Low-loss hollow-core anti-resonance optical fiber

Abstract

The invention provides a low-loss hollow-core anti-resonance optical fiber. The low-loss hollow-core anti-resonance optical fiber comprises an outer wrapping layer, a plurality of anti-resonance units arranged in the outer wrapping layer and a fiber core area defined by the anti-resonance units. The anti-resonance units are circumferentially arranged around the central axis of the outer cladding; each anti-resonance unit comprises a nested structure unit and a support structure for providing support for the nested structure unit, one end of each support structure is connected with the nested structure unit, and the other end of each support structure is connected with the inner wall of the outer cladding. By designing the layout mode of the anti-resonance units in the air fiber core unit, the target light beam is transmitted in the fiber core area with low loss, and the transmission capacity of the hollow-core anti-resonance optical fiber is improved.

Description

Technical Field

[0001] This invention relates to the fields of optics and laser optoelectronics, and more particularly to a low-loss hollow-core anti-resonant optical fiber. Background Technology

[0002] Hollow-core antiresonant fiber achieves light guidance through an antiresonant reflection waveguide mechanism, the core of which is confining the light field within a low-refractive-index air core. Currently, hollow-core antiresonant fibers typically utilize a periodic thin-walled capillary structure surrounding the hollow core to generate an antiresonant effect, confining light transmission within the air core while suppressing light leakage into the cladding material. However, non-ideal losses introduced by the fiber's microstructure (such as capillary shape, wall thickness uniformity, and mode coupling) mean that current transmission losses are still significantly higher than the theoretical limit. Therefore, further optimizing the fiber's microstructure to reduce transmission loss is a critical bottleneck that urgently needs to be addressed in current technology.

[0003] Therefore, there is potential to further reduce the loss of optical fibers, and existing technologies need further improvement. Summary of the Invention

[0004] The purpose of this invention is to provide a low-loss hollow-core anti-resonant optical fiber, and to achieve ultra-low transmission loss of the hollow-core anti-resonant optical fiber by designing a novel optical fiber structure.

[0005] The technical solution adopted by this invention to solve the technical problem is as follows: This application provides a low-loss hollow-core anti-resonant optical fiber, comprising: an outer cladding layer and a plurality of anti-resonant units disposed within the outer cladding layer and a core region enclosed by each of the anti-resonant units; the anti-resonant units are arranged circumferentially around the central axis of the outer cladding layer; Each of the anti-resonance units includes a nested structural unit and a support structure for providing support for the nested structural unit. One end of each support structure is connected to the nested structural unit, and the other end is connected to the inner wall of the outer cladding.

[0006] Optionally, each anti-resonant unit is arranged at equal or non-equal angle intervals along the inner wall of the outer cladding, and there is a preset gap between two adjacent anti-resonant units.

[0007] Optionally, the support structure includes one or more support units, each support unit being a straight structure, a curved structure, or a hybrid structure composed of straight lines and curves.

[0008] Optionally, the support unit is one or more glass rods; when the support unit is linear and contains multiple glass rods, the glass rods are arranged side by side; when the support unit is curved, the curvature of the curved glass rods corresponding to each anti-resonance unit is kept consistent, or the curvature of the curved glass rods corresponding to each adjacent anti-resonance unit is arranged opposite to each other.

[0009] Optionally, the anti-resonance unit contains one nested structural unit, and each nested structural unit is connected to two supporting units, which are in a linear shape. The two supporting units have a certain tilt angle relative to each other, and one end of the two supporting units is attached to the nested structural unit, while the other end is connected to the inner wall of the outer cladding layer.

[0010] Optionally, the nested structural unit includes a single layer or multiple layers of nested circular glass tubes with different radii, and the radii of each nested circular glass tube increase or decrease sequentially, with the centers of the tubes on the same straight line, forming an eccentric nested structure, and each nested circular glass tube is connected to the corresponding support structure of its nested structural unit.

