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

Abstract

The present application relates to the technical field of communication engineering, and provides a method for manufacturing a hollow-core optical fiber, and a hollow-core optical fiber. The method for manufacturing the hollow-core optical fiber comprises: arranging multiple tubular elements on an inner wall of an outer cladding layer; arranging supporting elements between adjacent tubular elements; coaxially arranging a central element within the outer cladding layer, and abutting the central element against the multiple supporting elements; placing spaces between the outer wall of the central element, the multiple tubular elements and the multiple supporting elements in communication, so as to form a first communication region, the interior of the central element being an air-filling region; heating the interior of the outer cladding layer; separately filling the air-filling region and the first communication region with air, and adjusting the air filling pressures in the air-filling region and the first communication region, so as to cause the central element to deform toward the center of the outer cladding layer, so as to form multiple spaced first anti-resonance layers. The method for manufacturing the hollow-core optical fiber provided in the present application reduces the loss of optical signal transmission in hollow-core optical fiber.

Description

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

[0001] The present application relates to the technical field of communication engineering, and in particular to a manufacturing method of a hollow core optical fiber and the hollow core optical fiber. BACKGROUND

[0002] The hollow core anti-resonant optical fiber uses air instead of glass material in the traditional optical fiber to transmit optical signals. This design helps to overcome the problems of nonlinearity, dispersion, optical damage and material absorption loss in the transmission process of the traditional solid core optical fiber; the light guiding mechanism of the hollow core anti-resonant optical fiber is mainly based on the anti-resonant effect, that is, the light waves are caused to be coherent and cancelled on the interface between the air core and the cladding of the optical fiber, so as to suppress the leakage of the light waves and realize the effective transmission of the optical signals.

[0003] The hollow core optical fiber of the related art includes a quartz tube and a plurality of cladding structures, the plurality of cladding structures are uniformly distributed along the circumference of the inner wall of the quartz tube, the center position of the plurality of cladding structures is an air core, when arranging the plurality of cladding structures, it is necessary to keep the plurality of cladding structures without intersection or connection point in structure, 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 mutually nesting an outer tube and an inner tube.

[0004] However, when manufacturing the hollow core optical fiber with the multi-layer nested structure, since each cladding structure is an independent unit, independent manufacturing of each cladding structure may cause the thickness, shape and position of the plurality of cladding structures to be inconsistent, thereby reducing the uniformity of the overall manufacturing of the hollow core optical fiber, and increasing the loss of the optical signal transmission of the hollow core optical fiber. SUMMARY

[0005] The present application provides a preparation method of a hollow core optical fiber and the hollow core optical fiber, to solve the technical problem that the plurality of cladding structures of the hollow core optical fiber are not uniform in the related art, thereby increasing the loss of the optical signal transmission of the hollow core optical fiber.

[0006] In one aspect, the present application provides a manufacturing method of 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 tangentially connecting the support element with the tubular element;

[0009] arranging a center element coaxially in the outer cladding, and abutting the center element with the plurality of support elements;

[0010] communicating a space between the outer wall of the center element, the plurality of tubular elements and the plurality of support elements to form a first communication region, the inside of the center element being an inflation region;

[0011] heating the inside of the outer cladding layer;

[0012] inflating the inflation region and the first communication region separately, and adjusting the inflation pressure in the inflation region and the first communication region, so that the center element deforms towards the center of the outer cladding layer to form a plurality of first anti-resonance layers arranged at intervals.

[0013] In some embodiments, the communicating a space between the outer wall of the center element, the plurality of tubular elements and the plurality of support elements to form a first communication region comprises:

[0014] opening a first groove on the side of the support element away from the inner wall of the outer cladding tube, and controlling the radial arrangement of the first groove along the support element, so that the space between the outer wall of the center element, the plurality of tubular elements and the plurality of support elements is communicated through the plurality of first grooves to form a first communication region.

[0015] In some embodiments, before the heating the inside of the outer cladding layer, comprising:

[0016] communicating a space between the inner wall of the outer cladding layer, the plurality of tubular elements and the plurality of support elements with the inside of the plurality of tubular elements to form a second communication region;

[0017] In some embodiments, after the heating the inside of the outer cladding layer, comprising:

[0018] inflating the second communication region separately, and adjusting the inflation pressure in the second communication region, so that the plurality of first tubular elements deforms into the plurality of first anti-resonance layers to form a plurality of second anti-resonance layers.

[0019] In some embodiments, the communicating a space between the inner wall of the outer cladding layer, the plurality of tubular elements and the plurality of support elements with the inside of the plurality of tubular elements to form a second communication region comprises:

[0020] opening a communication hole through the tubular element on the tubular element;

[0021] opening a second groove on the side of the support element close to the inner wall of the outer cladding tube, and controlling the radial arrangement of the second groove along the support element, so that the space between the inner wall of the outer cladding layer, the plurality of tubular elements and the plurality of support elements is communicated with the inside of the plurality of tubular elements through the plurality of second grooves to form a second communication region.

