Hollow-core anti-resonance optical fiber

Abstract

The invention relates to a hollow-core anti-resonance optical fiber. The hollow-core anti-resonance optical fiber comprises an outer cladding, an anti-resonance region and a fiber core region, the anti-resonance area comprises a plurality of nesting units, each nesting unit comprises a first anti-resonance tube and a second anti-resonance tube, the first anti-resonance tubes are connected with the outer cladding, the second anti-resonance tubes are connected with the first anti-resonance tubes, and the included angle theta between the first plane and the second plane of each nesting unit is larger than or equal to 0 degree and smaller than 180 degrees. The first plane is a plane formed by the central axis of the first anti-resonance tube and the central axis of the second anti-resonance tube in the first anti-resonance tube, and the second plane is a plane formed by the central axis of the first anti-resonance tube and the central axis of the outer cladding layer; the fiber core area comprises an area surrounded by the first anti-resonance tube and the boundary of the outer cladding. According to the hollow-core anti-resonance optical fiber, low loss is achieved, meanwhile, the structural symmetry of an existing hollow-core anti-resonance optical fiber is broken, the position structure of an optical fiber resonance ring junction does not need to be accurately controlled, the preparation difficulty of the optical fiber is reduced, and large-scale production of the optical fiber is facilitated.

Description

Technical Field

[0001] The present application relates to the field of optical communication technology, and in particular to a hollow core anti-resonant optical fiber. Background Art

[0002] With the increase in communication capacity demand and the special requirements for fiber link performance in specific communication scenarios, the performance of traditional solid-core optical fibers has reached its limit. Traditional quartz optical fibers cannot meet the performance requirements of low attenuation, low latency, low nonlinearity, low dispersion, and high bandwidth, which is a bottleneck restricting the continued development of optical fiber communication technology.

[0003] Hollow-core antiresonant optical fiber is different from conventional optical fiber. It uses the antiresonance phenomenon to allow light to be transmitted in the low-refractive-index air core. Light transmitted in hollow-core optical fiber has the advantages of low latency, low loss, low dispersion, low nonlinearity, and high damage threshold. Compared with traditional optical fiber, hollow-core optical fiber has broad application prospects.

[0004] Although hollow-core antiresonant fibers have obvious performance advantages over ordinary optical fibers, the existing hollow-core antiresonant fibers have high structural symmetry requirements, and this special antiresonant structure greatly increases the difficulty of manufacturing optical fibers. Therefore, under the premise of meeting various performance requirements of hollow-core antiresonance, adjusting the geometric structure of hollow-core antiresonant fibers is conducive to the research and development of hollow-core antiresonant fibers. Summary of the invention

[0005] The embodiment of the present application provides a hollow-core antiresonant optical fiber, which reduces the difficulty of preparing the optical fiber while achieving the low-loss optical performance requirements, thereby facilitating the large-scale production of the optical fiber.

[0006] The embodiment of the present application provides a hollow core anti-resonant optical fiber, wherein the hollow core anti-resonant optical fiber comprises a cladding region, an anti-resonant region and a core region;

[0007] The cladding region includes an outer cladding;

[0008] The anti-resonance region includes a plurality of nested units spaced apart in the outer cladding, the nested units include a first anti-resonance tube and a second anti-resonance tube nested in the first anti-resonance tube, the first anti-resonance tube is connected to the outer cladding, the second anti-resonance tube is connected to the first anti-resonance tube, an angle θ between a first plane and a second plane of the nested unit is 0°≤θ<180°, the first plane is a plane formed by a central axis of the first anti-resonance tube and a central axis of the second anti-resonance tube therein, and the second plane is a plane formed by a central axis of the first anti-resonance tube and a central axis of the outer cladding;

[0009] The core region includes a region surrounded by a boundary between the first anti-resonance tube and the outer cladding.

[0010] In some embodiments, an angle θ between the first plane and the second plane is 90°≤θ≤177°.

[0011] In some embodiments, the angles θ between the first plane and the second plane of each nested unit are equal, or partially equal, or unequal.