[0011] Optionally, an anti-resonance layer is provided between each of the anti-resonance units; the anti-resonance layer is connected to the inner wall of the outer cladding layer, or the anti-resonance layer is connected to the support structure.

[0012] Optionally, the anti-resonant layer may be in the shape of an arc, circle, fan, ellipse, or polygon.

[0013] Optionally, the anti-resonant layer is a single-layer or multi-layer structure, and the thickness of the anti-resonant layer and the thickness of the nested structural unit are configured to satisfy the anti-resonant reflection light guiding condition at the target wavelength.

[0014] Optionally, the material of each anti-resonance layer and each anti-resonance unit is silicon dioxide; and the thickness of the anti-resonance layer satisfies the following formula: ; Where m is a natural number. For transmission wavelength, It is the refractive index of silicon dioxide. It is the refractive index of the air in the fiber core.

[0015] Beneficial effects: This embodiment provides a low-loss hollow-core anti-resonant optical fiber, comprising: an outer cladding, a plurality of anti-resonant units disposed within the outer cladding, and a core region enclosed by each anti-resonant unit; each anti-resonant unit is arranged circumferentially around the central axis of the outer cladding; each anti-resonant unit includes a nested structural unit and a support structure for supporting the nested structural unit, one end of each support structure being connected to the nested structural unit, and the other end being connected to the inner wall of the outer cladding. This invention, by designing the layout of the anti-resonant units within the air-core unit, achieves low-loss transmission of the target beam in the core region, thereby improving the transmission capability of the hollow-core optical fiber. Attached Figure Description

[0016] Figure 1 A schematic diagram of the radial cross-section of the first embodiment of the low-loss hollow anti-resonant optical fiber provided by the present invention; Figure 2 A schematic diagram of the radial cross-section of the second embodiment of the low-loss hollow antiresonant optical fiber provided by the present invention; Figure 3 A schematic diagram of the radial cross-section of the third embodiment of the low-loss hollow antiresonant optical fiber provided by the present invention; Figure 4 A schematic diagram of the radial cross-section of the fourth embodiment of the low-loss hollow antiresonant optical fiber provided by the present invention; Figure 5 A schematic diagram of the radial cross-section of the fifth embodiment of the low-loss hollow-core antiresonant optical fiber provided by the present invention; Figure 6 A schematic diagram of the radial cross-section of the sixth embodiment of the low-loss hollow antiresonant optical fiber provided by the present invention; Figure 7 The loss curve of the low-loss hollow anti-resonant optical fiber according to the first embodiment of the present invention; Figure 8 The loss curve of the low-loss hollow anti-resonant optical fiber according to the second embodiment of the present invention; Figure 9 This is the loss curve of the low-loss hollow anti-resonant optical fiber in the third embodiment of the present invention. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0018] Other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein.

[0019] Fiber optic technology is a crucial pillar in modern optical communication, fiber optic sensing, and high-power laser transmission. Traditional solid-core optical fibers (such as silica fibers) mainly rely on total internal reflection to guide light. However, due to limitations such as the nonlinear effects of silica materials and internal dispersion in optical fibers, further optimization of the transmission characteristics of solid-core single-mode optical fibers faces challenges.

[0020] With the rapid development of technologies such as 5G / 6G, cloud computing, the Internet of Things, and artificial intelligence, unprecedented demands are being placed on the transmission capacity, speed, and latency of communication systems. The performance of traditional solid-core silica optical fibers (such as single-mode fiber SMF) is gradually approaching its physical limits, particularly in terms of nonlinear effects and transmission delay, which restricts further increases in system capacity. Hollow-core optical fibers, due to their unique transmission characteristics in air or vacuum, are considered a key technology for overcoming the bottlenecks of traditional optical fibers. Their core advantages lie in extremely low nonlinearity, ultra-low latency, and potentially low transmission loss, thus hollow-core optical fibers have potential application value in long-distance optical communication. Therefore, hollow-core optical fibers have wider applications in optical fiber communication, high-precision interferometric sensing, and high-power laser transmission.