[0022] In some embodiments, before arranging the central element coaxially in the outer cladding layer, comprising:

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

[0024] Honing, pickling and drying the positioning grooves.

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

[0026] Forming a cutting surface with the axis of the outer cladding layer as the center and R1 as the radius, and cutting a plurality of the support elements along the axis of the outer cladding layer through the cutting surface to form positioning grooves on a side of each of the support elements away from the inner wall of the outer cladding layer, wherein R2-2R3>R1>R4, R2 is the inner radius of the outer cladding layer, 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 the inside of the outer cladding layer, comprising:

[0028] Heating the central element, a plurality of the support elements and a plurality of the tubular elements so that the central element and a plurality of the support elements and the contact points of a plurality of the support elements and a plurality of the tubular elements are welded;

[0029] Providing a sealing member at the contact position of a plurality of the support elements and a plurality of the tubular elements.

[0030] In some embodiments, the providing a sealing member at the contact position of a plurality of the support elements and a plurality of the tubular elements, comprising:

[0031] Supplementing the sealing member formed by quartz at the contact position of a plurality of the support elements and a plurality of the tubular elements.

[0032] In some embodiments, comprising:

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

[0034] Wherein X is the number of the tubular elements and the support elements, R2 is the inner radius of the outer cladding layer, 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.

[0035] In another aspect, the present application provides an air-core optical fiber produced by the method for manufacturing an air-core optical fiber.

[0036] The present application provides a method for manufacturing an air-core optical fiber and an air-core optical fiber. The method for manufacturing an air-core optical fiber provided by the present application can support the central element by arranging a plurality of support elements. When the inflation area and the first communication area are inflated separately, the inflation pressure in the inflation area can keep the central element in abutment with the plurality of support elements, and the inflation pressure in the first communication area can make the central element deform simultaneously at the portion adjacent to the two support elements, so that the central element deforms synchronously at a plurality of positions in the circumferential direction to form a plurality of first anti-resonance layers. Due to the arrangement of the inflation area, the first communication area and the plurality of support elements, the plurality of deformed first anti-resonance layers can have the same shape, thickness and position, thereby improving the uniformity of the overall manufacturing of the air-core optical fiber and indirectly reducing the loss of the air-core optical fiber during optical signal transmission. The plurality of first anti-resonance layers are arranged at intervals, so that there is no contact between the plurality of first anti-resonance layers, preventing the shape of the adjacent first anti-resonance layers from changing 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. BRIEF DESCRIPTION OF DRAWINGS

[0037] The accompanying drawings, which are incorporated into and form a part of the specification, illustrate an embodiment consistent with the present application and, together with the specification, serve to explain the principles of the application.

[0038] FIG. 1 is a flow structure schematic diagram of the method for manufacturing an air-core optical fiber provided by the present application;

[0039] FIG. 2 is a structure schematic diagram of the outer cladding, tubular element and support element of the method for manufacturing an air-core optical fiber provided by the present application;

[0040] FIG. 3 is a structure schematic diagram of the support element with the first groove and the second groove of the method for manufacturing an air-core optical fiber provided by the present application;

[0041] FIG. 4 is a structure schematic diagram from another angle of FIG. 3;

[0042] FIG. 5 is a structure schematic diagram of the support element with the first groove, the second groove and the communication hole of the method for manufacturing an air-core optical fiber provided by the present application;

[0043] FIG. 6 is a structure schematic diagram of the state before and after cutting the plurality of support elements of the method for manufacturing an air-core optical fiber provided by the present application;

[0044] Fig. 7 is a schematic structural diagram of a central element of a hollow optical fiber manufacturing method according to an embodiment of the present application in a state of cooperation with a plurality of positioning grooves;

[0045] Fig. 8 is a schematic structural diagram of a central element of a hollow optical fiber manufacturing method according to an embodiment of the present application in a state of deforming to form a first anti-resonance layer;

[0046] Fig. 9 is a schematic structural diagram of a tubular element of a hollow optical fiber manufacturing method according to an embodiment of the present application in a state of deforming to form a second anti-resonance layer.

[0047] Legend: 100, outer cladding; 200, tubular element; 210, second anti-resonance layer; 220, communication hole; 221, first through hole; 222, second through hole; 300, support element; 310, first groove; 320, second groove; 330, positioning groove; 400, central element; 410, first anti-resonance layer; 500, first communication region; 600, inflation region; 700, second communication region.

[0048] The above-described figures have shown specific embodiments of the present application, which will be described in more detail hereinafter. These figures and written descriptions are not intended to limit the scope of the concept 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

[0049] Exemplary embodiments will be described in detail herein with reference to the attached drawings. In the following description, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments are not representative of all embodiments consistent with the present application. Rather, they are merely examples of devices and methods consistent with some aspects of the present application, as detailed in the appended claims.

[0050] As described in the background section, a hollow optical fiber of the related art includes a quartz tube and a plurality of cladding structures uniformly distributed along the circumference of the inner wall of the quartz tube, and the center of the plurality of cladding structures is an air core. When the plurality of cladding structures are arranged, the plurality of cladding structures should not have any intersection or connection points therebetween in structure. Each cladding structure is an independent unit. If there is an intersection or connection point between adjacent cladding structures, the optical performance is damaged, resulting in a decrease in light wave transmission efficiency or poor mode control. Some cladding structures of the hollow optical fiber have a multi-layer nested structure formed by mutually nesting an outer tube and an inner tube.

