Enhanced stress-resistant hollow-core anti-resonance optical fiber

Abstract

The invention provides an enhanced stress-resistant hollow-core anti-resonance optical fiber, and the optical fiber comprises a plurality of supporting bodies which are arranged between an outer cladding layer and an inner cladding layer in an annular array. The inner wrapping layer comprises a first hollow glass tube, the fiber core area is wrapped by the first hollow glass tube, and the outer side of the first hollow glass tube is tangent to the supporting body. According to the invention, the plurality of supporting bodies are designed, so that mechanical stress applied by the outside can be effectively dispersed, and structural deformation of the inner cladding due to stress concentration is avoided; meanwhile, the first hollow glass tube is designed, so that low-loss transmission of light waves within a specific wavelength range is realized; in combination with the high-strength outer cladding, the optical fiber structure can still keep stable optical performance and structural integrity in severe environments of bearing external pressure, bending, vibration and the like.

Description

Technical Field

[0001] The invention relates to the technical field of optical fibers, and in particular to an enhanced stress-resistant hollow-core anti-resonance optical fiber. Background Art

[0002] In optical fiber communication and laser transmission, traditional optical fibers are difficult to meet the needs of high-power long-distance transmission due to problems such as material absorption, nonlinear effects, and fiber bending losses. In recent years, hollow core anti-resonant fiber (HC-ARF) has become a hot topic of research because of its ability to significantly reduce the loss and nonlinear effects in optical fiber materials due to the propagation of light in the hollow core.

[0003] The inner cladding of the existing hollow-core antiresonant optical fiber structure usually adopts a nested thin-walled ring structure, and the geometric parameters of the antiresonant layer (such as glass wall thickness, glass tube or the spacing between nested glass tubes) play a decisive role in the transmission mode and loss characteristics of the optical fiber. However, this nested thin-walled ring structure faces many challenges in practical applications: for example, the mode field distribution of the optical fiber may cause transmission performance fluctuations due to structural instability; during the manufacturing process, the nested thin-walled ring structure is also prone to defects and errors, increasing the difficulty and cost of production. In addition, the hollow-core structure in the traditional design has low mechanical strength in complex environments (such as high temperature, high pressure, mechanical vibration, etc.), which makes it difficult to meet the application requirements under harsh conditions. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the prior art and provide an enhanced stress-resistant hollow-core anti-resonant optical fiber, which can solve the problems of low mechanical strength, weak stress resistance, high loss, etc. of optical fiber in the prior art under complex environments.

[0005] In order to achieve the above purpose and other purposes, the present invention is implemented by including the following technical solutions: The present invention proposes an enhanced stress-resistant hollow-core antiresonant optical fiber, including multiple supports arranged in a ring array between an outer cladding and an inner cladding; the inner cladding includes a first hollow glass tube, the first hollow glass tube covers the core region, and the outer side of the first hollow glass tube is tangent to the support body.

[0006] In one embodiment, the support body is tangent to the inner side of the outer cladding layer, and two adjacent support bodies are arranged in contact with each other.

[0007] In one embodiment, the support body is tangent to the inner side of the outer cladding layer, and two adjacent support bodies are spaced apart, and the spacing distance does not exceed the radius of the support body.

[0008] In one embodiment, the support body is a solid cylindrical structure made of silicon dioxide doped with a specific element, wherein the specific element includes calcium, magnesium, aluminum, boron or phosphorus.

[0009] In one embodiment, a line connecting the center of the first hollow glass tube and the support body tangent thereto passes through the center of the core region.

[0010] In one embodiment, the inner cladding further includes a second hollow glass tube, which is disposed between the support body and the first hollow glass tube and is tangent to the support body and not in contact with the first hollow glass tube.

[0011] In one embodiment, the distance between the second hollow glass tube and the first hollow glass tube is equivalent to the wall thickness of the second hollow glass tube.

[0012] In one embodiment, the second hollow glass tube is spaced apart from the first hollow glass tube.

[0013] In one embodiment, the refractive index of the first hollow glass tube is greater than the refractive index of the outer cladding, and the refractive index of the outer cladding is not less than the refractive index of the second hollow glass tube.