[0012] In some embodiments, in the nested unit, when the central axis of the second anti-resonance tube is located on the left side of the second plane, it is recorded as the center position of the second anti-resonance tube rotates clockwise relative to the center of the first anti-resonance tube; when the central axis of the second anti-resonance tube is located on the right side of the second plane, it is recorded as the center position of the second anti-resonance tube rotates counterclockwise relative to the center of the first anti-resonance tube;

[0013] The second anti-resonance tubes of each of the nested units all rotate clockwise, or all rotate counterclockwise, or a part rotates clockwise and the other part rotates counterclockwise.

[0014] In some embodiments, the outer wall of the first anti-resonance tube is tangent to the inner wall of the outer cladding, and the outer wall of the second anti-resonance tube is tangent to the inner wall of the first anti-resonance tube.

[0015] In some embodiments, the outer wall of the first anti-resonance tube intersects with the inner wall of the outer cladding layer, so that the first anti-resonance tube is an arc-shaped tube;

[0016] The outer wall of the second anti-resonance tube intersects with the inner wall of the first anti-resonance tube, so that the second anti-resonance tube is an arc-shaped tube.

[0017] In some embodiments, the outer wall of the first anti-resonance tube intersects with the inner wall of the outer cladding layer to form a first overlapping region;

[0018] The outer wall of the second anti-resonance tube intersects with the inner wall of the first anti-resonance tube to form a second overlapping area;

[0019] The second overlapping region is located within the first overlapping region.

[0020] In some embodiments, the core region includes a core, wherein the core is a circular region formed by circumscribed circles that are simultaneously circumscribed to each of the first anti-resonance tubes, and the diameter of the core is 20 to 40 microns.

[0021] In some embodiments, the wall thickness of the first anti-resonance tube and the second anti-resonance tube is 0.3-1.6 microns.

[0022] In some embodiments, the outer diameter of the outer cladding is 150 to 300 microns.

[0023] The beneficial effects of the technical solution provided by this application include:

[0024] The hollow-core anti-resonant optical fiber provided in the embodiment of the present application breaks the structural symmetry of the existing hollow-core anti-resonant optical fiber while achieving the low-loss optical performance requirements. It does not require precise control of the position structure of the optical fiber resonant ring knot, reduces the difficulty of optical fiber preparation, and is conducive to large-scale production of optical fiber. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 Schematic diagram of a hollow-core antiresonant optical fiber provided in an embodiment of the present application (tangent);

[0027] Figure 2 Schematic diagram of a hollow-core antiresonant optical fiber provided in an embodiment of the present application (intersecting);

[0028] Figure 3 Provides a relationship curve between attenuation and wavelength at different angles for the embodiment of the present application;

[0029] Figure 4 Provide a mode field distribution at a wavelength of 1550nm when the angle is 145° for the embodiment of the present application;

[0030] Figure 5 A relationship curve between the mode field diameter and the wavelength at different angles is provided for the embodiment of the present application.

[0031] In the figure: 1. outer cladding; 2. first antiresonance tube; 3. second antiresonance tube; 4. first overlapping region; 5. second overlapping region; 6. fiber core. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0033] See also Figure 1 and Figure 2As shown, an embodiment of the present application provides a hollow-core antiresonant optical fiber, which includes a cladding region, an antiresonant region and a core region; wherein the cladding region includes an outer cladding 1, the antiresonant region includes a plurality of nested units spaced apart in the outer cladding 1, the nested units are distributed along the circumferential direction of the outer cladding 1, the nested units include a first antiresonant tube 2 and a second antiresonant tube 3 nested in the first antiresonant tube 2, the first antiresonant tube 2 is connected to the outer cladding 1, the second antiresonant tube 3 is connected to the first antiresonant tube 2, an angle θ between a first plane and a second plane of the nested unit is 0°≤θ<180°, the first plane is a plane formed by the central axis of the first antiresonant tube 2 and the central axis of the second antiresonant tube 3 therein, and the second plane is a plane formed by the central axis of the first antiresonant tube 2 and the central axis of the outer cladding 1; the core region includes a region surrounded by the boundary of the first antiresonant tube 2 and the outer cladding 1.

