Hollow-core optical fiber with adjustable supporting structure and preparation method of hollow-core optical fiber

Abstract

The invention relates to a hollow-core optical fiber with an adjustable supporting structure and a preparation method thereof.The hollow-core optical fiber comprises an outer cladding and an inner cladding, the inner cladding is composed of anti-resonance structure units, the anti-resonance structure units are arranged in the circumferential direction of the inner wall of the outer cladding, a fiber core is formed by a central cavity wrapped by the inner cladding, each anti-resonance structure unit comprises at least two layers of anti-resonance tubes, and the anti-resonance tubes are arranged in the fiber core. Which comprises an outer anti-resonance tube and an inner anti-resonance tube, and is characterized in that a convex cambered surface is arranged in a region where the outer anti-resonance tube is connected with the inner wall of an outer cladding, and two ends of the convex cambered surface are respectively connected with a stop block arranged between the inner anti-resonance tube and the outer anti-resonance tube; the protruding cambered surface, the check blocks on the two sides and the outer circumferential surface of the inner anti-resonance tube between the check blocks on the two sides form a closed hollow arc-shaped boss, and the protruding cambered surface of the hollow arc-shaped boss is connected with the inner wall of the outer wrapping layer and used for adjusting the distance and direction between the anti-resonance structure unit and the fiber core. According to the invention, the hollow-core optical fiber can maintain good structural characteristics after being drawn, and the transmission performance of the hollow-core optical fiber is improved.

Description

Technical Field

[0001] The invention relates to a hollow-core optical fiber with an adjustable support structure and a preparation method thereof, and belongs to the technical field of optical communication transmission. Background Art

[0002] Currently, widely used solid-core optical fibers are severely limited in many fields due to intrinsic defects in their core quartz matrix materials, such as nonlinearity, dispersion, photodamage, and a lack of transmission in the ultraviolet and mid-infrared bands. This is particularly true in the field of communications and data transmission, where the explosive growth of data traffic and the increasing demands for transmission capacity and speed have severely limited the quality and distance of signal transmission, making it difficult to meet the ever-increasing communication needs. Hollow-core fiber, a key research area in microstructured optical fibers, offers significant advantages, including minimal nonlinearity, low modal dispersion, a high damage threshold, a wide transmission bandwidth, and near-light-speed transmission speeds. These advantages are expected to overcome the bottlenecks of traditional optical fibers and bring new technological solutions to the aforementioned fields. Hollow-core antiresonant fiber, a novel hollow-core fiber, possesses a unique structure that allows the vast majority of light energy (over 99%) to be transmitted within the air core. This significantly reduces the effects of fiber material absorption, reduces nonlinear effects and latency, and improves the damage threshold. This demonstrates significant advantages in flexible transmission of high-power and pulsed lasers, while also providing an efficient platform for light-matter interactions. It holds significant potential for applications in fields such as sensing.

[0003] Even though hollow core fibers have great advantages in theory and application, its transmission loss is always higher than that of traditional quartz optical fiber. In recent years, it has been found that hollow core fibers based on anti-resonant principle can effectively reduce transmission loss under reasonable structural design, and have the potential to be used as ultra-long distance communication optical fibers. In the prior art, such as CN110515152B, a kind of anti-resonant hollow core fiber is disclosed, which comprises a first tubular cladding element, a plurality of second tubular elements and a plurality of third tubular elements, the first tubular cladding element defines an inner cladding surface, the plurality of second tubular elements are attached to the cladding surface and together define a core with an effective radius, the second tubular elements are arranged at intervals, and there is an interval between adjacent second tubular elements, and each of the plurality of third tubular elements is respectively nested in a corresponding second tubular element. The diameter, wall thickness and circumferential arrangement distance of the tubular element need to strictly meet the anti-resonant condition, but it is difficult to avoid micron-level size deviation in actual manufacturing. The fluctuation of the wall thickness of the tubular element will cause a significant reduction in the transmission bandwidth of the hollow core fiber. Since the patent is formed by nesting and assembling the anti-resonant structure through multiple layers of tubular elements, each tubular element is in direct contact, so the contact points of the tubular elements will produce uncontrollable adhesion during the drawing process, causing uneven wall thickness near the contact points. Especially in the drawing of long-distance hollow core fibers, it is difficult to maintain good consistency along the length direction of the fiber structure, thereby affecting the transmission attenuation and bandwidth of the hollow core fiber. At the same time, the anti-resonant ring is often attached to the cladding tube after the drawing process, so that the high-order mode is not easy to be coupled from the core to the cladding tube, causing the single-mode characteristic to be deteriorated. SUMMARY

