Hollow-core microstructure optical fiber with positioning surface and manufacturing method of hollow-core microstructure optical fiber

Abstract

The invention discloses a hollow-core microstructure optical fiber with a positioning surface and a manufacturing method of the hollow-core microstructure optical fiber. The optical fiber comprises a sleeve cladding, a plurality of anti-resonance microstructure units and a coating, the outer contour of the cross section of the sleeve cladding is circular; the plurality of anti-resonance microstructure units are distributed on the inner side of the sleeve cladding; the coating is externally coated on the sleeve wrapping layer; the coating is provided with at least one positioning surface, so that the outer contour of the cross section of the hollow-core microstructure optical fiber is non-circular, and the positioning surface is consistent with the relative positions of the plurality of anti-resonance microstructure units in the length direction. According to the hollow-core microstructure optical fiber with the positioning surface, the orientation of the end face of the hollow-core microstructure optical fiber is marked through the coating positioning surface, the perfect and symmetrical circular structure of the end face of the optical fiber is damaged, end face matching of the optical fiber to be welded is achieved through positioning surface matching, and anti-resonance units of the hollow-core microstructure optical fiber are matched and welded rapidly and accurately; the welding efficiency is improved; and the welding loss is reduced.

Description

Technical Field

[0001] The present invention belongs to the field of optical communication, and more specifically, relates to a hollow microstructure optical fiber with a positioning surface and a manufacturing method thereof. Background Art

[0002] Hollow microstructure optical fibers have ultra-low loss, low dispersion, low non-linearity, and a propagation speed close to the speed of light. With the in-depth research on hollow microstructure optical fibers based on the anti-resonance principle, under reasonable structural design, hollow microstructure optical fibers can effectively reduce transmission loss, have the potential to be used as ultra-long-distance communication optical fibers, and have the prospect of large-scale application. They are recognized as the optical fibers for the next-generation ultra-large-capacity, low-latency, and high-speed optical communication systems.

[0003] The technical research on hollow microstructure optical fibers is mainly based on the reasonable design of nested structures, the precise positioning of anti-resonance units during the manufacturing process, and how to achieve axial uniformity. Currently, hollow microstructure optical fibers mainly use anti-resonance microstructure units to fabricate anti-resonance claddings. When hollow microstructure optical fibers are spliced, it is necessary to match each microstructure unit, otherwise the splicing loss is obvious. Currently, some end-face detection methods are used to align the end-faces of hollow microstructure optical fibers so that each microstructure unit matches.

[0004] These methods are currently applied to the splicing and matching of optical fibers such as polarization-maintaining optical fibers. Although they are theoretically reasonable for anti-resonance optical fibers, due to the good rotational symmetry of anti-resonance units, their registration difficulty far exceeds that of polarization-maintaining optical fibers, and they have high precision requirements. The current splicing means have low splicing efficiency and large splicing loss, and it is difficult to fabricate on a large scale. Summary of the Invention

[0005] In view of the above-mentioned defects or improvement requirements of the prior art, the present invention provides a hollow microstructure optical fiber with a positioning surface and a manufacturing method thereof. The purpose is to mark the azimuth information of the fiber end-face through the positioning surface of the outer coating. When the positioning surfaces match, the end-faces are aligned, so as to conveniently and quickly match each microstructure unit of the hollow microstructure optical fiber, reduce the splicing loss, and improve the splicing efficiency, thereby solving the technical problem that the existing hollow microstructure optical fibers are difficult to achieve precise end-face registration, resulting in large splicing loss and low efficiency.

[0006] To achieve the above object, according to one aspect of the present invention, there is provided a hollow microstructure optical fiber with a positioning surface, including a sleeve cladding, a plurality of anti-resonance microstructure units, and a coating;

[0007] The outer contour of the cross-section of the sleeve cladding is circular;

[0008] The plurality of anti-resonance microstructure units are distributed inside the sleeve cladding;

[0009] The coating is externally coated on the sleeve cladding;

[0010] The coating has at least one positioning surface such that the outer contour of the cross-section of the hollow microstructure optical fiber is non-circular, and the relative positions of the positioning surface and the plurality of anti-resonant microstructure units are consistent in the length direction.

[0011] Preferably, for the hollow microstructure optical fiber with a positioning surface, the positioning surface is a straight line on the cross-section of the hollow microstructure optical fiber.