[0014] In one embodiment, a line connecting the center of the second hollow glass tube and the support body tangent thereto passes through the center of the core region.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] 1. The present invention can effectively disperse the mechanical stress applied by the outside world through the design of multiple supports, and avoid the structural deformation of the inner cladding due to stress concentration; at the same time, by designing the first hollow glass tube, the light wave can be transmitted with low loss within a specific wavelength range; combined with the high-strength outer cladding, the optical fiber structure of the present invention can still maintain stable optical performance and structural integrity under harsh environments such as external pressure, bending and vibration;

[0017] 2. The close contact arrangement of two adjacent supports of the present invention not only enhances the overall structural stability of the optical fiber and reduces the performance fluctuation caused by manufacturing errors, but also helps to evenly distribute the pressure inside the optical fiber, thereby improving the durability and reliability of the optical fiber. Combined with the design of being tangent to the inner side of the outer cladding, the bending and compression resistance of the optical fiber can be greatly improved;

[0018] 3. The distance between two adjacent supports of the present invention does not exceed the radius of the supports, which allows the optical fiber to have a certain elastic deformation space when subjected to external impact, which helps to absorb the impact energy and protect the optical fiber core from damage;

[0019] 4. The support of the present invention is made of silicon dioxide doped with specific elements, which not only improves the hardness and mechanical strength of the optical fiber, but also enhances the thermal stability of the optical fiber, effectively enhances the tensile and bending resistance of the optical fiber, and significantly improves the durability and environmental stress resistance of the optical fiber;

[0020] 5. Enhanced stress resistance: The support column design inside the outer cladding not only provides additional mechanical support and improves the bending and compression resistance of the optical fiber, but also helps to disperse and absorb externally applied stress, thereby reducing stress concentration points, avoiding premature fatigue and breakage of the optical fiber, and maximizing its mechanical strength;

[0021] 6. The present invention introduces a second hollow glass tube, which can be used as a part of the optical waveguide to improve the light transmission efficiency by reducing the inhomogeneity of the internal medium, and effectively compensates for the length change of the optical fiber caused by temperature change or mechanical stress during use, thereby maintaining the geometric stability and optical performance of the optical fiber;

[0022] 7. The non-contact design of the second hollow glass tube and the first hollow glass tube of the present invention reduces the consistency requirements of the optical fiber structure on the material, which not only makes the manufacturing more flexible, but also reduces the influence of mechanical stress on optical transmission, making the optical fiber more stable.

[0023] 8. The second hollow glass tube of the present invention is spaced apart from the first hollow glass tube, which can achieve optimal mode control and loss reduction;

[0024] 9. The refractive index of the first hollow glass tube of the present invention is greater than that of the second hollow glass tube and the outer cladding, which can form a strong refractive index contrast, thereby ensuring that light can be effectively confined and reflected in the fiber core; the refractive index of the second hollow glass tube can be lower than or close to the refractive index of the outer cladding, which can ensure that the transmission of light between different structures will not cause significant reflection loss;

[0025] 10. The optical fiber structure design of the present invention can maintain excellent optical transmission performance in harsh environments such as high temperature, high pressure, vibration, etc., and is suitable for a variety of application scenarios. This design is particularly suitable for optical fiber sensors that need to work under extreme conditions, such as oil and gas exploration, deep sea detection, aerospace and other fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Shown is a schematic structural diagram of an enhanced stress-resistant hollow-core antiresonant optical fiber of the present invention.

[0027] Figure 2 The effective refractive index curve of Example 1 of the present invention varying with wavelength is shown.

[0028] Figure 3The limiting loss curve of Example 1 of the present invention varying with wavelength is shown.

[0029] Figure 4 The bending loss curve of Example 1 of the present invention as the bending radius changes is shown. DETAILED DESCRIPTION

[0030] See also Figure 1-Figure 4 The following describes the embodiments of the present invention through specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0031] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings in this specification are only used to match the contents disclosed in the specification for the technical personnel in this field to understand and read, and are not used to limit the conditions under which the present invention can be implemented. Therefore, they have no substantive technical significance. Any modification of the structure, change in the proportion relationship or adjustment of the size should still fall within the scope of the technical contents disclosed in the present invention without affecting the effects and purposes that can be achieved by the present invention.