[0004] The problem to be solved by the present application is to provide a kind of adjustable support structure hollow core fiber and its preparation method to solve the problems existing in the prior art, so that the hollow core fiber can maintain good structural characteristics after drawing, and improve the transmission performance of the hollow core fiber.

[0005] The hollow core fiber technical scheme adopted by the present application to solve the above-mentioned problems is as follows: it comprises an outer cladding layer and an inner cladding layer, the inner cladding layer is composed of anti-resonant structure units, the anti-resonant structure units are arranged along the circumference of the inner wall of the outer cladding layer and are in contact with the inner wall of the outer cladding layer, the central cavity covered by the inner cladding layer forms a core, the anti-resonant structure unit comprises at least two layers of anti-resonant tubes, including one outer anti-resonant tube and one inner anti-resonant tube, characterized in that the area where the outer anti-resonant tube is in contact with the inner wall of the outer cladding layer is provided with a convex arc surface, the two ends of the convex arc surface are respectively in contact with the stop blocks arranged between the inner and outer anti-resonant tubes, so that the convex arc surface and the two side stop blocks and the outer circumferential surface of the inner anti-resonant tube between the two side stop blocks form a closed hollow arc-shaped boss, the convex arc surface of the hollow arc-shaped boss is in contact with the inner wall of the outer cladding layer, which is used to adjust the distance and orientation of the anti-resonant structure unit and the core.

[0006] According to the above scheme, the blocking pieces on both sides of the hollow arc-shaped boss are arranged in the radial direction, and the central angle θ formed by the line connecting the two blocking pieces and the center of the fiber core is less than or equal to 120°. Further, it is less than or equal to 90°, and further less than or equal to 60°.

[0007] According to the above scheme, the hollow arc-shaped boss is in a symmetrical structure in the radial direction, and the convex arc surface is composed of one or more arc surfaces, and the distance d between the highest point of the convex arc surface and the fitting circle of the outer anti-resonance tube wall is 1-15 μm. Further, it is 3-10 μm.

[0008] According to the above scheme, the anti-resonance structure unit is 4-6, and the anti-resonance structure unit includes 2-4 anti-resonance tubes, including one outer anti-resonance tube and one or more inner anti-resonance tubes.

[0009] According to the above scheme, the inner wall of the outer cladding is circular, the anti-resonance structure unit includes one circular outer anti-resonance tube and one or two circular inner anti-resonance tubes with different radii, and the area where the circular outer anti-resonance tube is connected with the inner wall of the outer cladding is provided with a convex arc surface, and the hollow arc-shaped boss is formed by the convex arc surface and the adjacent first circular inner anti-resonance tube.

[0010] According to the above scheme, the first circular inner anti-resonance tube is sleeved with a second circular inner anti-resonance tube, and the second circular inner anti-resonance tube is tangent to the first circular inner anti-resonance tube.

[0011] According to the above scheme, a radial intermediate blocking piece is arranged in the hollow arc-shaped boss, and the hollow arc-shaped boss is divided into two separate closed cavities.

[0012] According to the above scheme, the outer diameter of the outer cladding is 100-500 μm.

[0013] According to the above scheme, the outer diameter of the outer anti-resonance tube is 20-60 μm.

[0014] According to the above scheme, the outer diameter of the first circular inner anti-resonance tube is 10-50 μm.

