Frog-shaped hollow-core anti-resonance optical fiber

Abstract

The invention provides a frog-shaped hollow-core anti-resonance optical fiber. The optical fiber comprises a cladding made of quartz glass, and frog-shaped air holes formed by periodically arranging a plurality of same concave structures are formed in the cladding. Each concave structure is formed by intersecting two concave semi-arc-shaped edges at one end point, and the adjacent concave structures are smoothly connected through a section of convex large semi-arc-shaped wall. A first anti-resonance layer and a second anti-resonance layer are formed on the inner wall of the frog-shaped air hole and used for limiting light waves in an air fiber core defined by the air hole structure for transmission through the anti-resonance reflection effect. Through the unique concave structure design, the invention aims to optimize the light wave limiting capability, so that the optical fiber realizes low-loss transmission at the infrared band of 1.5-2.0 microns, and is suitable for the transmission of high-peak power laser pulses.

Description

Technical Field

[0001] This invention relates to the field of optical fiber technology, and more specifically to a frog-shaped hollow core anti-resonant optical fiber. Background Technology

[0002] Hollow-core antiresonant fiber, as a novel type of microstructured fiber, utilizes photonic bandgap or antiresonance effect to confine light waves within an air core for transmission, fundamentally avoiding the nonlinear effects, dispersion, and loss bottlenecks inherent in traditional silica fiber caused by the material itself. Since light primarily propagates through air, it exhibits enormous application potential in high-peak-power laser transmission, low-latency communication, and gas sensing. Among these, hollow-core fiber based on the antiresonance effect has become a research hotspot due to its theoretically wider transmission bandwidth and lower loss. Its performance hinges on the design of the cladding air hole structure, effectively confining the light field by controlling the antiresonant reflection of light at the air-glass interface.

[0003] However, existing hollow-core antiresonant fibers, especially those using single-structure (e.g., circular or simple arc-shaped) air holes, face significant performance limitations. These traditional single-structure air holes have limited mode constraint capabilities, making it difficult to simultaneously achieve both increased antiresonant bandwidth and reduced transmission loss. Specifically: firstly, the transmission bandwidth is typically narrow, limiting its application in wide-spectrum scenarios such as wavelength division multiplexing; secondly, loss performance fluctuates significantly with wavelength, making it difficult to achieve stable and widespread low-loss transmission in the target wavelength band (e.g., 1.5μm-2.0μm). This deficiency stems from the difficulty in flexibly and precisely controlling the antiresonant conditions with a single geometry, making it difficult to meet the stringent requirements of low-loss and wide-bandwidth characteristics for applications such as high peak power laser transmission. Summary of the Invention

[0004] This invention provides a frog-shaped hollow-core anti-resonant optical fiber to solve the problem in the prior art that traditional single-structure air holes cannot simultaneously achieve anti-resonant bandwidth expansion and transmission loss suppression, resulting in narrow optical fiber transmission bandwidth and large wavelength fluctuations in loss.

[0005] To achieve the above objectives, embodiments of the present invention provide a frog-shaped hollow anti-resonant optical fiber, comprising: a cladding layer, including an outer cladding region and an inner cladding region, the cladding layer being made of quartz glass; a frog-shaped air hole, located inside the cladding layer, composed of a plurality of identical concave structures arranged periodically, each concave structure being formed by two concave semi-circular arc edges converging at one end, adjacent concave structures being smoothly connected by a section of convex large semi-circular arc wall, and surrounded by the cladding material; a first anti-resonant layer and a second anti-resonant layer, used to cause anti-resonant reflection of light waves on the inner wall of the frog-shaped air hole; and an air core, surrounded by the frog-shaped air hole, in which light waves are confined for transmission after being reflected by the first anti-resonant layer and the second anti-resonant layer.

[0006] Furthermore, the multiple frog-shaped air holes are distributed in a fivefold rotational symmetry around the central axis of the optical fiber.

[0007] Furthermore, the geometric shapes of both the concave semicircular arc edge and the convex semicircular arc wall are circular arcs.

[0008] Furthermore, the radius of the convex semicircular wall of the frog-shaped air hole is twice the radius of the concave semicircular side.

[0009] Furthermore, the concavity coefficient of the frog-shaped air hole is 0.3-0.7, and the concavity coefficient is the ratio of the chord length of the concave semicircular arc side to the chord length of the convex semicircular arc wall; the frog-shaped air hole is nested with a circular air hole, and the ratio of the diameter of the circular air hole to the radius of the concave semicircular arc side is 0.2-0.5.