[0021] Hollow-core antiresonant fiber is currently one of the mainstream structures for achieving high-performance hollow-core optical transmission. Its basic principle is to utilize the antiresonance effect generated by the periodic thin-walled capillary structure surrounding the hollow core to confine light transmission within the air core, while simultaneously suppressing light leakage into the cladding material. However, the core challenge facing existing hollow-core antiresonant fiber technology is that transmission loss remains significantly higher than theoretically expected. The high transmission loss is mainly caused by several factors, including: when using air as the transmission medium, gas molecules generate absorption peaks at specific wavelengths, leading to increased loss; the difficulty in achieving perfectly uniform wall thickness in hollow-core antiresonant fibers, resulting in the antiresonance condition not being perfectly satisfied at all locations, thus increasing transmission loss; and in actual transmission, minute deformations in the fiber core structure can cause the fundamental mode to couple with other higher-order modes. Higher-order modes typically have higher losses, therefore coupling with higher-order modes leads to an increase in overall transmission loss. Therefore, a novel low-loss hollow-core antiresonant fiber design is urgently needed to more effectively suppress key loss mechanisms while maintaining a relatively simple structure to meet the practical needs of next-generation high-speed, high-capacity, low-latency optical communication systems and other demanding applications.

[0022] To overcome the problems existing in hollow-core optical fibers in the prior art, this invention provides a low-loss hollow-core anti-resonant optical fiber. The low-loss hollow-core anti-resonant optical fiber provided by this invention includes: an outer cladding, a plurality of anti-resonant units disposed within the outer cladding, and a core region enclosed by each anti-resonant unit; each anti-resonant unit is arranged circumferentially around the central axis of the outer cladding; each anti-resonant unit includes a nested structural unit and a support structure for supporting the nested structural unit, with one end of each support structure connected to the nested structural unit and the other end connected to the inner wall of the outer cladding. The hollow-core anti-resonant optical fiber provided by this invention, through the layout of the anti-resonant units and the support structures within the anti-resonant units, achieves a relatively simple anti-resonant optical fiber structure, which helps reduce light scattering and absorption during transmission, improves transmission efficiency, reduces transmission loss, and enhances the reliability of the optical fiber.

[0023] The following is a detailed description of a low-loss hollow anti-resonant optical fiber provided in this embodiment, with reference to the accompanying drawings.

[0024] This application provides a low-loss hollow-core anti-resonant optical fiber, such as Figure 1 The diagram shown is a schematic diagram of the radial cross-section of the optical fiber provided in this embodiment. The hollow anti-resonant optical fiber includes: an outer cladding layer 1 and a plurality of anti-resonant units 2 disposed within the outer cladding layer 1 and a fiber core region 3 enclosed by each of the anti-resonant units 2; each anti-resonant unit 20 is arranged circumferentially around the central axis of the outer cladding layer 1.

[0025] Each of the anti-resonance units 2 includes a nested structure unit 21 and a support structure 22 for providing support for the nested structure unit 22. One end of each support structure 22 is connected to the nested structure unit 21, and the other end is connected to the inner wall of the outer cladding layer 1.

[0026] like Figure 1 As shown, the outer cladding 1 of the low-loss hollow-core anti-resonant optical fiber provided in this application is located on the outermost layer, is in the shape of a ring, and has a uniform thickness. Multiple anti-resonant units 2 are disposed inside the outer cladding 1, and a core region 3, formed by multiple anti-resonant units 2 and located at the center of the optical fiber, is formed by these units. Each anti-resonant unit 2 is connected to the inner wall of the outer cladding 1. Figure 1 Each anti-resonant unit 2 is arranged circumferentially around the central axis of the outer cladding layer. In specific implementation, each anti-resonant unit 2 is arranged at equal angular intervals or non-equal angular intervals along the inner wall of the outer cladding layer 1. There is a preset gap between two adjacent anti-resonant units 2. The gap between two adjacent anti-resonant units 2 can be a fixed value (that is, each anti-resonant unit is arranged at equal angular intervals) or a non-fixed value (that is, each anti-resonant unit is arranged at non-equal angular intervals).