[0051] However, when manufacturing the hollow core fiber with the multi-layer nested structure, since each cladding structure is an independent unit, independent manufacturing of each cladding structure may cause the thickness, shape and position of the multiple cladding structures to be inconsistent, reducing the uniformity of the overall manufacturing of the hollow core fiber, thereby increasing the loss of the hollow core fiber in 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 inconsistent in structure, for example, a certain cladding structure is wider, and a certain cladding structure is narrower, the cladding structures of different structures have different refractive indexes, causing mode coupling and mode conversion, affecting the mode purity and performance of the optical fiber.

[0052] To solve the above technical problems, the embodiments of the present application provide a manufacturing method of a hollow core fiber and a hollow core fiber. By separately inflating the inflation area, the first communication area and the second communication area, by adjusting the inflation pressure in the first communication area and the second communication area to be equal, the inflation pressure in the inflation area is less than the inflation pressure in the first communication area and the second communication area, so that the part between the two adjacent support elements on the central element deforms towards the axis of the outer cladding, and at the same time, multiple first anti-resonance layers are formed. At this time, the inflation pressure in the second communication area is adjusted to be greater than the inflation pressure in the first communication area, so that the tubular element deforms towards the first anti-resonance layer, thereby simultaneously forming multiple second anti-resonance layers. By using the arrangement of multiple support elements, inflation areas, first communication areas and second communication areas, multiple first anti-resonance layers and multiple second anti-resonance layers can be formed at the same time, so that the multiple first anti-resonance layers remain consistent in structure, and the multiple second anti-resonance layers remain consistent in structure, so that the multiple deformed first anti-resonance layers can have the same shape, thickness and position, and the multiple 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 fiber, thereby indirectly reducing the loss of the hollow core fiber in optical signal transmission.

[0053] The technical solutions of the present application and how the technical solutions of the present application solve the above technical problems will be described in detail in the specific embodiments below. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of the present application will be described below with reference to the accompanying drawings.

[0054] In combination with FIGS. 1 to 9, a manufacturing method of a hollow core fiber comprises:

[0055] S101: arranging multiple tubular elements 200 on the inner wall of the outer cladding 100 along the circumference of the outer cladding 100;

[0056] S102: arranging a support element 300 between adjacent tubular elements 200, and making the support element 300 tangent to the tubular element 200;

[0057] S103: arranging the central element 400 coaxially with the outer cladding 100 in the outer cladding 100, and abutting the central element 400 with the plurality of support elements 300;

[0058] S104: communicating the space between the outer wall of the central element 400, the plurality of tubular elements 200 and the plurality of support elements 300 to form a first communication area 500, and the inside of the central element 400 is a gas-filled area 600;

[0059] S105: heating the inside of the outer cladding 100;

[0060] S106: separately inflating the gas-filled area 600 and the first communication area 500, and adjusting the inflation pressure in the gas-filled area 600 and the first communication area 500, so that the central element 400 is deformed towards the center of the outer cladding 100 to form a plurality of spaced first anti-resonance layers 410.

[0061] In the present embodiment, the cross sections of the outer cladding 100, the tubular elements 200 and the support elements 300 are all circular, the outer cladding 100 and the tubular elements 200 are hollow quartz tubes, and the support elements 300 are solid quartz rods; the quartz tubes and the quartz rods are processed by drawing to form the outer cladding 100, the tubular elements 200 and the support elements 300; the drawing process of quartz material is a process of forming an elongated fiber or rod from molten quartz by stretching, which is widely used in the fields of optical fiber communication and special optical fiber manufacturing, and the specific process of drawing will not be described in detail in the present embodiment; the number of the tubular elements 200 and the support elements 300 can be adjusted as needed, in the present embodiment, the tubular elements 200 and the support elements 300 are each provided with 6, and the central element 400 is located in the middle of the 6 support elements 300; the lengths of the tubular elements 200, the support elements 300 and the central element 400 are all 1000 mm; the lengths of the tubular elements 200, the support elements 300 and the central element 400 can be adjusted as needed.

[0062] By adopting the above technical scheme, the arrangement of the plurality of support elements 300 can support the center element 400. When the inflation area 600 and the first communication area 500 are inflated separately, by adjusting and controlling the inflation pressure in the inflation area 600 and the first communication area 500, the inflation pressure in the inflation area 600 can keep the center element 400 in abutment with the plurality of support elements 300, and the inflation pressure in the first communication area 500 can make the center element 400 deform simultaneously at the portion adjacent to the two support elements 300, so that the center element 400 deforms synchronously at a plurality of circumferential positions to form a plurality of first anti-resonance layers 410. Due to the arrangement of the inflation area 600, the first communication area 500, and the plurality of support 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 whole hollow core fiber manufacturing, and indirectly reducing the loss of the hollow core fiber during optical signal transmission. By spacing the plurality of first anti-resonance layers 410, the plurality of first anti-resonance layers 410 are not in contact with each other, preventing the shape of the adjacent first anti-resonance layers 410 from changing after deformation and contact, so that the plurality of first anti-resonance layers 410 further have the same shape, thickness, and position, thereby further improving the uniformity of the plurality of first anti-resonance layers 410.