[0010] Furthermore, the cladding layer is also provided with a plurality of auxiliary air holes, the auxiliary air holes having a circular cross-section and being arranged around the frog-shaped air holes.

[0011] Furthermore, the diameter of the auxiliary air hole is 0.3-0.8 times the radius of the outwardly convex semicircular arc wall of the frog-shaped air hole, and the distance between the center of the auxiliary air hole and the center of the geometric center of the frog-shaped air hole is 1.0-1.5 times the sum of their radii.

[0012] Furthermore, the multiple auxiliary air holes are arranged in a uniform ring around the frog-shaped air hole.

[0013] Furthermore, the multiple concave structures are arranged at equal angles with the central axis of the optical fiber as the axis of symmetry.

[0014] Furthermore, the optical fiber has one or more low-loss transmission windows in the 1.5μm-2.0μm infrared band and is suitable for the transmission of high peak power laser pulses.

[0015] The frog-shaped hollow-core anti-resonant optical fiber provided by this invention uses frog-shaped air holes composed of multiple identical concave structures arranged periodically as the core anti-resonant unit, and distributes them in a five-fold rotational symmetry around the central axis of the fiber, which effectively enhances the anti-resonant reflection effect of light waves in the air core. By precisely defining the radius ratio of the convex semi-circular wall to the concave semi-circular side, the concavity coefficient, and the size ratio of the nested circular air holes, the anti-resonance conditions are significantly optimized, thereby realizing one or more low-loss transmission windows in the 1.5μm-2.0μm infrared band, while improving the transmission capability of the optical fiber for high peak power laser pulses, and solving the problems of narrow bandwidth and large loss fluctuation with wavelength in traditional single-structure air hole optical fibers. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings:

[0017] Figure 1 This is a cross-sectional view of the optical fiber in Embodiment 1 of the present invention; Figure 2 This is a cross-sectional view of the optical fiber in Embodiment 2 of the present invention; Figure 3 This is a cross-sectional view of the optical fiber in Embodiment 3 of the present invention.

[0018] Among them, 1. Outer cladding region; 2. Inner cladding region; 3. Second anti-resonance layer; 4. First anti-resonance layer; 5. Air core. Detailed Implementation

[0019] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of the present invention.

[0020] It should be noted that the acquisition, transmission, storage, use, and processing of data in the technical solution of this application all comply with the relevant provisions of national laws and regulations. In the embodiments of this application, certain existing industry solutions such as software, components, and models may be mentioned. These should be considered exemplary, intended only to illustrate the feasibility of implementing the technical solution of this application, and do not imply that the applicant has already used or necessarily used such solutions.

[0021] With the widespread application of high peak power laser technology in industrial processing, medical surgery, and scientific research, increasingly stringent requirements have been placed on the power carrying capacity and low-loss characteristics of transmission optical fibers. While existing hollow-core antiresonant fibers achieve light wave transmission in air through circular or single-arc air-hole structures, their antiresonant unit design still has inherent defects. Particularly noteworthy is the limited mode constraint capability of traditional single-structure air-hole fibers, making it difficult to simultaneously achieve both the expansion of antiresonant bandwidth and the suppression of transmission loss. This results in narrow fiber transmission bandwidth and large wavelength-dependent loss fluctuations, hindering stable and widespread low-loss transmission in key infrared bands such as 1.5μm–2.0μm, severely limiting their performance in high-end applications such as high peak power laser pulse transmission.

[0022] To address this core technological bottleneck, this invention discloses a frog-shaped hollow-core anti-resonant optical fiber. This fiber achieves fundamental optimization of the anti-resonance effect at the optical level through its innovative air-hole structure design. This invention employs a frog-shaped air-hole, composed of multiple periodically arranged identical concave structures, as the core anti-resonance unit. The concave semi-circular edges and convex large semi-circular walls are precisely combined to form a multi-layered, synergistic anti-resonance interface. This design significantly enhances the reflection efficiency of light waves at the air-quartz interface, effectively broadens the anti-resonance bandwidth, and significantly suppresses transmission loss.

[0023] The following is combined with Figures 1-3 This invention is described in detail.