[0027] Furthermore, each anti-resonant unit has an identical structure, including at least one nested structural unit 21 and a support structure 22 for supporting the nested structural unit 21. One end of the support structure is connected to the nested structural unit to support it, and the other end is connected to the inner wall of the outer cladding layer, ensuring the stability of the nested structural unit. The number of anti-resonant units is greater than or equal to three.

[0028] The nested structural unit comprises one or more nested circular glass tubes with different radii, wherein the radii of each nested circular glass tube increase or decrease sequentially, and their centers lie on the same straight line, forming an eccentric nested structure. Each nested circular glass tube is connected to a corresponding support structure of its nested structural unit. The nested structural unit as a whole exhibits a symmetrical structure. Figure 1 As shown, the nested structure unit 21 includes two nested circular glass tubes. The smaller-radius nested circular glass tube is located inside the larger-radius nested circular glass tube. The connection point between the smaller-radius and larger-radius nested circular glass tubes coincides with the connection point between the larger-radius nested circular glass tube and the support structure. One end of the support structure is connected to the nested circular glass tubes, and the other end is connected to the outer cladding layer. The support structure is a slender rod-shaped structure, making the structure of each anti-resonant unit resemble a "lollipop" structure. Since the overall shape of each anti-resonant unit provided in this embodiment is a "lollipop" structure, with its front end forming the fiber core region and its rear end connected to the outer cladding layer, the distance between the outer cladding layer and the fiber core region can be effectively increased, thereby further reducing losses.

[0029] Furthermore, an anti-resonance layer is disposed between each of the anti-resonance units; the anti-resonance layer is connected to the inner wall of the outer cladding layer. For example... Figure 2 As shown, the anti-resonance layer 4 is located between two adjacent anti-resonance units 2 and is attached to the inner wall of the outer cladding layer 1. The anti-resonance layer 4 has a certain thickness, and the thickness needs to meet certain conditions to satisfy the anti-resonance reflection and light guiding conditions.

[0030] In practical implementation, depending on the application scenario, the shape of the anti-resonance layer can be set as an arc, circle, fan, ellipse, or polygon structure as needed. The symmetrical structures of the above-mentioned shapes can achieve the reflection and absorption of light waves of specific frequencies, thereby obtaining better light wave control effect.

[0031] Furthermore, the anti-resonant layer is a single-layer or multi-layer structure, such as... Figure 2As shown, the anti-resonant layer 4 includes a first anti-resonant layer unit 41 and a second anti-resonant layer unit 42. Therefore, the two anti-resonant layer units can achieve reflection and interference of light waves, reducing the leakage of light energy to the outer cladding. Furthermore, the anti-resonant units in different layers can be optimized for different wavelengths of light. By adjusting the parameters of each anti-resonant layer unit (such as thickness and refractive index), low-loss transmission of the optical fiber can be achieved over a wide wavelength range. Therefore, the thickness of the anti-resonant layer and the thickness of the nested structure unit are configured to satisfy the anti-resonant reflection and light guiding conditions at the target wavelength.

[0032] Furthermore, the material of each anti-resonance layer and each anti-resonance unit is silicon dioxide; and the thickness of the anti-resonance layer satisfies the following formula: (1) Where m is the order of the anti-resonance. m = 0, 1, 2, ... represents different orders; the higher the order, the greater the thickness. Usually, a lower order (such as m = 0 or 1) is chosen to design the thickness. For transmission wavelength, It is the refractive index of silicon dioxide. It is the refractive index of the air in the fiber core. In specific implementations, it can be set... 1550 nm It is 1.45. It can be approximated as 1. Calculations show that when m = 1, t = 1162.5 nm, yielding the theoretical value of the silicon dioxide anti-resonant layer thickness t.