[0015] According to the above scheme, the outer diameter of the second circular inner anti-resonance tube is 4-40 μm.

[0016] According to the above scheme, the fundamental mode transmission loss of the hollow core optical fiber is less than or equal to 1 dB / km. Further, it is less than or equal to 0.1 dB / km.

[0017] According to the above scheme, the 3 dB bandwidth of the hollow core optical fiber is greater than or equal to 100 nm.

[0018] According to the above scheme, the minimum high-order mode transmission loss of the hollow core optical fiber is greater than or equal to 100 dB / km.

[0019] According to the scheme, the minimum high-order mode transmission loss of the hollow core optical fiber is greater than or equal to 1000 dB / km.

[0020] According to the scheme, the minimum high-order mode transmission loss of the hollow core optical fiber is greater than or equal to 5000 dB / km.

[0021] The technical scheme of the preparation method of the hollow core optical fiber is: The anti-resonant structure unit preform is prepared, glass tubes with different radii are sleeved into a nested structure, and fixed blocks are arranged in the inner and outer nested tubes to form closed cavities in each nested tube, The outer cladding glass sleeve is prepared, and the glass sleeve used as the outer cladding is prepared according to the corresponding size ratio of the anti-resonant structure unit preform, The hollow core optical fiber preform is prepared, the anti-resonant structure unit preform is loaded and fixed in the inner hole wall of the outer cladding glass tube, and then heated and fused at one end to form a hollow core optical fiber preform, The fiber is drawn, and the hollow core optical fiber preform is clamped to the optical fiber drawing furnace to draw the hollow core optical fiber.

[0022] According to the scheme, during the drawing process of the optical fiber, the multiple closed cavity regions formed by the anti-resonant structure unit are filled with different pressure gases to ensure that the structure of the drawn optical fiber meets the expectation, and the closed cavity region of the hollow arc-shaped boss is filled with a higher pressure gas than other closed cavity regions of the anti-resonant structure unit, so as to form the convex arc surface of the hollow arc-shaped boss.

[0023] According to the scheme, a radial middle block is arranged in the middle of the hollow arc-shaped boss to separate the hollow arc-shaped boss into two separate closed cavity regions, and the two separate closed cavity regions are filled with different pressure gases, so that the swing angle of the anti-resonant unit can be adjusted during the drawing process, thereby adjusting the spacing between the anti-resonant units.

[0024] The beneficial effects of the present application are: 1. By arranging the hollow arc-shaped boss, the inner and outer anti-resonance tubes can be spaced apart and the spacing can be adjusted, so that not only the tube wall adhesion phenomenon easily occurring in the manufacturing process of the anti-resonance structure unit of the hollow core optical fiber is reduced, thereby avoiding the problem of uneven wall thickness of the manufactured hollow core optical fiber, but also the spacing between the inner and outer anti-resonance tubes can be adjusted to a more appropriate spacing, so that the hollow core optical fiber can maintain good structural characteristics after drawing. 2. The protruding height of the hollow arc-shaped boss can be dynamically adjusted by pressure adjustment during drawing, so as to adjust the spacing and orientation of the anti-resonance structure unit and the core, and also increase the spacing between the anti-resonance structure element and the inner wall of the outer cladding, so that the high-order mode of the core can be better coupled in the cladding, thereby reducing the loss of the fundamental mode and improving the high-order mode loss, thereby improving and optimizing the transmission performance of the hollow core optical fiber. 3. The present application arranges a radial middle stopper in the middle of the hollow arc-shaped boss, which divides the hollow arc-shaped boss into two separate closed cavities. Different air pressures can be introduced into the two closed spaces during drawing, so as to change the swing angle of the anti-resonance structure unit, so that the spacing between the anti-resonance structure units is more uniform, and the error of the spacing can be controlled within ±10%, so as to improve the manufacturing precision of the hollow core optical fiber. The present application has higher manufacturing error tolerance in the production and manufacturing process, and is more suitable for the preparation of low-loss, large-bandwidth and long-distance hollow core optical fiber. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a radial structure schematic diagram of an embodiment of the present application.