[0024] Example 1 like Figure 1 As shown, this embodiment of the invention provides a frog-shaped hollow anti-resonant optical fiber, comprising: a cladding layer, including an outer cladding region and an inner cladding region, the cladding layer being made of quartz glass; a frog-shaped air hole, located inside the cladding layer, composed of multiple identical concave structures arranged periodically, each concave structure being formed by two concave semi-circular arc edges converging at one end, adjacent concave structures being smoothly connected by a convex large semi-circular arc wall, and surrounded by the cladding material; a first anti-resonant layer and a second anti-resonant layer, used to cause anti-resonant reflection of light waves on the inner wall of the frog-shaped air hole; and an air core, surrounded by the frog-shaped air hole, in which light waves are confined for transmission after being reflected by the first and second anti-resonant layers.

[0025] Specifically, the frog-shaped hollow anti-resonant optical fiber provided in this embodiment of the invention has a core structure composed of multiple identical concave structures arranged periodically to form anti-resonant units. Each concave structure is formed by two concave semi-circular arc edges converging at one end. Adjacent concave structures are smoothly connected by convex large semi-circular arc walls, forming a closed ring structure that surrounds and defines the central air core. The curvature radii of the concave semi-circular arc edges and the convex large semi-circular arc walls are optimized to ensure efficient anti-resonant reflection of light waves at the air-quartz interface. The first and second anti-resonant layers correspond to the interfaces of the concave edges and convex walls of the concave structures, respectively, and work together to suppress optical field leakage through multiple anti-resonant effects. The cladding is made of pure quartz glass, with the inner cladding region directly surrounding the frog-shaped air hole, while the outer cladding region provides mechanical support and boundary constraints. When light waves propagate in the air core, they are mainly confined to the low-refractive-index region surrounded by multiple concave structures, achieving low-loss transmission through the anti-resonant reflection mechanism.

[0026] The frog-shaped hollow anti-resonant fiber provided in this invention has a unique air hole design formed by a periodic arrangement of multiple concave structures, and utilizes the first and second anti-resonant layers formed by its inner wall to effectively enhance the anti-resonant reflection effect of light waves at the air-quartz interface. This efficiently confines the light field within the air core for transmission, ultimately achieving a low-loss transmission window in the 1.5μm-2.0μm infrared band and meeting the transmission requirements of high peak power laser pulses.

[0027] Preferably, the plurality of the frog-shaped air holes are distributed in a fivefold rotational symmetry around the central axis of the optical fiber.

[0028] Specifically, this geometric arrangement is a key topological feature for achieving superior optical performance. Specifically, with the fiber's central axis as the rotation axis, the entire cladding air hole structure completely overlaps geometrically every 72 degrees. This high degree of rotational symmetry ensures the equivalence of the fiber cross-section in all directions, effectively suppressing the excitation and transmission of higher-order modes and promoting the stable existence of the fundamental mode. Simultaneously, the symmetrical structure helps to counteract birefringence effects caused by minor process deviations or external stresses, thus ensuring the polarization stability of the transmitted light field and providing the necessary structural foundation for forming a flat, low-loss transmission window in the target infrared band.

[0029] Preferably, the geometric shapes of the concave semicircular side and the convex semicircular wall are both circular arcs.

[0030] In a further preferred embodiment, the radius of the convex semicircular wall of the frog-shaped air hole is twice the radius of the concave semicircular side.

[0031] More preferably, the concavity coefficient of the frog-shaped air hole is 0.3-0.7, and the concavity coefficient is the ratio of the chord length of the concave semicircular arc side to the chord length of the convex semicircular arc wall; the frog-shaped air hole is nested with a circular air hole, and the ratio of the diameter of the circular air hole to the radius of the concave semicircular arc side is 0.2-0.5.