[0032] Unless otherwise defined, the technical or scientific terms used herein shall have the usual meanings as understood by persons having ordinary skills in the field to which the present invention belongs. The terms "first", "second", etc. used in the present invention are used to distinguish different objects, rather than to describe a specific order, quantity or importance. "Include" or "comprising" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. The term "connection" in the present invention includes direct and indirect connections unless otherwise specified.

[0033] like Figure 1 As shown, the present invention provides an enhanced stress-resistant hollow-core antiresonant optical fiber, comprising an outer cladding 1, a support layer, an inner cladding and a core region 5 which are arranged in sequence from the outside to the inside.

[0034] The outer cladding 1 is made of silicon dioxide, has a refractive index of 1.3 to 1.5, an inner diameter of 110 to 130 μm, and a thickness of 50 to 60 μm. The outer cladding 1 covers the support layer 2, the inner cladding (including the first glass tube 4 and the second glass tube 3) and the core region 5, plays a role in protecting the internal structure of the optical fiber and provides the necessary mechanical strength and environmental protection. By wrapping the entire optical fiber structure, the outer cladding 1 prevents the external environment from damaging the internal structure of the optical fiber, such as humidity, mechanical stress, etc., while also providing good mechanical support and protection.

[0035] The support layer includes a plurality of support bodies 2, which are arranged in a circular array between the outer cladding 1 and the inner cladding, and the support bodies 2 are tangent to the inner side of the outer cladding 1 and the outer side of the inner cladding. In some embodiments, two adjacent support bodies 2 can be arranged in close contact to form a support structure with high mechanical strength, which, combined with the design of being tangent to the inner side of the outer cladding 1, can greatly improve the bending and compression resistance of the optical fiber. In other embodiments, two adjacent support bodies 2 can also be arranged at intervals, but the interval distance is small and should not exceed the radius of the support body 2. The number of support bodies 2, whether to set intervals, and the interval distance can be adjusted according to specific application requirements to achieve optimal mechanical properties.

[0036] Specifically, the support body 2 is a solid cylindrical structure with a diameter of 5 to 15 μm, and each support body 2 is made of silicon dioxide doped with specific elements, such as borosilicate glass, phosphate glass or aluminosilicate glass. The specific elements can be selected from one or more of calcium, magnesium, aluminum, boron and phosphorus, among which calcium and magnesium elements can improve mechanical strength; aluminum elements are often used in aluminosilicate glass, which can improve mechanical strength and temperature resistance, and enhance the stability of optical fiber in harsh environments; boron elements are often used in borosilicate glass, which can enhance thermal stability and radiation resistance, and reduce the loss of optical fiber; phosphorus elements are often used in phosphate glass, which can improve the optical properties of optical fiber, increase nonlinear effects, and are suitable for specific sensing applications. The use of these doping materials not only improves the hardness and mechanical strength of the optical fiber, but also enhances the thermal stability of the optical fiber, which can effectively enhance the tensile and bending resistance of the optical fiber, and significantly improve the durability and environmental stress resistance of the optical fiber.

[0037] The inner cladding includes a first hollow glass tube 4 and a second hollow glass tube 3 .

[0038] Among them, the first hollow glass tube 4 is a hollow anti-resonance glass tube filled with air in the center, with a radius r1 of 10 to 17.5 μm, a wall thickness of 0.5 to 1.5 μm, a material of silicon dioxide, and a refractive index greater than the refractive index of the outer cladding 1, which can be 1.5 to 1.6. Its main function is to limit the leakage of light through the anti-resonance effect to ensure that the light can propagate in the core region 5. The wall thickness and spacing of the anti-resonance glass tube are precisely designed to suppress unnecessary light modes by accurately matching the working wavelength of the optical fiber, thereby reducing the loss during optical fiber transmission. Specifically, multiple first hollow glass tubes 4 are arranged in an annular array to cover the core region 5, and their outer sides are tangent to the support body 2. In some embodiments, each first hollow glass tube 4 is tangent to a support body 2, and the line connecting the centers of the two circles passes through the center of the core region 5, so that two adjacent first hollow glass tubes 4 are distributed at a specific distance to form an effective anti-resonance structure.