[0063] In combination with FIGS. 2 to 8, the space between the outer wall of the center element 400, the plurality of tubular elements 200, and the plurality of support elements 300 is communicated to form the first communication area 500, including:

[0064] The first groove 310 is arranged on the side of the support element 300 away from the inner wall of the outer cladding tube, and the first groove 310 is arranged in the radial direction of the support element 300, so as to communicate the space between the outer wall of the center element 400, the plurality of tubular elements 200, and the plurality of support elements 300 through the plurality of first grooves 310 to form the first communication area 500.

[0065] In the present embodiment, the first groove 310 penetrates the support element 300 on the side away from the axis of the support element 300, the first groove 310 penetrates the support element 300 at both ends in the radial direction of the support element 300, the distance between the first groove 310 and the end face 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 first groove 310 is greater than or equal to 5 mm and less than or equal to 30 mm; the first groove 310 is perpendicular to the line connecting the axis of the support element 300 and the axis of the outer cladding layer 100; before the support element 300 is arranged in the outer cladding layer 100, the first groove 310 can be cut on the support element 300 by mechanical cutting, thereby preventing the space inside the outer cladding layer 100 from limiting the operation of personnel.

[0066] By adopting the technical scheme, the first grooves 310 are arranged to connect the space between the outer wall of the central element 400, the plurality of tubular elements 200 and the plurality of support elements 300 to form a first communication area 500, when the first communication area 500 is filled with gas, the gas can pass through the plurality of first grooves 310, so that the inflation pressure acts on the plurality of positions between the two adjacent support elements 300 on the circumference of the central element 400, so that the plurality of positions on the circumference of the central element 400 are deformed to form a plurality of first anti-resonance layers 410; the first grooves 310 are simple in structure and easy to process, and the connection effect of the space between the outer wall of the central element 400, the plurality of tubular elements 200 and the plurality of support elements 300 is improved.

[0067] In combination with FIGS. 2 to 8, before the inside of the outer cladding 100 is heated, comprising:

[0068] The space between the inner wall of the outer cladding 100, the plurality of tubular elements 200 and the plurality of support elements 300 is connected with the inside of the plurality of tubular elements 200 to form a second communication area 700;

[0069] After the inside of the outer cladding 100 is heated, comprising:

[0070] The second communication area 700 is separately inflated, and the inflation pressure in the second communication area 700 is adjusted to deform the plurality of first tubular elements 200 into the plurality of first anti-resonance layers 410 to form a plurality of second anti-resonance layers 210.

[0071] In the embodiment, the first anti-resonance layer 410 has 6, the second anti-resonance layer 210 has 6, the 6 second anti-resonance layers 210 are arranged one by one in the 6 first anti-resonance layers 410, the cross sections of the first anti-resonance layer 410 and the second anti-resonance layer 210 are arranged in an arc shape, and the second anti-resonance layer 210 in the first anti-resonance layer 410 is not in contact with the first anti-resonance layer 410.

[0072] By adopting the above technical scheme, by forming the second anti-resonance layer 210 in the first anti-resonance layer 410, through the setting of the first anti-resonance layer 410 cooperating with the second anti-resonance layer 210, more anti-resonance conditions can be provided, the confinement 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 setting of the second communication area 700, when the second communication area 700 is filled with gas, because the second communication area 700 communicates the plurality of tubular elements 200, the inflation pressure can enter the plurality of tubular elements 200 through the second communication area 700, so that 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, improve the uniformity of the whole manufacturing of the hollow core optical fiber, thereby indirectly reducing the loss of the hollow core optical fiber in the 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 shape after deformation contact, so that the plurality of second anti-resonances further have the same shape, thickness and position, thereby further improving the uniformity of the plurality of second anti-resonance layers 210.

[0073] In combination with FIGS. 2-8, the space between the inner wall of the cladding layer 100, the plurality of tubular elements 200 and the plurality of support elements 300 and the inside of the plurality of tubular elements 200 is communicated to form the second communication area 700, comprising:

[0074] A communication hole 220 is formed through the tubular element 200 on the tubular element 200;

[0075] A second groove 320 is formed on the side of the support element 300 close to the inner wall of the cladding tube, and the second groove 320 is arranged along the radial direction of the support element 300, so that the space between the inner wall of the cladding layer 100, the plurality of tubular elements 200 and the plurality of support elements 300 and the inside of the plurality of tubular elements 200 are communicated to form the second communication area 700.

[0076] In the embodiment, the communication holes 220 on each tubular element 200 include a first through hole 221 and a second through hole 222, the included 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 line connecting the axis of the tubular element 200 and the tangent point 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 space between the tangent point of the tubular element 200 and the support element 300 and the tangent point of the tubular element 200 and the inner wall of the outer cladding 100; the distance 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, 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 arranging the tubular element 200 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.