[0032] Specifically, the concave semicircular arc edge constituting each concave structure and the convex large semicircular arc wall connecting adjacent structures are both standard arc shapes. This ensures the consistency and predictability of the wavefront phase when light waves are reflected at the interface, which is the geometric basis for achieving efficient anti-resonance effects. Under this premise, the radius R of the convex large semicircular arc wall is designed to be twice the radius r of the concave semicircular arc edge, that is, satisfying the key proportional relationship R=2r. This specific ratio was determined after simulation optimization, which enables the anti-resonance phase conditions excited by light waves at the inner and outer arc interfaces to produce a beneficial synergistic effect, thereby more effectively widening the anti-resonance bandwidth. Furthermore, to finely control the optical performance, the concavity coefficient, a key parameter, is introduced, which is defined as the chord length L of the concave semicircular arc edge. inThe chord length L of the outwardly convex semi-circular arc wall out The ratio of the diameter d to the radius r of the concave semicircular arc is set between 0.3 and 0.7. This coefficient directly affects the opening depth and shape of the concave structure, thus determining the depth and width of the anti-resonance peak. Simultaneously, to further enhance the optical field confinement capability and perturb higher-order modes that are detrimental to transmission, a circular air hole can be nested inside the frog-shaped air hole. By controlling the ratio d / r of its diameter d to the radius r of the concave semicircular arc within the range of 0.2 to 0.5, the distribution of the mode field within the fiber core can be finely adjusted, ultimately contributing to the excellent low-loss and wide-bandwidth characteristics of the optical fiber in the target wavelength band.

[0033] In a preferred embodiment of the present invention, the geometry of the anti-resonance unit is defined as a standard circular arc, and its key size ratios are precisely set, such as the radius ratio of the outer convex wall to the inner concave side being 2:1. The concavity coefficient and the size of the nested circular hole are also optimized. These features work together to finely control the anti-resonance conditions of the light wave, thereby effectively widening the transmission bandwidth of the optical fiber and significantly reducing its loss.

[0034] Preferably, the cladding layer is further provided with a plurality of auxiliary air holes, the auxiliary air holes having a circular cross-section and being arranged around the frog-shaped air holes.

[0035] More preferably, the diameter of the auxiliary air hole is 0.3-0.8 times the radius of the outwardly convex semicircular arc wall of the frog-shaped air hole, and the distance between the center of the auxiliary air hole and the center of the geometric center of the frog-shaped air hole is 1.0-1.5 times the sum of their radii.

[0036] More preferably, the plurality of auxiliary air holes are arranged in a ring-shaped uniform arrangement with the frog-shaped air hole as the center.

[0037] Specifically, multiple auxiliary air holes with circular cross-sections are arranged around the core frog-shaped air hole to form a composite cladding structure. These auxiliary air holes further optimize the waveguide characteristics of the optical fiber: firstly, they can effectively disturb and leak higher-order modes, suppressing their transmission and thus improving the purity and stability of the fundamental mode; secondly, they can adjust the equivalent refractive index distribution of the cladding, enhancing the confinement of the fundamental mode optical field in the fiber core, helping to reduce confinement loss, especially reducing energy leakage when the fiber is bent. The diameter D of the auxiliary air holes... assist The radius R of the protruding semicircular arc wall of the main air hole satisfies D assist =(0.3~0.8)R, and the distance L between its center and the geometric center of the main air hole. distance Satisfy L distance =(1.0~1.5)×(R assist +R), where R assistThe radius of the auxiliary air holes represents the radius of the auxiliary air holes. This design ensures that the auxiliary air holes can effectively influence the mode field without excessively interfering with the function of the main anti-resonant structure. In addition, multiple auxiliary air holes are arranged in a ring around the main air hole in a uniform manner. This symmetrical layout helps to maintain the macroscopic optical uniformity of the fiber and avoids introducing unnecessary anisotropy or polarization-dependent losses.

[0038] In a preferred embodiment of the present invention, circular auxiliary air holes of a specific size and arrangement are set around the main anti-resonant structure, which effectively enhances the optical fiber's ability to confine the optical field and suppresses the transmission of higher-order modes, thereby synergistically reducing the overall transmission loss and bending loss of the optical fiber.

[0039] Preferably, the plurality of the concave structures are arranged at equal angles with the central axis of the optical fiber as the axis of symmetry.

[0040] Specifically, for example, there are five concave structures, with the angle between the centerlines of adjacent concave structures being 72 degrees. This equiangular arrangement ensures the strict periodicity of the anti-resonant units in the circumferential direction, making the waveguide boundary conditions and anti-resonance effects experienced by the light wave in any radial direction completely consistent when propagating in the air fiber core. This high degree of uniformity is crucial for maintaining the stability of the transmission mode, effectively avoiding mode coupling or polarization mode dispersion caused by structural asymmetry, thereby ensuring that the optical fiber obtains stable and low-loss single-mode transmission characteristics in the target operating wavelength range (1.5μm-2.0μm).