[0039] The second hollow glass tube 3 is arranged between the support body 2 and the first hollow glass tube 4, the second hollow glass tube 3 does not contact the first hollow glass tube 4, and the second hollow glass tube 3 maintains a distance from the first hollow glass tube 4 that is equivalent to the wall thickness of the second hollow glass tube 3. This contactless design can reduce the loss of light transmitted between different tubes. In the case of no contact, the light wave will form a specific mode field distribution during the propagation process, and the nodes are mainly concentrated near the first hollow glass tube 4, rather than in the gap between the two. This can avoid the interference or diffraction effect caused by the mode distribution of light, thereby reducing unnecessary losses in the optical fiber. When the first hollow glass tube 4 and the second hollow glass tube 3 are not in contact, each tube can independently adjust its anti-resonance condition to minimize the light loss in the core region 5, which helps to ensure that the anti-resonance condition is not affected by adjacent materials, thereby improving the overall performance of the optical fiber. In addition, the contactless design reduces the consistency requirements of the optical fiber structure on the material, which is not only more flexible in manufacturing, but also reduces the impact of mechanical stress on optical transmission, making the optical fiber more stable.

[0040] The number and size of the second hollow glass tubes 3 can be optimized according to design requirements to reduce the mode field diameter and improve the mode distribution of the optical fiber. The distance between the second hollow glass tubes 3 and the wall thickness have an important influence on the mode field characteristics of the optical fiber, so the manufacturing process needs to be accurately controlled to ensure the performance stability of the optical fiber. At the same time, the second hollow glass tubes 3 need to be spaced apart from the first hollow glass tubes 4 to achieve optimal mode control and loss reduction. In some embodiments, each second hollow glass tube 3 is tangent to a support body 2, and the line connecting the centers of the two passes through the center of the core region 5.

[0041] Specifically, the second hollow glass tube 3 is a hollow glass tube filled with air in the center, with a radius r2 of 2.5 to 5 μm, a wall thickness of 0.5 to 1.5 μm, and is made of silicon dioxide. The refractive index is lower than that of the first hollow glass tube 4, and lower than or close to the refractive index of the outer cladding 1, which can be 1.4 to 1.5. The refractive index of the first hollow glass tube 4 is greater than the refractive index of the second hollow glass tube 3 and the outer cladding 1, which can form a strong refractive index contrast, thereby ensuring that light can be effectively confined and reflected in the core. The refractive index of the second hollow glass tube 3 can be lower than or close to the refractive index of the outer cladding 1, which can ensure that the transmission of light between different structures will not cause significant reflection losses.

[0042] The core region 5 is a hollow core region filled with air in the center, located in the center of the optical fiber, and is mainly used for light propagation. The radius R of the core region 5 can be adjusted according to different application requirements, and is usually designed to be a few microns to hundreds of microns. The core region 5 achieves effective confinement and low-loss transmission of the optical mode field through precise coupling with the first hollow glass tube 4. The core region 5 is not only suitable for the transmission of high-power lasers, but also plays a key role in optical fiber sensing, and can transmit signals under conditions of high sensitivity and low noise.

[0043] In summary, the present invention can effectively disperse the mechanical stress applied by the outside world and avoid structural deformation of the antiresonance layer (inner cladding) due to stress concentration by designing multiple support bodies 2 that are tightly fitted to the inner wall of the outer cladding 1. At the same time, by designing the wall thickness and diameter of the first hollow glass tube 4 and the second hollow glass tube 3, light waves can be transmitted with low loss within a specific wavelength range. Combined with the high-strength outer cladding 1, the optical fiber structure of the present invention can still maintain stable optical performance and structural integrity under harsh environments such as external pressure, bending and vibration.