[0077] In the embodiment, the second groove 320 penetrates the support element 300 from the side away from the axis of the support element 300, the two ends of the second groove 320 along the radial direction of the support element 300 penetrate the support element 300, the distance between the second groove 320 and the end face 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 second groove 320 is greater than or equal to 5 mm and less than or equal to 30 mm; the second groove 320 is perpendicular to the line connecting the axis of the support element 300 and the axis of the outer cladding 100; the second groove 320 and the first groove 310 are symmetrically distributed along the line connecting the tangent point of the tubular element 200 and the adjacent support element 300; before arranging the support element 300 in the outer cladding 100, the second groove 320 can be cut on the support element 300 by a mechanical cutting device, thereby preventing the internal space of the outer cladding 100 from limiting the operation of personnel.

[0078] By adopting the above technical scheme, when the second communication area 700 is inflated, the gas can enter into the space between the inner wall of the outer cladding 100, the plurality of tubular elements 200 and the plurality of support elements 300 along the second groove 320, and enter into the inside of the tubular element 200 along the communication hole 220. Since the tubular element 200 is tangent to the support element 300, the support element 300 can support the tubular element 200. By respectively adjusting the inflation pressure in the first communication area 500 and the second communication area 700, the plurality of tubular elements 200 can be deformed to form a plurality of second anti-resonance layers 210 at the same time. By adopting the simple structure of the communication hole 220 and the second groove 320, the machining is facilitated, and the communication effect of the space between the inner wall of the outer cladding 100, the plurality of tubular elements 200 and the plurality of support elements 300 and the inside of the plurality of tubular elements 200 is improved.

[0079] In combination with FIGS. 5 to 6, before the central element 400 is arranged coaxially in the outer cladding 100, the following steps are included:

[0080] The plurality of support elements 300 are cut to form positioning grooves 330 on the side of each support element 300 away from the inner wall of the outer cladding 100 for accommodating part of the central element 400;

[0081] The positioning grooves 330 are honed, pickled and dried.

[0082] In this embodiment, the honing includes:

[0083] A suitable honing head and abrasive are selected, and the honing head is usually made of abrasive such as oilstone or diamond;

[0084] The support element 300 is fixed on the workbench of the honing machine to ensure its stability and accurate position;

[0085] The honing machine is started, and the honing head is in contact with the side of the support element 300 away from the inner wall of the outer cladding 100;

[0086] The honing head reciprocates and rotates on the support element 300 under the action of an external force to achieve grinding;

[0087] During the honing process, the roughness of the surface of the positioning groove 330 is controlled to reach Ra0.2;

[0088] When the roughness of the surface of the positioning groove 330 reaches the requirement, the honing is stopped;

[0089] After the honing is completed, a cleaning agent is used to remove the grinding dust and debris on the surface of the preform rod.

[0090] The pickling includes:

[0091] The 40% concentration hydrofluoric acid and the 68% concentration nitric acid are mixed in a ratio of 4:1 to form an acid pickling solution;

[0092] The honed support element 300 is immersed in the acid pickling solution to remove surface impurities and oxide layers;

[0093] After acid pickling, the support element 300 is rinsed with a large amount of clean water to neutralize the residual acid pickling solution;

[0094] Drying includes:

[0095] The acid-pickled support element 300 is placed in a dust-free environment to allow the moisture to evaporate naturally;

[0096] If it is necessary to speed up the drying speed, a hot air drying device can be used;

[0097] After drying is completed, the surface of the support element 300 is checked to confirm that there is no residual moisture and no contaminants.

[0098] In other embodiments, the outer cladding 100, the tubular element 200, and the central element 400 can also be processed by honing, acid pickling, and drying.

[0099] By adopting the technical scheme, the central element 400 is located in the plurality of positioning grooves 330, the plurality of positioning grooves 330 have a positioning effect on the central element 400, and the axis of the central element 400 is prevented from deviating from the axis of the outer cladding 100. The positioning groove 330 increases the contact area with the central element 400, thereby indirectly improving the supporting effect of the support element 300 on the central element 400, preventing deformation of the portion of the central element 400 abutting against the positioning groove 330, and further improving the consistency of the plurality of first anti-resonance layers 410 in shape, thickness, and position. By honing, acid pickling, and drying the positioning groove 330, impurities on the inner wall of the positioning groove 330 can be removed, thereby improving the machining precision and surface quality of the positioning groove 330 and indirectly improving the contact effect and connection effect of the central element 400 and the positioning groove 330.

[0100] In combination with FIGS. 5-6, the plurality of support elements 300 are cut, including:

[0101] A cutting surface is formed with the axis of the outer cladding 100 as the center and R1 as the radius, the plurality of support elements 300 are cut along the axis of the outer cladding 100 through the cutting surface to form the positioning groove 330 on the side of each support element 300 away from the inner wall of the outer cladding 100, and 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.