[0026] Figure 2 is Figure 1 is an enlarged structural schematic diagram of the anti-resonance structure unit.

[0027] Figure 3 is a radial structure schematic diagram of a second embodiment of the present application.

[0028] Figure 4 is Figure 3 is an enlarged structural schematic diagram of the anti-resonance structure unit.

[0029] Figure 5 is a radial structure schematic diagram of a third embodiment of the present application.

[0030] Figure 6 is Figure 5 is an enlarged structural schematic diagram of the anti-resonance structure unit.

[0031] Figure 7 is a radial structure schematic diagram of a fourth embodiment of the present application.

[0032] Figure 8 is Figure 7 is an enlarged structural schematic diagram of the anti-resonance structure unit.

[0033] Figure 9 is a schematic diagram of a radial structure of the fifth embodiment of the present application.

[0034] Figure 10 is Figure 9 is a schematic diagram of an enlarged structure of the anti-resonance structure unit in the fifth embodiment of the present application.

[0035] Figure 11 is a schematic diagram of the anti-resonance structure unit before and after the angle adjustment in the fifth embodiment of the present application. DETAILED DESCRIPTION

[0036] The present application will be further described in detail below in conjunction with the accompanying drawings and examples.

[0037] The first embodiment of the present application is shown in Figure 1 , Figure 2As shown, it includes an outer cladding 2 and an inner cladding, the outer cladding is circular, the outer diameter of the outer cladding is 225μm, the inner cladding is composed of five anti-resonance structural units 3, each anti-resonance structural unit has the same structure and is evenly distributed along the circumference of the inner wall of the outer cladding, and is connected to the inner wall of the outer cladding. The central cavity covered by the inner cladding forms a fiber core, and the anti-resonance structural unit includes two layers of anti-resonance tubes, including a circular outer anti-resonance tube 301 and a circular inner anti-resonance tube 302. The outer diameter of the circular outer anti-resonance tube is 33μm, the outer radius of the circular inner anti-resonance tube is 21μm, and the wall thickness of the inner and outer anti-resonance tubes is 1.15±0.15μm. The area where the circular outer anti-resonance tube connects to the inner wall of the outer cladding is provided with a convex arc surface 5 01, the two ends of the raised arc surface are respectively connected to the two side blocks 401 and 402 installed between the inner and outer anti-resonance tubes. The blocks on both sides are installed radially, and the central angle θ formed by the line connecting the two side blocks and the center of the fiber core is 120°, so that the raised arc surface and the two side blocks and the outer peripheral surface of the inner anti-resonance tube between the two side blocks form a closed hollow arc-shaped boss. The hollow arc-shaped boss is a closed cavity B1. The hollow arc-shaped boss is a radially symmetrical structure. The raised arc surface is composed of an arc surface. The distance d between the highest point of the bulge and the fitting circle of the outer anti-resonance tube wall is 8.7μm, which reduces the distance between the anti-resonance structure unit and the fiber core by 8.7μm. The raised arc surface of the hollow arc-shaped boss is tangent to the inner wall of the outer cladding. During the optical fiber drawing process, the three closed cavity areas A1, A2, and B1 formed by the anti-resonance structure unit are filled with gases of different pressures to ensure that the optical fiber structure after drawing meets the expectations. The gas pressure entering B1 is greater than the gas pressure entering A1 and A2. The enclosed space B1 bulges after drawing, forming a convex arc surface. The minimum spacing between each antiresonance structure unit 3 is maintained in the range of 5.0±0.7μm, thereby forming the hollow-core optical fiber 1 with an adjustable support structure of this embodiment. The outer cladding, inner and outer antiresonance tubes, and blocks in this embodiment are all made of pure silica. The hollow-core optical fiber has an attenuation of 0.13dB / km@1550nm, and its minimum high-order mode transmission loss is 873dB / km.