[0044] The present invention combines the advantages of the support body 2 and the hollow anti-resonant glass tube, not only providing excellent mechanical properties and thermal stability, but also significantly reducing the transmission loss and nonlinear effect of the optical fiber through precise anti-resonant structure design. Therefore, the optical fiber is particularly suitable for application scenarios such as long-distance low-loss optical communication, high-power laser transmission and optical fiber sensing, and can maintain high-performance optical transmission characteristics under complex environmental conditions.

[0045] Example 1

[0046] This embodiment is in the above Figure 1 The size is limited based on the structure, the outer cladding 1 is made of silica, with an inner diameter of 120μm and a thickness of 55μm; the support body 2 is made of calcium-doped silica, with a refractive index of 1.55 and a diameter of 10μm; the first hollow glass tube 3 is 7μm in diameter, 1μm in wall thickness, made of silica, and has a refractive index of 1.40; the second hollow glass tube 4 has a diameter of 30μm, a wall thickness of 1μm, made of silica, and has a refractive index of 1.50.

[0047] Please refer to Figure 2-Figure 4 , respectively showing the effective refractive index, confinement loss and bending loss curves of this embodiment as the wavelength varies.

[0048] Example 2

[0049] This embodiment is in the above Figure 1The size is limited based on the structure, the outer cladding 1 is made of silica, with an inner diameter of 125μm and a thickness of 58μm; the support body 2 is made of aluminosilicate glass, with a refractive index of 1.6 and a diameter of 12μm; the second hollow glass tube 3 is 6μm in diameter, 0.8μm in wall thickness, made of silica, and has a refractive index of 1.38; the first hollow glass tube 4 has a diameter of 25μm, a wall thickness of 0.8μm, made of silica, and has a refractive index of 1.52.

[0050] Therefore, the present invention effectively overcomes various shortcomings in the prior art and has a high industrial utilization value. The above embodiments are only illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the technology can modify or change the above embodiments without violating the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. An enhanced stress-resistant hollow-core antiresonant optical fiber, characterized in that: include A plurality of supports are arranged in a ring array between the outer cladding and the inner cladding; The inner cladding comprises a first hollow glass tube, which covers the core region and has an outer side tangent to the support body.

2. The enhanced stress-resistant hollow-core antiresonant optical fiber according to claim 1, characterized in that: The support body is tangent to the inner side of the outer cladding layer, and two adjacent support bodies are arranged in contact with each other.

3. The enhanced stress-resistant hollow-core antiresonant optical fiber according to claim 1, characterized in that: The support body is tangent to the inner side of the outer cladding layer, and two adjacent support bodies are spaced apart, with the spacing distance not exceeding the radius of the support body.

4. The stress-resistant hollow-core antiresonant optical fiber according to any one of claims 1 to 3, characterized in that: The support body is a solid cylindrical structure, and is made of silicon dioxide doped with specific elements, wherein the specific elements include calcium, magnesium, aluminum, boron or phosphorus.

5. The enhanced stress-resistant hollow-core antiresonant optical fiber according to any one of claim 1, characterized in that: A line connecting the center of the first hollow glass tube and the support body tangent thereto passes through the center of the core region.

6. The enhanced stress-resistant hollow-core antiresonant optical fiber according to claim 1, characterized in that: The inner cladding also includes a second hollow glass tube, which is disposed between the support body and the first hollow glass tube and is tangent to the support body and does not contact the first hollow glass tube.

7. The enhanced stress-resistant hollow-core antiresonant optical fiber according to claim 6, characterized in that: The distance between the second hollow glass tube and the first hollow glass tube is equivalent to the wall thickness of the second hollow glass tube.

8. The enhanced stress-resistant hollow-core antiresonant optical fiber according to claim 6, characterized in that: The second hollow glass tube is spaced apart from the first hollow glass tube.

9. The enhanced stress-resistant hollow-core antiresonant optical fiber according to claim 6, characterized in that: The refractive index of the first hollow glass tube is greater than the refractive index of the outer cladding, and the refractive index of the outer cladding is not less than the refractive index of the second hollow glass tube.

10. The enhanced stress-resistant hollow-core antiresonant optical fiber according to claim 6, characterized in that: A line connecting the center of the second hollow glass tube and the support body tangent thereto passes through the center of the core region.

Images