaking into the first connecting area 500, and further maintains the first connecting area 500 and the second connecting area 700 with different inflation pressures.

[0117] The contact positions of the plurality of support elements 300 and the plurality of tubular elements 200 are provided with sealing elements, comprising:

[0118] A sealing member formed of quartz is repair-welded to the contact positions between the plurality of support members 300 and the plurality of tubular members 200 .

[0119] In this embodiment, the quartz repair welding includes:

[0120] Clean the surfaces of the support element 300 and the tubular element 200 to be welded to remove dust, oil or other contaminants;

[0121] Place the supporting element 300 and tubular element 200 that need to be repaired in the correct position and fix them with a clamp;

[0122] Repair welding using TIG (inert gas tungsten arc welding) or other techniques suitable for quartz welding;

[0123] The quartz welding wire or welding powder is melted by an arc generated by a welding machine and filled into the contact position between the supporting element 300 and the tubular element 200;

[0124] During welding, a shielding gas (such as argon or helium) is used to cover the welding area to prevent oxidation of the quartz material;

[0125] Allow the welded quartz material to cool naturally or according to process requirements;

[0126] Perform post-processing such as grinding and polishing on the welding area;

[0127] A leak test is performed to ensure the tightness between the tubular element 200 and the support element 300 .

[0128] By adopting the above technical solution, the contact position between the support element 300 and the tubular element 200 is sealed by using quartz repair welding, and the quartz material has good airtightness; and the quartz material has excellent high temperature resistance; the quartz material itself has good chemical stability, and the joints after repair welding can maintain this stability and resist corrosion and chemical erosion; quartz is an excellent optical material, and the repair welding technology can be used to maintain or restore the optical properties of hollow-core optical fibers, such as transmittance and refractive index.

[0129] Combination Figures 4 to 8 , the method for preparing the hollow optical fiber further comprises:

[0130] The number of the tubular element 200 and the support element 300 is controlled, and the inner radius of the outer cladding 100, the outer radius of the tubular element 200, the outer radius of the central element 400 and the outer radius of the support element 300 satisfy the following formula:

[0131]

[0132] Wherein, X is the number of tubular elements 200 and support elements 300, R2 is the inner radius of the outer cladding 100, R3 is the outer radius of the tubular element 200, R4 is the outer radius of the central element 400, and R5 is the outer radius of the support element 300.

[0133] In this embodiment, the wall thickness of the tubular element 200 is greater than or equal to 0.1 mm and less than or equal to 3 mm, the outer radius of the outer cladding 100 is 10 mm to 35 mm larger than the inner radius R2 of the outer cladding 100, the inner radius R2 of the outer cladding 100 is greater than or equal to 25 mm and less than or equal to 50 mm, the outer radius R4 of the central element 400 is greater than or equal to 5 mm and less than or equal to 25 mm, and the outer radius R5 of the support element 300 is greater than or equal to 5 mm and less than or equal to 30 mm.

[0134] In this embodiment, the wall thickness t1 of the first anti-resonance layer 410 is greater than or equal to 0.1 μm and less than or equal to 2 μm, and the wall thickness t2 of the second anti-resonance layer 210 is also greater than or equal to 0.1 μm and less than or equal to 2 μm; t1 and t2 satisfy the following formula:

[0135]

[0136] Among them, t1 can also be t2, is the resonant wavelength, m is the antiresonant layer order, and n is the antiresonant refractive index.

[0137] The following is further described in conjunction with specific embodiments:

[0138] In the present embodiment, the inner radius R2 of the outer cladding 100 is set to 25 mm, the outer radius R4 of the outer cladding 100 is set to 50 mm, the outer radius R4 of the central element 400 is set to 13 mm, the wall thickness of the central element 400 is set to 0.5 mm, the outer radius R5 of the support element 300 is set to 6 mm, the outer radius R3 of the tubular element 200 is set to 4.4 mm, the wall thickness of the tubular element 200 is set to 0.5 mm, the groove depth of the first groove body 310 and the second groove body 320 is set to 1.5 mm, the distance between the first groove body 310 and the second groove body 320 and the end surface of the support element 300 is set to 10 mm, the length of the first groove body 310 and the second groove body 320 is set to 15 mm, the distance between the first through hole 221 and the second through hole 222 and the end surface of the tubular element 200 is set to 10 mm, and the distance between the first through hole 221 and the second through hole 222 and the end surface of the tubular element 200 is set to 10 mm. 2 is set to 0.8mm, and the radius R1 of the cutting surface is set to 14.6mm; when inflating, a first air-filling microtube is inserted into the second connected area 700 for independent air supply, a second air-filling microtube is inserted into the first connected area 500 for independent air supply, and a third air-filling microtube is inserted into the inflatable area 600 for independent air supply; the inflation pressure of the third air-filling microtube is adjusted to 0.5KPa, and the inflation pressure of the first air-filling microtube and the inflation pressure of the second air-filling microtube are adjusted to 3.5KPa, so that the part between two adjacent supporting elements 300 on the central element 400 is deformed toward the center of the outer cladding 100, and six first anti-resonance layers 410 are formed at the same time, and the inflation pressure of the first air-filling microtube is adjusted to 5.2Kpa, so that the tubular element 200 is deformed toward the first anti-resonance layer 410, thereby forming six second anti-resonance layers 420 at the same time, realizing the manufacture of hollow-core optical fiber.