[0102] In the 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 simultaneously machined by a drill bit of the lathe to achieve simultaneous cutting of the plurality of support elements 300.

[0103] By adopting the above technical solution, the 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 cut along the axis direction of the outer cladding 100 to the plurality of support elements 300, so that the positioning grooves 330 can be simultaneously machined on the plurality of support elements 300, the machining efficiency of the plurality of positioning grooves 330 is improved, the machining precision of the positioning grooves 330 on the plurality of support elements 300 is improved, the plurality of positioning grooves 330 can maintain consistency in structure, and the consistency of the plurality of first anti-resonance layers 410 in structure is indirectly improved.

[0104] The inside of the outer cladding 100 is heated, including:

[0105] The center element 400, the plurality of support elements 300 and the plurality of tubular elements 200 are heated to fuse the cutting points of the center element 400 and the plurality of support elements 300 and the plurality of support elements 300 and the plurality of tubular elements 200.

[0106] Sealing elements are arranged at the contact positions of the plurality of support elements 300 and the plurality of tubular elements 200.

[0107] In the embodiment, when the inside of the outer cladding 100 needs to be heated, the outer cladding 100 is placed on a lathe, and a movable heating source is arranged on the lathe, which can be a graphite heating furnace, an induction heating furnace or a ring-shaped gas torch; the heating temperature of the heating source is 100℃-2300℃; the heating source can be reciprocated on the inner wall of the outer cladding to heat the inside of the outer cladding 100, or the heating source can be reciprocated on the outside of the outer cladding to heat the entire outer cladding 100; by heating the center element 400, the support element 300 and the tubular element 200, the center element 400, the support element 300 and the tubular element 200 can be heated to a semi-molten state to realize fusion of the cutting points.

[0108] By adopting the above technical scheme, the cutting points of the center element 400 and the support element 300 are welded by heating the center element 400, the support element 300 and the tubular element 200, the connection strength between the center element 400 and the support element 300 is improved, the disconnection between the center element 400 and the support element 300 caused by the inflation into the first communication area 500 is prevented, the deformation of the part of the center element 400 corresponding to the support element 300 is prevented, and the consistency of the plurality of first anti-resonance layers 410 in structure is further improved; the cutting points of the plurality of support elements 300 and the plurality of tubular elements 200 are welded, the disconnection between the support element 300 and the tubular element 200 caused by the inflation into the second communication area 700 is prevented, the sealing between the support element 300 and the tubular element 200 is improved, the gas in the second communication area 700 is prevented from leaking into the first communication area 500, and the different inflation pressures in the first communication area 500 and the second communication area 700 are maintained, so as to facilitate the molding of the plurality of first anti-resonance layers 410 and the plurality of second anti-resonance layers 210; the sealing element is arranged at the contact position of the support element 300 and the tubular element 200, so that the sealing element further improves the sealing between the tubular element 200 and the support element 300, further prevents the gas in the second communication area 700 from leaking into the first communication area 500, and further maintains the different inflation pressures in the first communication area 500 and the second communication area 700.

[0109] The sealing element is arranged at the contact position of the plurality of support elements 300 and the plurality of tubular elements 200, including:

[0110] The sealing element is formed by welding quartz at the contact position of the plurality of support elements 300 and the plurality of tubular elements 200.

[0111] In the embodiment, the welding of quartz includes:

[0112] Cleaning the surfaces of the support elements 300 and the tubular elements 200 to be welded to remove dust, oil stains or other contaminants;

[0113] Placing the support elements 300 and the tubular elements 200 to be welded in the correct position and fixing them with clamps;

[0114] Welding using TIG (Tungsten Inert Gas) or other suitable quartz welding technology;

[0115] Melting the quartz welding wire or welding powder by the arc generated by the welding machine and filling it into the contact position of the support element 300 and the tubular element 200;

[0116] During the welding process, protective gas (such as argon or helium) is used to cover the welding area to prevent oxidation of the quartz material;

[0117] Let the quartz material after welding natural cooling or cooling according to process requirements;

[0118] The welding area is polished, polished and other post-processing;

[0119] Leakage test to ensure the sealing between the tubular element 200 and the support element 300.

[0120] By adopting the technical scheme, the contact position of the support element 300 and the tubular element 200 is sealed by adopting the welding of the quartz, and the quartz material has good airtightness. The quartz material has excellent high temperature resistance. The quartz material itself has good chemical stability, and the joint after welding can maintain this stability and resist corrosion and chemical corrosion. Quartz is an excellent optical material, and the welding technology can be used to maintain or restore the optical properties of hollow optical fibers, such as light transmittance and refractive index.

[0121] In combination with FIGS. 4-8, the method for preparing the hollow optical fiber further comprises:

[0122] The number of tubular elements 200 and support elements 300, the inner radius of the outer cladding layer 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:

[0123] Wherein, X is the number of tubular elements 200 and support elements 300, R2 is the inner radius of the outer cladding layer 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.

[0124] 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 layer 100 is greater than the inner radius R2 of the outer cladding layer 100 by 10-35 mm, the inner radius R2 of the outer cladding layer 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.