[0041] Preferably, the optical fiber has one or more low-loss transmission windows in the 1.5μm-2.0μm infrared band and is suitable for the transmission of high peak power laser pulses.

[0042] Specifically, the hollow-core antiresonant optical fiber provided by this invention has one or more low-loss transmission windows in the infrared band of 1.5μm–2.0μm. By efficiently confining light waves within the air core through the antiresonance effect, transmission loss caused by absorption and scattering by the quartz material is significantly reduced, while bending loss is effectively suppressed. Furthermore, since the light energy is mainly distributed in the air, the nonlinear effects and damage threshold limitations of the quartz material are avoided, making this optical fiber particularly suitable for the transmission of high peak power laser pulses, capable of carrying higher power densities while maintaining good beam quality and low signal distortion.

[0043] As a specific implementation scheme, the key geometric parameters of this embodiment can be set as follows: the radius r of the concave semicircular arc side is set to 8μm, and according to the preferred ratio, the radius R of the convex large semicircular arc wall is 16μm. At this time, the calculated concavity coefficient is approximately 0.45. The diameter of the distribution circle where the geometric centers of the multiple concave structures are located is approximately 50μm. Through finite element method simulation, the confined loss simulation value of the optical fiber under this structural parameter at a communication wavelength of 1550nm is less than 0.08dB / km, exhibiting excellent low-loss characteristics.

[0044] Example 2 like Figure 2 As shown, the frog-shaped hollow anti-resonant optical fiber provided in this embodiment has the same basic structure as that in Embodiment 1, namely, it includes a cladding made of quartz glass and frog-shaped air holes formed by a periodic arrangement of multiple identical concave structures. These multiple air holes are distributed in a five-fold rotational symmetry around the central axis of the optical fiber. Each concave structure is formed by the intersection of two concave semi-circular arc edges at a point, and adjacent concave structures are smoothly connected by a convex large semi-circular arc wall. Both the concave semi-circular arc edges and the convex large semi-circular arc wall are standard arcs.

[0045] In Example 1, each frog-shaped air hole contains one nested circular air hole. In Example 2, each frog-shaped air hole contains two nested circular air holes. These two circular air holes can be arranged along the axis of symmetry of the concave structure or in a specific direction. The ratio d / r of the diameter d of the circular air hole to the radius r of the concave semicircular arc side is kept within an optimized range of 0.2 to 0.5; for example, d / r = 0.35 can be selected.

[0046] In this embodiment, the basic dimensions of Embodiment 1 are inherited, such as r=8μm and R=16μm. The diameter d of both nested circular air holes is set to 3.2μm, i.e., d / r=0.4, and the center distance between the two holes is 6μm. Simulation results show that this design further reduces the confinement loss at a wavelength of 1550nm to approximately 0.05dB / km, and the loss is below 0.1dB / km in the 1500-1600nm band, demonstrating a wider transmission bandwidth.

[0047] By introducing two nested circular air holes in each main anti-resonant unit, the mode field distribution and equivalent refractive index within the anti-resonant unit can be further finely controlled, which may optimize the dispersion characteristics, cutoff wavelength, or loss in a specific band of the optical fiber, providing another optional design scheme for different application requirements.

[0048] Example 3 like Figure 3 As shown, the frog-shaped hollow anti-resonant optical fiber provided in this embodiment has the same basic optical fiber structure as that in Embodiment 1.

[0049] Specifically, in this embodiment, each frog-shaped air hole contains three nested circular air holes. These three circular air holes can be arranged in a specific array within the concave structure, such as a triangle or a line. The ratio d / r of the diameter d of the circular air hole to the radius r of the concave semicircular arc side is kept within an optimized range of 0.2 to 0.5; for example, d / r = 0.3 can be selected.

[0050] In this embodiment, the basic dimensions of Embodiment 1 are also inherited. The diameter d of the three nested circular air holes is set to 2.4 μm, i.e., d / r = 0.3, and they are arranged in a specific array. This structure has unique advantages in dispersion planarization for specific wavelengths (such as 2.0 μm).

[0051] By introducing three nested circular air holes in each main anti-resonant unit, the equivalent refractive index distribution of the anti-resonant unit can be modulated to a greater extent. This allows for more flexible control of the dispersion characteristics of the optical fiber, or the attainment of more extreme loss performance in a specific wavelength band. This provides another design option with different optimization focuses for the transmission of high peak power laser pulses in the 1.5μm–2.0μm infrared band.