[0038] The second embodiment of the present invention is Figure 3 、 Figure 4As shown in the figure, the main difference between this embodiment and the previous one is that the anti-resonance structure unit comprises three layers of anti-resonance tubes, including one circular outer anti-resonance tube 301 and two circular inner anti-resonance tubes, i.e., a first circular inner anti-resonance tube 302 and a second circular inner anti-resonance tube 303. The outer diameter of the circular outer anti-resonance tube is 30 μm, the outer radius of the first circular inner anti-resonance tube is 22 μm, and the outer radius of the second circular inner anti-resonance tube is 9 μm. The wall thickness of each anti-resonance tube is 1.13 ± 0.18 μm. The two ends of the convex arc surface 501 are respectively connected to the two side blocks 401 and 402 arranged between the inner and outer anti-resonance tubes. The two side blocks are arranged along the radial direction, and the circular central angle θ formed by the connecting line between the two side blocks and the center of the fiber core is 115°. The five anti-resonance structure units 3 are structurally identical and uniformly distributed along the circumferential direction of the inner wall of the outer cladding and are connected to the inner wall of the outer cladding. The minimum distance between the anti-resonance structure units is kept in the range of 4.3 ± 0.8 μm. The outer cladding is circular, and the outer diameter of the outer cladding is 235 μm. In the drawing process, the four closed areas A1, A2, A3, and B1 formed by the anti-resonance structure units are connected to different pressure gases to ensure that the structure of the drawn fiber meets the expectations. The pressure of the gas connected to B1 is greater than that of the gas connected to A1 and A2. The closed space B1 is convex after drawing, forming a convex arc surface 501. The distance d between the highest point of the convex arc surface 501 and the fitting circle of the outer anti-resonance tube wall is 9.8 μm. The other structures are the same as those of the previous embodiment. The hollow core fiber 1 in this embodiment has an attenuation of 0.10 dB / km @ 1550 nm, and the minimum high-order mode transmission loss is 1033 dB / km.

[0039] The third embodiment of the present application is shown in the figure. Figure 5 , Figure 6 The main difference between this embodiment and the second embodiment is that the outer diameter of the circular outer anti-resonance tube is 37 μm, the outer radius of the first circular inner anti-resonance tube is 25 μm, the outer radius of the second circular inner anti-resonance tube is 11 μm, the wall thickness of each anti-resonance tube is 1.16 ± 0.17 μm, and the outer diameter of the outer cladding is 265 μm. The two ends of the convex arc surface 501 are respectively connected to the two side blocks 401 and 402 arranged between the inner and outer anti-resonance tubes. The two side blocks are arranged along the radial direction, and the circular central angle θ formed by the connecting line between the two side blocks and the center of the fiber core is 68°. The distance d between the highest point of the convex arc surface 501 and the fitting circle of the outer anti-resonance tube wall is 2.2 μm. The minimum distance between the anti-resonance structure units is kept in the range of 4.8 ± 0.7 μm. The hollow core fiber 1 in this embodiment has an attenuation of 0.12 dB / km @ 1550 nm, and the minimum high-order mode transmission loss is 238 dB / km.

[0040] The fourth embodiment of the present application is shown in the figure. Figure 7 , Figure 8As shown, the main difference from the second embodiment is that the outer diameter of the circular outer antiresonance tube is 35μm, the outer radius of the first circular inner antiresonance tube is 21μm, and the outer radius of the second circular inner antiresonance tube is 9μm. The wall thickness of the inner and outer antiresonance tubes is 1.12±0.12μm, and the outer diameter of the outer cladding is 230μm. The two ends of the convex arc surface 501 are respectively connected to the two side blocks 401 and 402 installed between the inner and outer antiresonance tubes. The two side blocks are installed radially, and the central angle θ formed by the line connecting the two side blocks and the center of the fiber core is 108°. The convex arc surface is composed of three arc surfaces, the middle arc surface has a larger curvature radius, and the two side arc surfaces have a smaller curvature radius, forming an oblate convex arc surface. The distance d between the highest point of the convex arc surface 501 and the fitting circle of the outer antiresonance tube wall is 5.3μm. The minimum spacing between each antiresonance structural unit is maintained in the range of 4.4±0.6μm. The hollow-core optical fiber 1 of this embodiment has an attenuation of 0.08 dB / km@1550 nm, and its minimum high-order mode transmission loss is 1869 dB / km.