[0034] Specifically, see Figure 1 and Figure 2 As shown, the position of the central axis of the outer cladding 1 is recorded as point A, the position of the central axis of the first anti-resonance tube 2 is recorded as point B, the position of the central axis of the second anti-resonance tube 3 is recorded as point C, BC constitutes a first plane, BA constitutes a second plane, the outer wall of the second anti-resonance tube 3 is tangent to the inner wall of the first anti-resonance tube 2 at point D, and the outer wall of the first anti-resonance tube 2 is tangent to the inner wall of the outer cladding 1 at point E.

[0035] The second anti-resonance tube 3 moves in the first anti-resonance tube 2. When the central axis of the second anti-resonance tube 3 reaches point C', the angle θ between the first plane and the second plane is 180°. When the second anti-resonance tube 3 moves in the first anti-resonance tube 2 to the position where the central axis of the second anti-resonance tube 3 is located between point B and point A, and is located in the second plane, the angle θ between the first plane and the second plane is 0°.

[0036] It can be understood that the circle formed by the above-mentioned point B, point C and point C′ is the moving track of the central axis of the second anti-resonance tube 3 .

[0037] It can be understood that the number of the above nested units can be determined according to actual needs.

[0038] In the present application, the center of the second antiresonance tube 3 is not coplanar with the outer cladding 1 and the first antiresonance tube 2, so that the second antiresonance tube 3 has a certain rotational movement relative to the first antiresonance tube 2, which is asymmetrical. This breaks the structural symmetry of the existing hollow-core antiresonance optical fiber, and there is no need to precisely control the position structure of the optical fiber resonant ring knot, which reduces the difficulty of optical fiber preparation and is conducive to large-scale production of optical fiber.

[0039] Furthermore, the angle θ between the first plane and the second plane can be designed according to the actual performance required by the optical fiber. For example, as an example, the angle θ between the first plane and the second plane is 90°≤θ≤177°.

[0040] Furthermore, the above-mentioned nested units are distributed at equal intervals.

[0041] Furthermore, the angles θ between the first plane and the second plane of each nested unit are equal, or partially equal, or unequal.

[0042] Further, in the nested unit, when the central axis of the second anti-resonance tube 3 is located on the left side of the second plane, it is recorded as the center position of the second anti-resonance tube 3 rotates clockwise relative to the center of the first anti-resonance tube 2; when the central axis of the second anti-resonance tube 3 is located on the right side of the second plane, it is recorded as the center position of the second anti-resonance tube 3 rotates counterclockwise relative to the center of the first anti-resonance tube 2; the second anti-resonance tubes 3 of each nested unit all rotate clockwise, or all rotate counterclockwise, or one part rotates clockwise and the other part rotates counterclockwise.

[0043] As an example, see Figure 1 As shown, the top nested unit is the first nested unit and the nested units are sorted in a clockwise order.

[0044] For the first nested unit, ABE is used as the dividing line. At this time, point C is on the left side of the ABE dividing line, indicating that the center position of the second anti-resonance tube 3 of the first nested unit rotates clockwise relative to the center of the first anti-resonance tube 2.

[0045] For the second nested unit, the center position of the second anti-resonance tube 3 rotates counterclockwise relative to the center of the first anti-resonance tube 2 .

[0046] For the third nested unit, the center position of the second anti-resonance tube 3 rotates counterclockwise relative to the center of the first anti-resonance tube 2 .

[0047] For the fourth nested unit, the center position of the second anti-resonance tube 3 rotates counterclockwise relative to the center of the first anti-resonance tube 2 .

[0048] For the fifth nested unit, the center position of the second anti-resonance tube 3 rotates clockwise relative to the center of the first anti-resonance tube 2 .

[0049] Further, see Figure 1 As shown, the outer wall of the first anti-resonance tube 2 is tangent to the inner wall of the outer cladding 1, and the tangent point is point E. The outer wall of the second anti-resonance tube 3 is tangent to the inner wall of the first anti-resonance tube 2, and the tangent point is point D. Obviously, since the angle θ between the first plane and the second plane is 0°≤θ<180°, point E and point D do not coincide.