[0052] In summary, the frog-shaped hollow anti-resonant optical fiber provided by this invention employs a unique frog-shaped air hole formed by a periodic arrangement of multiple identical concave structures as the core anti-resonant unit, distributing them in a five-fold rotational symmetry around the fiber's central axis. Simultaneously, it precisely defines the radius ratio of the convex semi-circular wall to the concave semi-circular side as 2:1, the concavity coefficient as 0.3–0.7, and nests circular air holes within the main air hole with a diameter-to-concave side radius ratio of 0.2–0.5. Optionally, it also provides circular auxiliary air holes of specific size and arrangement around the main structure, effectively enhancing the anti-resonance of light waves in the air. The anti-resonance reflection effect of the quartz interface optimizes the anti-resonance conditions and mode field distribution, thereby realizing one or more low-loss, wide-bandwidth transmission windows in the infrared band of 1.5μm–2.0μm. This significantly reduces transmission loss and bending loss, and effectively suppresses higher-order modes, ultimately making the fiber particularly suitable for the transmission of high peak power laser pulses. It solves the problems of narrow bandwidth and large wavelength fluctuations in traditional single-structure air-hole fibers.

[0053] The above description is merely a preferred embodiment of the technical solution of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A frog-shaped hollow-core anti-resonant optical fiber, characterized in that, include: The cladding includes an outer cladding region (1) and an inner cladding region (2), the cladding being made of quartz glass; The frog-shaped air hole is located inside the cladding and is composed of multiple identical concave structures arranged periodically. Each concave structure is formed by two concave semi-circular arc edges converging at one end. Adjacent concave structures are smoothly connected by a section of convex large semi-circular arc wall and are surrounded by cladding material. The first anti-resonance layer (4) and the second anti-resonance layer (3) are used to make light waves undergo anti-resonance reflection on the inner wall of the frog-shaped air hole; The air core (5) is surrounded by the frog-shaped air holes, and the light waves are confined and transmitted within it after being reflected by the first anti-resonant layer (4) and the second anti-resonant layer (3).

2. The frog-shaped hollow anti-resonant optical fiber according to claim 1, characterized in that, The multiple frog-shaped air holes are distributed in a multi-rotational symmetry around the central axis of the optical fiber.

3. The frog-shaped hollow anti-resonant optical fiber according to claim 1, characterized in that, Both the concave semicircular side and the convex semicircular wall have circular arc shapes.

4. The frog-shaped hollow anti-resonant optical fiber according to claim 1, characterized in that, The radius of the convex semicircular wall of the frog-shaped air hole is twice the radius of the concave semicircular side.

5. The frog-shaped hollow anti-resonant optical fiber according to claim 4, characterized in that, The concavity coefficient of the frog-shaped air hole is 0.3-0.7, and the concavity coefficient is the ratio of the chord length of the concave semicircular arc side to the chord length of the convex semicircular arc wall; the frog-shaped air hole is nested with a circular air hole, and the ratio of the diameter of the circular air hole to the radius of the concave semicircular arc side is 0.2-0.

5.

6. The frog-shaped hollow anti-resonant optical fiber according to claim 1, characterized in that, The cladding also includes multiple auxiliary air holes, each with a circular cross-section, arranged around the frog-shaped air hole.

7. The frog-shaped hollow anti-resonant optical fiber according to claim 6, characterized in that, The diameter of the auxiliary air hole is 0.3-0.8 times the radius of the outwardly convex semicircular arc wall of the frog-shaped air hole, and the distance between the center of the auxiliary air hole and the center of the geometric center of the frog-shaped air hole is 1.0-1.5 times the sum of their radii.

8. The frog-shaped hollow anti-resonant optical fiber according to claim 6, characterized in that, The multiple auxiliary air holes are arranged in a uniform ring around the frog-shaped air hole.

9. The frog-shaped hollow anti-resonant optical fiber according to claim 1, characterized in that, Multiple concave structures are arranged at equal angles with the central axis of the optical fiber as the axis of symmetry.

10. The frog-shaped hollow anti-resonant optical fiber according to claim 1, characterized in that, The optical fiber has one or more low-loss transmission windows in the 1.5μm-2.0μm infrared band and is suitable for the transmission of high peak power laser pulses.

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