[0033] The thickness can be designed for different wavelengths according to formula (1), and the thickness of the anti-resonant ring that meets the same wavelength can be set so that the wavelength has low propagation loss in the fiber core.

[0034] In this embodiment, all anti-resonant loops are considered to have a first-order resonant thickness. The thickness corresponding to a wavelength of 1550 nm is set to 1162.5 nm.

[0035] The support structure disclosed in this application includes one or more support units, each of which is a straight structure, a curved structure, or a hybrid structure composed of straight lines and curves.

[0036] In specific implementation, the support unit is one or more glass rods; when the support unit is linear and contains multiple glass rods, the glass rods are arranged side by side; when the support unit is curved, the curvature of the curved glass rods corresponding to each anti-resonance unit is kept consistent, and the curvature of the curved glass rods corresponding to adjacent anti-resonance units is opposite. Figure 3As shown, the support structure consists of two straight glass rods arranged side by side. Because multiple glass rods are used side-by-side to support the nested structural units, a more stable support effect can be achieved. Combined with... Figure 4 As shown, the support unit can also be configured as a curved structure. A curved support structure offers greater design and fabrication diversity, facilitating optimal selection of the fabrication process. It can be composed of one or more curved glass rods. For example, the curved glass rod can have a symmetrical arch structure, an S-shaped curve, a wave-shaped structure, or a spiral structure.

[0037] like Figure 5 As shown, the anti-resonance unit contains one nested structure unit, and each nested structure unit is connected to two support units, which are in a straight line shape. One end of the two support units is connected and they are inclined at a certain angle to each other. The connected end of the two support units is attached to the nested structure unit 21, and the other end of the two support units is connected to the inner wall of the outer cladding layer 1.

[0038] like Figure 6 As shown, the anti-resonant layer can also be connected to the support structure 22. That is, both ends of the first anti-resonant layer unit 41 and the second anti-resonant layer unit 42 are connected to the support structure, thereby fixing the position of the anti-resonant layer using the support structure. Since optical fibers may be subjected to mechanical stresses such as tension, compression, or bending during application, and the support structure may disperse and bear some of the stress, the support structure provides support and protection for the anti-resonant layer, which can better protect the anti-resonant layer and improve the reliability of optical fibers in complex environments.

[0039] The hollow-core anti-resonant fiber structure disclosed herein can reduce transmission loss and suppress light leakage, thereby achieving low transmission loss or even ultra-low transmission loss, for example, ultra-low transmission loss of less than 0.01 dB / km can be achieved.

[0040] The following detailed description of the low-loss hollow anti-resonant optical fiber provided by the present invention will be based on specific application examples.

[0041] First Embodiment like Figure 1 The diagram shown is a schematic representation of the hollow anti-resonant optical fiber according to the first embodiment of this application. Figure 1As shown, in the first embodiment, the hollow anti-resonant optical fiber includes: an outer cladding layer 1 and a plurality of anti-resonant units 20 disposed within the outer cladding layer 1. Each anti-resonant unit 20 includes a nested structural unit constructed from two nested circular glass tubes of different radii and a support structure. Each anti-resonant unit is connected to the inner wall of the outer cladding layer through the support structure. The two nested circular glass tubes are connected to each other, with the smaller-radius nested circular glass tube located inside the larger-radius nested circular glass tube. The connection point between the two nested circular glass tubes is located at the connection point between the nested structural unit and the support structure, that is, the two connection points coincide, thus forming a "lollipop" shaped structure with one end circular and the other end straight.