[0139] Through the manufacturing process of the above embodiment, a total of five hollow-core optical fibers are selected, of which three hollow-core optical fibers are arranged with the first slot body 310, the second slot body 320 and the connecting hole 220. The hollow-core optical fibers arranged with the first slot body 310, the second slot body 320 and the connecting hole 220 are as shown in serial numbers 1, 2 and 3 in Table 1. The remaining two groups of hollow-core optical fibers not arranged with the first slot body 310, the second slot body 320 and the connecting hole 220, and not arranged with the first slot body 310, the second slot body 320 and the connecting hole 220 are as shown in serial numbers 4 and 5 in Table 1. The hollow-core optical fibers not arranged with the first slot body 310, the second slot body 320 and the connecting hole 220 are made independent of the inflation part of the central element 400 and each tubular element 200, and each inflation part is separately inflated with an inflation microtube to adjust the inflation pressure; by measuring the attenuation value of the optical signal at the same position on the five groups of hollow-core optical fibers, for example, the attenuation value of the optical signal at a position 1550nm away from the optical signal transmitting end is shown in Table 1.

[0140] Table 1 Attenuation values ​​at 1550nm on hollow core optical fiber:

[0141]

[0142] Referring to Table 1, it can be seen that, for example, for the hollow-core optical fiber with the optical fiber number 1, the deviation of the radius of the first anti-resonance layer 410 is maintained within 0.2 μm, which means that the multiple first anti-resonance layers 410 have good consistency in radius, and the deviation of the radius of the second anti-resonance layer 210 is maintained within 0.2 μm, which means that the multiple second anti-resonance layers 210 have good consistency in radius, and the deviation of the wall thickness of the first anti-resonance layer 410 and the second anti-resonance layer 210 is maintained within 0.1 μm, which means that the first anti-resonance layer 410 and the second anti-resonance layer 210 have good consistency in wall thickness. By comparing serial numbers 1, 2 and 3 with serial numbers 4 and 5, it can be further reflected that, by adopting the arrangement of the first slot body 310, the second slot body 320 and the connecting hole 220, the multiple first anti-resonance layers 410 and the multiple first anti-resonance layers 410 have good consistency in radius and wall thickness, and the hollow-core optical fiber arranged with the first slot body 310, the second slot body 320 and the connecting hole 220 has a smaller attenuation value of the optical signal at 1550nm, which means that the arrangement of the first slot body 310, the second slot body 320 and the connecting hole 220 reduces the loss of the hollow-core optical fiber during optical signal transmission.

[0143] The present application provides a hollow-core optical fiber, which is produced by the hollow-core optical fiber manufacturing method of any of the above embodiments.

[0144] The method for manufacturing the hollow core optical fiber has been described in detail in the above embodiments and will not be described in detail here.

[0145] By separately inflating the inflated region 600, the first connected region 500, and the second connected region 700, the inflated pressures in the first connected region 500 and the second connected region 700 are adjusted to be equal, and the inflated pressure in the inflated region 600 is made smaller than the inflated pressure in the first connected region 500 and the second connected region 700, so that the portion between two adjacent support elements 300 on the central element 400 is deformed toward the axis of the outer cladding 100, and a plurality of first anti-resonance layers 410 are formed at the same time. At this time, the inflated pressure in the second connected region 700 is adjusted to be greater than the inflated pressure in the first connected region 500, so that the tubular element 200 is deformed toward the first anti-resonance layer 410, thereby forming The plurality of second anti-resonance layers 210 can be formed by forming a plurality of supporting elements 300, the gas-filled regions 600, the first connected regions 500 and the second connected regions 700 at the same time, so that the plurality of first anti-resonance layers 410 maintain consistency in structure, and the plurality of second anti-resonance layers 210 maintain consistency in structure, so that the plurality of deformed first anti-resonance layers 410 can have the same shape, thickness and position, and the plurality of deformed second anti-resonance layers 210 can have the same shape, thickness and position, thereby improving the uniformity of the overall manufacturing of the hollow-core optical fiber, thereby indirectly reducing the loss of the hollow-core optical fiber during optical signal transmission.