[0050] Further, see Figure 2 As shown, the outer wall of the first anti-resonance tube 2 intersects with the inner wall of the outer cladding 1, so that the first anti-resonance tube 2 is an arc-shaped tube; the outer wall of the second anti-resonance tube 3 intersects with the inner wall of the first anti-resonance tube 2, so that the second anti-resonance tube 3 is an arc-shaped tube.

[0051] Further, see Figure 2 As shown, the outer wall of the first antiresonance tube 2 intersects with the inner wall of the outer cladding 1 to form a first overlapping region 4; the outer wall of the second antiresonance tube 3 intersects with the inner wall of the first antiresonance tube 2 to form a second overlapping region 5; the second overlapping region 5 is located in the first overlapping region 4.

[0052] Further, see Figure 1 As shown, the core region includes a core 6, and the core 6 is a circular region formed by circumscribed circles that are simultaneously circumscribed to each of the first anti-resonance tubes 2, and the diameter of the core 6 is 20 to 40 microns, preferably 30 microns.

[0053] Furthermore, the wall thickness of the first anti-resonance tube 2 and the second anti-resonance tube 3 is 0.3-1.6 microns, preferably 0.4 microns.

[0054] Furthermore, the outer diameter of the outer cladding 1 is 150-300 microns, preferably 250 microns.

[0055] When the wall thicknesses of the first antiresonance tube 2 and the second antiresonance tube 3 satisfy the antiresonance formula of destructive interference, low-loss propagation of the antiresonance optical fiber can be achieved.

[0056] It can be understood that the outer cladding 1, the first anti-resonance tube 2, and the second anti-resonance tube 3 can all adopt a glass tube structure, such as a capillary tube.

[0057] It is understandable that the core region may be filled with air, the outer cladding 1 may be filled with air, the first anti-resonance tube 2 may be filled with air, and the second anti-resonance tube 3 may be filled with air.

[0058] Example

[0059] A hollow-core antiresonant optical fiber, comprising a cladding region, an antiresonant region and a core region, wherein the cladding region comprises an outer cladding 1, the antiresonant region comprises 5 nested units equally spaced within the outer cladding 1, the nested units comprise a first antiresonant tube 2 and a second antiresonant tube 3 nested within the first antiresonant tube 2, the first antiresonant tube 2 is tangent to the outer cladding 1, the second antiresonant tube 3 is tangent to the first antiresonant tube 2, an angle between a first plane and a second plane of the nested unit is θ, the first plane is a plane formed by a central axis of the first antiresonant tube 2 and a central axis of the second antiresonant tube 3 therein, and the second plane is a plane formed by a central axis of the first antiresonant tube 2 and a central axis of the outer cladding 1; the core region comprises a region surrounded by a boundary between the first antiresonant tube 2 and the outer cladding 1.

[0060] The outer cladding 1 and the first anti-resonance tube 2 and the second anti-resonance tube 3 are made of silicon dioxide, and the other regions are air.

[0061] The diameter of the fiber core 6 is 30 microns, the wall thickness of the first anti-resonance tube 2 and the second anti-resonance tube 3 is 0.4 microns, and the outer diameter of the outer cladding 1 is 250 microns.

[0062] The mode of the optical fiber in this embodiment is simulated by finite element software, and the relationship curves of the mode field distribution, limiting loss, mode field diameter and corresponding wavelength of the hollow core antiresonant optical fiber at different θ angles are calculated, as shown in FIG. Figure 3 , Figure 4 and Figure 5 shown.

[0063] From the attenuation versus wavelength curve, it can be seen that when 135°≤θ<180°, the maximum attenuation is less than 0.03dB / km, and when θ is 90°≤θ<135°, the maximum attenuation is less than 0.3dB / km.

[0064] It can be seen from the figure that the hollow-core anti-resonant optical fiber provided in the embodiment has the characteristic of low limiting loss in the C+L communication band.

[0065] It can also be seen that the optical fiber mode energy of the corresponding structure in the embodiment is concentrated in the core area.