[0042] like Figure 1 As shown, the outer cladding layer has six anti-resonant units. Two adjacent anti-resonant units 2 are spaced apart to form a gap, which can be approximately 20 mm. The distance is such that an arc-shaped anti-resonance layer 4 is provided at the junction of the gap and the inner wall of the cladding structure 1. The anti-resonance layer 4 has a uniform wall thickness.

[0043] The anti-resonance unit 2 consists of a nested structural unit 21 and a support structure 22 supporting the nested structural unit 21; the nested structural unit 21 includes two nested glass tubes with different radii. The support structure 22 connects the nested structural unit to the inner wall of the cladding structure 1. like Figure 1 The first embodiment shown does not include the arc-shaped anti-resonant layer 4, and six anti-resonant units are arranged at equal intervals along the inner wall of the cladding. The core diameter can be 40 mm. For any one of the six anti-resonant units, the diameter of the inner nested circular glass tube can be 33. The diameter of the nested circular glass tubes located in the inner layer can be 26. The length of the supporting structure can be 10. The width is equal to the thickness of the anti-resonant ring. Within the wavelength range of 1250nm to 1700nm, Figure 1 The optical fiber shown can achieve a loss of 0.0036 dB / km; the loss curve can be referenced. Figure 7 .

[0044] Second Embodiment like Figure 2 The diagram shown is a schematic representation of the hollow anti-resonant optical fiber according to the second embodiment of this application. The difference between this embodiment and the first embodiment is that an anti-resonant layer is provided. The outer cladding layer contains six "lollipop"-shaped anti-resonant units 2 arranged at equal angular intervals around its inner wall along the central axis of the outer cladding layer 1; and a fiber core region 3 formed by the six "lollipop"-shaped anti-resonant units 2.

[0045] In one implementation, the fiber core diameter is set to 40. Of the six "lollipop"-shaped enclosed cavities, the outermost nested circular glass tube has a diameter of 28.3 mm. The diameter of the nested circular glass tubes located in the inner layer is 24. The length of the supporting structure is 10. The width is equal to the thickness of the anti-resonant ring. It should be noted that for parameters of hollow-core antiresonant optical fibers, one can conceive that parameters such as the wall thickness of the inner cladding and the spacing between antiresonant units must satisfy the antiresonance condition. Only when these parameters are within the range required for antiresonance reflection can hollow-core antiresonant optical fibers, as a type of optical fiber, coherently and destructively suppress light leakage and thus reduce fiber loss through the antiresonance principle and the structural design of the fiber.

[0046] The hollow-core antiresonant optical fiber with a "lollipop"-shaped antiresonant unit structure disclosed in this embodiment can significantly reduce transmission loss and suppress light leakage. See further details. Figure 8 , it is Figure 2 The performance parameters of the structured optical fiber are as follows: at a wavelength of 1550 nm, the fiber loss is as low as 0.01 dB / km.

[0047] Third Embodiment like Figure 3 As shown, the main difference between the third embodiment and the first embodiment is that the support structure adopts a double support rod form (instead of a single rod), that is, two glass rods are used as the support structure, while the other structures are the same. Figure 9 As shown, it can achieve a loss of 0.0817 dB / km at a wavelength of 1500 nm.

[0048] Fourth embodiment like Figure 4 As shown, the hollow anti-resonant optical fiber in the fourth embodiment differs from that in the first embodiment in that the supporting structure is changed from a straight glass rod to a curved glass rod.

[0049] Fifth embodiment like Figure 5 As shown, the hollow anti-resonant optical fiber disclosed in this fifth embodiment differs from that in the fourth embodiment only in that the support structure consists of two straight glass rods at a certain angle.

[0050] Sixth Embodiment like Figure 6 As shown, the hollow anti-resonant optical fiber disclosed in this sixth embodiment differs from that in the second embodiment only in that the anti-resonant layer is not directly connected to the inner wall of the outer cladding, but is connected to the support structure.