[0125] 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:

[0126] Wherein, t1 can also be t2, λ m is the resonance wavelength, m is the anti-resonance layer order, and n is the anti-resonance refractive index.

[0127] The following will be further illustrated in connection with specific embodiments:

[0128] In the present embodiment, the inner radius R2 of the outer cladding 100 is set to 25 mm, the outer radius 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 slotting depth of the first slot body 310 and the second slot body 320 is set to 1.5 mm, the distance between the first slot body 310, the second slot body 320 and the end face of the support element 300 is set to 10 mm, the length of the first slot body 310 and the second slot body 320 is set to 15 mm, the distance between the first through hole 221, the second through hole 222 and the end face of the tubular element 200 is set to 10 mm, the radius of the first through hole 221 and the second through hole 222 is set to 0.8 mm, and the radius R1 of the cutting surface is set to 14.6 mm; when inflated, the first inflation microtube is inserted into the second communication area 700 for independent inflation, the second inflation microtube is inserted into the first communication area 500 for independent inflation, and the third inflation microtube is inserted into the inflation area 600 for independent inflation; the inflation pressure of the third inflation microtube is adjusted to 0.5 KPa, the inflation pressure of the first inflation microtube and the inflation pressure of the second inflation microtube are adjusted to 3.5 KPa, so that the part between the two adjacent support elements 300 on the central element 400 is deformed towards the center of the outer cladding 100, and at the same time, six first anti-resonance layers 410 are formed, and the inflation pressure of the first inflation microtube is adjusted to 5.2 KPa, so that the tubular element 200 is deformed towards the first anti-resonance layer 410, thereby simultaneously forming six second anti-resonance layers 420, and the manufacturing of the hollow core optical fiber is realized.

[0129] Through the manufacturing process of the above-mentioned embodiments, five hollow core optical fibers are selected, three of which are arranged with the first slot body 310, the second slot body 320 and the communication hole 220, the hollow core optical fibers arranged with the first slot body 310, the second slot body 320 and the communication hole 220 are serial numbers 1, 2 and 3 in Table 1, the remaining two groups are not arranged with the first slot body 310, the second slot body 320 and the communication hole 220, the hollow core optical fibers not arranged with the first slot body 310, the second slot body 320 and the communication hole 220 are 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 communication hole 220 are inflated by independently inflating the central element 400 and the inflation part of each tubular element 200, and each inflation part is independently inflated by using an inflation microtube to adjust the inflation pressure; by measuring the attenuation values of the light signals at the same position on the five groups of hollow core optical fibers, for example, the attenuation values of the light signals at the position 1550 nm away from the light signal emitting end are shown in Table 1.

[0130] Table 1 Attenuation values at 1550 nm position on hollow core optical fiber

[0131] As can be seen from Table 1, for example, the hollow core optical fiber with fiber serial number 1, the deviation of the radius of the first anti-resonance layer 410 is kept within 0.2 μm, which represents that the plurality of first anti-resonance layers 410 have good consistency in radius, and the deviation of the radius of the second anti-resonance layer 210 is kept within 0.2 μm, which represents that the plurality of 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 kept within 0.1 μm, which represents 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 using the arrangement of the first groove body 310, the second groove body 320 and the communication hole 220, the plurality of first anti-resonance layers 410 and the plurality of first anti-resonance layers 410 have good consistency in radius and wall thickness, and the hollow core optical fiber arranged with the first groove body 310, the second groove body 320 and the communication hole 220 has less attenuation value of optical signal at 1550 nm, which represents that, by using the arrangement of the first groove body 310, the second groove body 320 and the communication hole 220, the loss of the hollow core optical fiber during optical signal transmission is reduced.

[0132] The application provides a hollow core optical fiber, which is produced by the manufacturing method of the hollow core optical fiber according to any one of the above embodiments.

[0133] The manufacturing method of the hollow core optical fiber has been described in detail in the above embodiments, and will not be repeated here.

[0134] By separately inflating the inflation area 600, the first communication area 500 and the second communication area 700, by adjusting the inflation pressure in the first communication area 500 and the second communication area 700 to be equal, and by adjusting the inflation pressure in the inflation area 600 to be less than the inflation pressure in the first communication area 500 and the second communication area 700, the portion between two adjacent support elements 300 on the central element 400 is deformed towards the axis of the outer cladding 100, while forming a plurality of first anti-resonance layers 410, at this time, by adjusting the inflation pressure in the second communication area 700 to be greater than the inflation pressure in the first communication area 500, the tubular element 200 is deformed towards the inside of the first anti-resonance layer 410, thereby simultaneously forming a plurality of second anti-resonance layers 210, by using the arrangement of a plurality of support elements 300, the inflation area 600, the first communication area 500 and the second communication area 700, a plurality of first anti-resonance layers 410 and a plurality of second anti-resonance layers 210 can be formed simultaneously, so that the plurality of first anti-resonance layers 410 remain consistent in structure, the plurality of second anti-resonance layers 210 remain consistent in structure, so that the plurality of deformed first anti-resonance layers 410 can have the same shape, thickness and position, 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 fiber, thereby indirectly reducing the loss of the hollow core fiber when transmitting optical signals.