[0041] The fifth embodiment of the present invention is Figure 9 、 Figure 10 、 Figure 11 As shown, the main difference between it and the fourth embodiment is that the outer diameter of the circular outer antiresonance tube is 34μm, the outer radius of the first circular inner antiresonance tube is 20μm, and the outer radius of the second circular inner antiresonance tube is 10μm. The wall thickness of the inner and outer antiresonance tubes is 1.18±0.11μm, and the outer diameter of the outer cladding is 244μm. The two ends of the convex arc surface 501 are respectively connected to the two side blocks 401 and 402 arranged between the inner and outer antiresonance tubes. The two side blocks are arranged radially, and the central angle θ formed by the line connecting the two side blocks and the center of the fiber core is 117°. A radial intermediate block 403 is provided in the middle of the hollow arc-shaped boss to separate the hollow arc-shaped boss into two separate closed cavities B1 and B2. The minimum spacing between each antiresonance structural unit is maintained in the range of 4.8±0.3μm. During the drawing process, the five closed areas A1, A2, A3, B1, and B2 formed by the anti-resonance unit are filled with gas without pressure to ensure that the fiber structure after drawing meets the expectations. There will be certain geometric errors in the preparation process of hollow-core fiber, which will cause the anti-resonance structure unit to have a certain inclination angle, such as Figure 11 As shown, by introducing gases of different pressures into enclosed areas B1 and B2, the swing angle of the antiresonance units 3 can be adjusted during the drawing process, with the centerline swinging from Z1 to Z2, thereby optimizing the spacing between the antiresonance units 3. The hollow-core fiber 1 of this embodiment has an attenuation of 0.06 dB / km at 1550 nm, and a minimum high-order mode transmission loss of 716 dB / km.

Claims

1. A hollow-core optical fiber with an adjustable support structure, comprising an outer cladding and an inner cladding, wherein the inner cladding is composed of antiresonance structural units, the antiresonance structural units being arranged along the circumference of the inner wall of the outer cladding and in contact with the inner wall of the outer cladding, the central cavity covered by the inner cladding forming a fiber core, the antiresonance structural units comprising at least two layers of antiresonance tubes, including an outer antiresonance tube and an inner antiresonance tube, characterized in that A convex arc surface is provided in the area where the outer anti-resonance tube connects to the inner wall of the outer cladding. The two ends of the convex arc surface are respectively connected to the stoppers arranged between the inner and outer anti-resonance tubes, so that the convex arc surface and the stoppers on both sides and the outer peripheral surface of the inner anti-resonance tube between the stoppers on both sides form a closed hollow arc-shaped boss. The convex arc surface of the hollow arc-shaped boss is connected to the inner wall of the outer cladding, so as to adjust the spacing and orientation between the anti-resonance structural unit and the fiber core.

2. The adjustable support structure hollow-core optical fiber according to claim 1, characterized in that The stoppers on both sides of the hollow arc-shaped boss are arranged radially, and the central angle θ formed by the lines connecting the stoppers on both sides and the center of the fiber core is less than or equal to 120°.

3. The hollow-core optical fiber with adjustable support structure according to claim 1 or 2, characterized in that The hollow arc-shaped boss is symmetrical in the radial direction. The raised arc surface is composed of one or several arc surfaces. The distance d between the highest point of the projection and the fitting circle of the outer anti-resonance tube wall is 1-15 μm.

4. The hollow-core optical fiber with adjustable support structure according to claim 1 or 2, characterized in that There are 4 to 6 anti-resonance structural units, and the anti-resonance structural units include 2 to 4 anti-resonance tubes, including 1 external anti-resonance tube and 1 or more internal anti-resonance tubes.