[0066] It can be seen that the hollow-core anti-resonant optical fiber provided in the present application, while achieving the low-loss optical performance requirements, breaks the structural symmetry of the existing hollow-core anti-resonant optical fiber, does not require precise control of the position structure of the optical fiber resonant ring knot, reduces the difficulty of optical fiber preparation, and is conducive to large-scale production of optical fiber.

[0067] In the description of the present application, it should be noted that the terms "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0068] It should be noted that, in this application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0069] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A hollow core antiresonant optical fiber, characterized in that: The hollow core anti-resonance optical fiber comprises a cladding region, an anti-resonance region and a core region; The cladding region includes an outer cladding (1); The anti-resonance region comprises a plurality of nested units which are spaced apart and distributed in the outer cladding (1); the nested units comprise a first anti-resonance tube (2) and a second anti-resonance tube (3) nested in the first anti-resonance tube (2); the first anti-resonance tube (2) is connected to the outer cladding (1); the second anti-resonance tube (3) is connected to the first anti-resonance tube (2); an angle θ between a first plane and a second plane of the nested unit is 0°≤θ<180°; the first plane is a plane formed by a central axis of the first anti-resonance tube (2) and a central axis of the second anti-resonance tube (3) therein; and the second plane is a plane formed by a central axis of the first anti-resonance tube (2) and a central axis of the outer cladding (1); The core region includes a region surrounded by a boundary between the first anti-resonance tube (2) and the outer cladding (1).

2. The hollow core antiresonant optical fiber according to claim 1, characterized in that: An included angle θ between the first plane and the second plane is 90°≤θ≤177°.

3. The hollow core antiresonant optical fiber according to claim 1, wherein: The included angles θ between the first plane and the second plane of each nested unit are equal, or partially equal, or unequal.

4. The hollow core antiresonant optical fiber according to claim 1, wherein: In the nested unit, when the center axis of the second anti-resonance tube (3) is located on the left side of the second plane, it is recorded that the center position of the second anti-resonance tube (3) rotates clockwise relative to the center of the first anti-resonance tube (2); when the center axis of the second anti-resonance tube (3) is located on the right side of the second plane, it is recorded that the center position of the second anti-resonance tube (3) rotates counterclockwise relative to the center of the first anti-resonance tube (2); The second anti-resonance tubes (3) of each nested unit all rotate clockwise, or all rotate counterclockwise, or a part rotates clockwise and the other part rotates counterclockwise.

5. The hollow core antiresonant optical fiber according to claim 1, wherein: The outer wall of the first anti-resonance tube (2) is tangent to the inner wall of the outer cladding (1), and the outer wall of the second anti-resonance tube (3) is tangent to the inner wall of the first anti-resonance tube (2).

6. The hollow core antiresonant optical fiber according to claim 1, wherein: The outer wall of the first anti-resonance tube (2) intersects with the inner wall of the outer cladding (1), so that the first anti-resonance tube (2) is an arc-shaped tube; The outer wall of the second anti-resonance tube (3) intersects with the inner wall of the first anti-resonance tube (2), so that the second anti-resonance tube (3) is an arc-shaped tube.

7. The hollow core antiresonant optical fiber according to claim 6, characterized in that: The outer wall of the first anti-resonance tube (2) intersects with the inner wall of the outer cladding (1) to form a first overlapping region (4); The outer wall of the second anti-resonance tube (3) intersects with the inner wall of the first anti-resonance tube (2) to form a second overlapping area (5); The second overlapping region (5) is located within the first overlapping region (4).

8. The hollow core antiresonant optical fiber according to claim 1, wherein: The core region includes a core (6), wherein the core (6) is a circular region formed by circumscribed circles that are simultaneously circumscribed to each of the first anti-resonance tubes (2), and the diameter of the core (6) is 20 to 40 microns.

9. The hollow core antiresonant optical fiber according to claim 1, wherein: The wall thickness of the first anti-resonance tube (2) and the second anti-resonance tube (3) is 0.3 to 1.6 micrometers.

10. The hollow core antiresonant optical fiber according to claim 1, characterized in that: The outer diameter of the outer cladding (1) is 150 to 300 microns.

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