[0051] This embodiment provides a low-loss hollow-core anti-resonant optical fiber, comprising: an outer cladding, a plurality of anti-resonant units disposed within the outer cladding, and a core region enclosed by each anti-resonant unit; each anti-resonant unit is arranged circumferentially around the central axis of the outer cladding; each anti-resonant unit includes a nested structural unit and a support structure for supporting the nested structural unit, one end of each support structure being connected to the nested structural unit, and the other end being connected to the inner wall of the outer cladding. This invention, by designing the layout of the anti-resonant units within the air-core unit, achieves low-loss and low-power transmission of the target beam in the core region, thereby improving the transmission capability of the hollow-core optical fiber.

[0052] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0053] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A low-loss hollow-core antiresonant optical fiber, characterized in that, include: The outer cladding layer and the multiple anti-resonant units disposed within the outer cladding layer and the fiber core region enclosed by each of the anti-resonant units; Each anti-resonant unit is arranged circumferentially around the central axis of the outer cladding layer; Each of the anti-resonance units includes a nested structural unit and a support structure for providing support for the nested structural unit. One end of each support structure is connected to the nested structural unit, and the other end is connected to the inner wall of the outer cladding.

2. The low-loss hollow-core antiresonant optical fiber according to claim 1, characterized in that, Each anti-resonant unit is arranged at equal or non-equal angle intervals along the inner wall of the outer cladding, and there is a preset gap between two adjacent anti-resonant units.

3. The low-loss hollow-core antiresonant optical fiber according to claim 1, characterized in that, The support structure includes one or more support units, each of which is a straight structure, a curved structure, or a hybrid structure composed of straight lines and curves.

4. The low-loss hollow-core antiresonant optical fiber according to claim 3, characterized in that, The support unit is one or more glass rods; when the support unit is linear and contains multiple glass rods, the glass rods are arranged side by side; when the support unit is curved, the curved glass rods corresponding to each anti-resonance unit have the same bending direction, or the curved glass rods corresponding to each adjacent anti-resonance unit have opposite bending directions.

5. The low-loss hollow-core antiresonant optical fiber according to claim 3, characterized in that, The anti-resonance unit contains one nested structural unit, and each nested structural unit is connected to two supporting units, which are in a straight line shape. The two supporting units are inclined at a certain angle to each other, and one end of the two supporting units is attached to the nested structural unit, while the other end is connected to the inner wall of the outer cladding layer.

6. The low-loss hollow-core antiresonant optical fiber according to claim 2 or 3, characterized in that, The nested structural unit includes one or more nested circular glass tubes with different radii, and the radii of each nested circular glass tube increase or decrease sequentially, with the centers of the tubes on the same straight line, forming an eccentric nested structure. Each nested circular glass tube is connected to the corresponding support structure of its nested structural unit.

7. The low-loss hollow-core antiresonant optical fiber according to claim 1, characterized in that, An anti-resonance layer is provided between each of the anti-resonance units; the anti-resonance layer is connected to the inner wall of the outer cladding layer, or the anti-resonance layer is connected to the support structure.

8. The low-loss hollow-core antiresonant optical fiber according to claim 7, characterized in that, The anti-resonance layer can be arc-shaped, circular, fan-shaped, elliptical, or polygonal.

9. The low-loss hollow-core antiresonant optical fiber according to claim 7, characterized in that, The anti-resonance layer is a single-layer or multi-layer structure, and the thickness of the anti-resonance layer and the thickness of the nested structural unit are configured to satisfy the anti-resonance reflection light guiding condition at the target wavelength.

10. The low-loss hollow-core antiresonant optical fiber according to claim 7, characterized in that, The material of each anti-resonance layer and each anti-resonance unit is silicon dioxide; and the thickness of the anti-resonance layer satisfies the following formula: ； Where m is a natural number. For transmission wavelength, It is the refractive index of silicon dioxide. It is the refractive index of the air in the fiber core.

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