5. The hollow-core optical fiber with adjustable support structure according to claim 1 or 2, characterized in that The inner wall of the outer cladding is circular, and the anti-resonance structure unit includes a circular outer anti-resonance tube and 1 to 2 circular inner anti-resonance tubes with different radii. The area where the circular outer anti-resonance tube connects to the inner wall of the outer cladding is provided with a convex arc surface, which forms a hollow arc-shaped boss with the adjacent first circular inner anti-resonance tube.

6. The hollow-core optical fiber with adjustable support structure according to claim 5, characterized in that A second circular inner anti-resonance tube is sleeved in the first circular inner anti-resonance tube, and the second circular inner anti-resonance tube is tangent to the first circular inner anti-resonance tube.

7. The hollow-core optical fiber with adjustable support structure according to claim 1 or 2, characterized in that A radial middle stopper is provided in the middle of the hollow arc-shaped boss to separate the hollow arc-shaped boss into two separate closed cavities.

8. The hollow-core optical fiber with adjustable support structure according to claim 5, characterized in that The outer diameter of the outer cladding layer is 100-500 μm.

9. The hollow-core optical fiber with adjustable support structure according to claim 6, characterized in that The outer diameter of the external anti-resonance tube is 20-60 μm.

10. The hollow-core optical fiber with adjustable support structure according to claim 6, characterized in that The outer diameter of the first circular inner anti-resonance tube is 10-50 μm.

11. The hollow-core optical fiber with adjustable support structure according to claim 6, characterized in that The outer diameter of the second circular inner anti-resonance tube is 4-40 μm.

12. The hollow-core optical fiber with adjustable support structure according to claim 1 or 2, characterized in that The fundamental mode transmission loss of the hollow core optical fiber is less than or equal to 1 dB / km.

13. The hollow-core optical fiber with adjustable support structure according to claim 1 or 2, characterized in that The 3dB bandwidth of the hollow-core optical fiber is greater than or equal to 100nm.

14. The hollow-core optical fiber with adjustable support structure according to claim 1 or 2, characterized in that The minimum high-order mode transmission loss of hollow-core optical fiber is greater than or equal to 100dB / km.

15. A method for preparing a hollow-core optical fiber with an adjustable support structure according to any one of claims 1 to 14, characterized in that Prepare the anti-resonance structure unit preform, put glass tubes of different radii into a nested structure, and install fixed blocks in the inner and outer nested tubes to form a closed cavity in each nested tube. Prepare the outer cladding glass sleeve, and prepare the glass sleeve used as the outer cladding according to the size ratio corresponding to the anti-resonance structure unit prefabricated part. Prepare the hollow core optical fiber preform rod, install the anti-resonance structure unit preform into the inner hole wall of the outer cladding glass tube according to the orientation and fix it, then heat and melt the cone at one end to make the hollow core optical fiber preform rod. Drawing into fiber: The hollow-core optical fiber preform is clamped into the optical fiber drawing furnace and drawn into a hollow-core optical fiber.

16. The method for preparing a hollow-core optical fiber with an adjustable support structure according to claim 15, characterized in that During the optical fiber drawing process, gases of different pressures are introduced into the multiple closed cavity areas formed by the anti-resonance structural unit to ensure that the optical fiber structure after drawing meets expectations. The closed cavity area of ​​the hollow arc-shaped boss is introduced with gas of higher pressure than other closed cavity areas of the anti-resonance structural unit to form the convex arc surface of the hollow arc-shaped boss.

17. The method for preparing a hollow-core optical fiber with an adjustable support structure according to claim 15 or 16, characterized in that A radial intermediate stopper is provided in the middle of the hollow arc-shaped boss to separate the hollow arc-shaped boss into two separate closed cavity areas. Gases of different pressures are introduced into the two separate closed cavity areas, and the swing angle of the anti-resonance unit is adjusted during the wire drawing process, thereby adjusting the spacing between the anti-resonance units.

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