[0146] Finally, it should be noted that those skilled in the art will readily conceive of other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. The present invention is intended to cover any variations, uses or adaptations of the present invention, which follow the general principles of the present invention and include common knowledge or customary technical means in the art not disclosed by the present invention, are not limited to the precise structure described above and shown in the drawings, and may be modified and changed in various ways without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A method for manufacturing a hollow core optical fiber, characterized in that: include: Arranging a plurality of tubular elements (200) on the inner wall of the outer cladding (100) along the circumference of the outer cladding (100); Arranging a support element (300) between adjacent tubular elements (200), and making the support element (300) tangential to the tubular element (200); Arranging a central element (400) coaxially with the outer cladding (100) in the outer cladding (100), and abutting the central element (400) against the plurality of support elements (300); The outer wall of the central element (400), the spaces between the plurality of tubular elements (200) and the plurality of support elements (300) are connected to form a first connecting area (500), and the interior of the central element (400) is an air-filled area (600); heating the interior of the outer cladding layer (100); Inflate the gas-filled area (600) and the first connected area (500) separately, and adjust the gas-filled pressure in the gas-filled area (600) and the first connected area (500), so that the central element (400) is deformed toward the center of the outer cladding (100), so as to form a plurality of first anti-resonance layers (410) arranged at intervals; Before heating the interior of the outer cladding (100), the method comprises: connecting the inner wall of the outer cladding (100), the spaces between the plurality of tubular elements (200) and the plurality of support elements (300) with the interiors of the plurality of tubular elements (200) to form a second communication region (700); After heating the interior of the outer cladding (100), the method further comprises: The second communication regions (700) are inflated with gas separately, and the inflation pressure in the second communication regions (700) is adjusted so that the plurality of tubular elements (200) are deformed into the plurality of first anti-resonance layers (410) to form a plurality of second anti-resonance layers (210).

2. The method for manufacturing a hollow core optical fiber according to claim 1, characterized in that: The method of connecting the outer wall of the central element (400), the spaces between the plurality of tubular elements (200) and the plurality of support elements (300) to form a first connecting area (500) comprises: A first groove body (310) is provided on a side of the support element (300) away from the inner wall of the outer tube, and the first groove body (310) is controlled to be arranged along the radial direction of the support element (300) so that the outer wall of the central element (400), the spaces between the multiple tubular elements (200) and the multiple support elements (300) are connected through the multiple first groove bodies (310) to form a first connecting area (500).

3. The method for manufacturing a hollow core optical fiber according to claim 1, characterized in that: The method of connecting the inner wall of the outer cladding layer (100), the spaces between the plurality of tubular elements (200) and the plurality of support elements (300) with the interior of the plurality of tubular elements (200) to form a second connecting area (700) comprises: A communication hole (220) is provided on the tubular element (200) and passes through the tubular element (200); A second groove body (320) is provided on one side of the support element (300) close to the inner wall of the outer cladding tube, and the second groove body (320) is controlled to be arranged along the radial direction of the support element (300), so that the inner wall of the outer cladding layer (100), the spaces between the plurality of tubular elements (200) and the plurality of support elements (300) are connected with the interior of the plurality of tubular elements (200) through the plurality of second groove bodies (320) to form a second connecting area (700).

4. The method for manufacturing a hollow core optical fiber according to any one of claims 1 to 3, characterized in that: Before arranging the central element (400) coaxially with the outer cladding (100) in the outer cladding (100), the method comprises: Cutting the plurality of support elements (300) to form a positioning groove (330) for accommodating a portion of the central element (400) on a side of each support element (300) away from the inner wall of the outer cladding (100); The positioning groove (330) is honed, pickled and dried.

5. The method for manufacturing a hollow core optical fiber according to claim 4, characterized in that: The cutting of the plurality of support elements (300) comprises: A cutting surface is formed with the axis of the outer cladding (100) as the center and R1 as the radius, and a plurality of the support elements (300) are cut along the axis of the outer cladding (100) through the cutting surface to form a positioning groove (330) on a side of each support element (300) away from the inner wall of the outer cladding (100), wherein R2-2R3>R1>R4, R2 is the inner radius of the outer cladding (100), R3 is the outer radius of the tubular element (200), and R4 is the outer radius of the central element (400).

6. The method for manufacturing a hollow core optical fiber according to any one of claims 1 to 3, characterized in that: The heating of the interior of the outer cladding layer (100) comprises: Heating the central element (400), the plurality of support elements (300) and the plurality of tubular elements (200) so that the tangent points of the central element (400) and the plurality of support elements (300) and the tangent points of the plurality of support elements (300) and the plurality of tubular elements (200) are welded; A sealing member is provided at the contact positions between the plurality of support members (300) and the plurality of tubular members (200).

7. The method for manufacturing a hollow core optical fiber according to claim 6, characterized in that: The step of providing a sealing member at the contact positions of the plurality of support elements (300) and the plurality of tubular elements (200) comprises: The sealing member formed by quartz is repair-welded to the contact positions between the plurality of the supporting elements (300) and the plurality of the tubular elements (200).

8. The method for manufacturing a hollow core optical fiber according to any one of claims 1 to 3, characterized in that: include: The number of the tubular element (200) and the support element (300) is controlled. The inner radius of the outer cladding (100), the outer radius of the tubular element (200), the outer radius of the central element (400) and the outer radius of the support element (300) satisfy the following formula: Wherein, X is the number of the tubular element (200) and the supporting element (300), R2 is the inner radius of the outer cladding (100), R3 is the outer radius of the tubular element (200), R4 is the outer radius of the central element (400), and R5 is the outer radius of the supporting element (300).

9. A hollow core optical fiber, characterized in that: The hollow-core optical fiber is produced by the method for manufacturing a hollow-core optical fiber according to any one of claims 1 to 8.

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