[0135] Other embodiments of the application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. It is intended that the specification and examples be considered as exemplary only, with the true scope and spirit of the application being indicated by the following claims.

[0136] It is to be understood that the application is not limited to the precise construction described herein and as shown in the attached drawings, and that various modifications and changes can be made by those skilled in the art without departing from the scope of the application. The scope of the application is to be indicated by the appended claims.

Claims

1. A method of manufacturing a hollow core optical fiber, characterized by, The method comprises: arranging a plurality of tubular elements (200) on the inner wall of the outer cladding layer (100) along the circumference of the outer cladding layer (100); arranging support elements (300) between adjacent tubular elements (200) and tangentially connecting the support elements (300) to the tubular elements (200); arranging a central element (400) coaxially with the outer cladding layer (100) in the outer cladding layer (100) and abutting the central element (400) to a plurality of support elements (300); communicating the space between the outer wall of the central element (400), a plurality of tubular elements (200) and a plurality of support elements (300) to form a first communication area (500), and the inside of the central element (400) being an inflation area (600); heating the inside of the outer cladding layer (100); inflating the inflation area (600) and the first communication area (500) separately and adjusting the inflation pressure in the inflation area (600) and the first communication area (500) to deform the central element (400) towards the center of the outer cladding layer (100) to form a plurality of first anti-resonance layers (410) arranged at intervals.

2. The method of manufacturing a hollow core fiber according to claim 1, wherein The method of communicating the space between the outer wall of the central element (400), a plurality of tubular elements (200) and a plurality of support elements (300) to form a first communication area (500) comprises: opening first grooves (310) on the side of the support elements (300) away from the inner wall of the outer cladding layer, and controlling the radial arrangement of the first grooves (310) along the support elements (300) to communicate the space between the outer wall of the central element (400), a plurality of tubular elements (200) and a plurality of support elements (300) through a plurality of first grooves (310) to form a first communication area (500).

3. The method of manufacturing a hollow core fiber according to claim 1, wherein Before the heating of the inside of the outer cladding layer (100), the method comprises: communicating the space between the inner wall of the outer cladding layer (100), a plurality of tubular elements (200) and a plurality of support elements (300) to the inside of a plurality of tubular elements (200) to form a second communication area (700); After the heating of the inside of the outer cladding layer (100), the method comprises: inflating the second communication area (700) separately and adjusting the inflation pressure in the second communication area (700) to deform a plurality of first tubular elements (200) into a plurality of first anti-resonance layers (410) to form a plurality of second anti-resonance layers (210).

4. The method of manufacturing a hollow core fiber according to claim 3, wherein The method of communicating the space between the inner wall of the outer cladding layer (100), a plurality of tubular elements (200) and a plurality of support elements (300) to the inside of a plurality of tubular elements (200) to form a second communication area (700) comprises: opening communication holes (220) through the tubular elements (200) on the tubular elements (200); A second groove (320) is formed on the side of the support element (300) close to the inner wall of the outer cladding layer (100), and the second groove (320) is arranged along the radial direction of the support element (300), so that the space between the inner wall of the outer cladding layer (100), the plurality of tubular elements (200) and the plurality of support elements (300) is communicated with the interiors of the plurality of tubular elements (200) through the plurality of second grooves (320) to form a second communication area (700).

5. The method of manufacturing a hollow core fiber according to any one of claims 1 to 4, characterized in that, Before the central element (400) is arranged coaxially with the outer cladding layer (100) in the outer cladding layer (100), the method comprises: Cutting the plurality of support elements (300) to form a positioning groove (330) on the side of each support element (300) away from the inner wall of the outer cladding layer (100) for accommodating part of the central element (400); Honing, pickling and drying the positioning groove (330).

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

7. The method of manufacturing a hollow fiber according to any one of claims 1 to 4, wherein 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 central element (400) is fused with the plurality of support elements (300) and the plurality of support elements (300) are fused with the plurality of tubular elements (200) at the points of intersection; Sealing elements are arranged at the contact positions of the plurality of support elements (300) and the plurality of tubular elements (200).

8. The method of manufacturing a hollow core fiber according to claim 7, wherein, The sealing of the contact positions of the plurality of support elements (300) and the plurality of tubular elements (200) comprises: Supplementing the sealing elements formed of quartz at the contact positions of the plurality of support elements (300) and the plurality of tubular elements (200).

9. The method of manufacturing a hollow fiber according to any one of claims 1 to 4, wherein The method comprises: controlling the number of the tubular elements (200) and the support elements (300), the inner radius of the outer cladding (100), the outer radius of the tubular elements (200), the outer radius of the central element (400) and the outer radius of the support elements (300) to satisfy the following formula: Wherein X is the number of the tubular elements (200) and the support elements (300), R2 is the inner radius of the outer cladding layer (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).

10. A hollow core optical fiber, characterized by, The hollow core optical fiber is produced by the method for producing a hollow core optical fiber according to any one of claims 1-9.

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