[0012] Preferably, for the hollow microstructure optical fiber with a positioning surface, the coating has a pair of mutually parallel positioning surfaces; or

[0013] The coating has a plurality of positioning surfaces at a preset included angle.

[0014] Preferably, for the hollow microstructure optical fiber with a positioning surface, the outer contour of the cross-section of the coating is D-shaped, runway-shaped, sectoroid-shaped or U-shaped.

[0015] Preferably, for the hollow microstructure optical fiber with a positioning surface, the coating has a multi-layer structure.

[0016] Preferably, for the hollow microstructure optical fiber with a positioning surface, the sleeve or the inner side of the sleeve of the anti-resonant microstructure optical fiber has a mark, and the mark makes the end face of the hollow microstructure optical fiber have asymmetry.

[0017] According to another aspect of the present invention, there is provided a method for manufacturing the hollow microstructure optical fiber with a positioning surface, including the following steps:

[0018] The bare fiber of the hollow microstructure optical fiber obtained by wire drawing is coated one or more times through a coating die and cured and formed;

[0019] The last coating enables the optical fiber to pass through a special-shaped coating die in a preset posture, and the cross-section of the coating die has a positioning edge.

[0020] Preferably, for the method for manufacturing the hollow microstructure optical fiber with a positioning surface, the coating die has a pair of mutually parallel positioning edges; or

[0021] The coating die has a plurality of positioning edges at a preset included angle.

[0022] Preferably, for the method for manufacturing the hollow microstructure optical fiber with a positioning surface, the cross-section of the coating die is D-shaped, runway-shaped, sectoroid-shaped or U-shaped.

[0023] Preferably, for the method for manufacturing the hollow microstructure optical fiber with a positioning surface, the sleeve or the inner side of the sleeve of the anti-resonant microstructure optical fiber has a mark, and the mark makes the end face of the hollow microstructure optical fiber have asymmetry;

[0024] By positioning the mark such that the optical fiber passes through the profiled coating die in a preset attitude.

[0025] Generally speaking, compared with the prior art, the above technical solutions conceived by the present invention can achieve the following beneficial effects:

[0026] The hollow microstructure optical fiber with a positioning surface provided by the present invention marks the orientation of the end face of the hollow microstructure optical fiber through the coating positioning surface, destroys the perfectly symmetric circular structure of the optical fiber end face, and realizes the end face matching of the optical fibers to be fused by using the positioning surface matching, so that the anti-resonant units of the hollow microstructure optical fiber are quickly and accurately matched and fused, improving the fusion efficiency and reducing the fusion loss.

[0027] In a preferred embodiment, the hollow microstructure optical fiber has a mark, making the structure of the optical fiber end face asymmetric. The geometric positional relationship between the mark and the coating always remains consistent in the optical fiber length direction, thus conveniently ensuring that the coating positioning surface and the optical fiber end face are in the same orientation. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 FIG. is a schematic structural diagram of a hollow microstructure optical fiber with additive-assisted positioning on the inner wall of the cladding and a D-shaped outer contour provided by the present invention;

[0029] Figure 2 FIG. is a schematic structural diagram of a hollow microstructure optical fiber with subtractive-assisted positioning on the inner wall of the cladding and a D-shaped outer contour provided by the present invention

[0030] Figure 3 FIG. is a schematic structural diagram of a hollow microstructure optical fiber with additive-assisted positioning on the inner wall of the cladding and a runway-shaped outer contour provided by the present invention;

[0031] Figure 4 FIG. is a schematic structural diagram of a hollow microstructure optical fiber with subtractive-assisted positioning on the inner wall of the cladding and a runway-shaped outer contour provided by the present invention;

[0032] Figure 5 FIG. is a schematic structural diagram of a hollow microstructure optical fiber with additive-assisted positioning on the inner wall of the cladding and a positioning surface with a preset included angle on the outer contour provided by the present invention;

[0033] Figure 6 FIG. is a schematic structural diagram of a hollow microstructure optical fiber with subtractive-assisted positioning on the inner wall of the cladding and a positioning surface with a preset included angle on the outer contour provided by the present invention;

[0034] Figure 7 FIG. is a schematic structural diagram of a hollow microstructure optical fiber with additive-assisted positioning on the inner wall of the cladding and a C-shaped outer contour provided by the present invention;

[0035] Figure 8It is a schematic diagram of a hollow microstructure optical fiber provided by the present invention, with a subtractive-assisted positioning on the inner wall of the cladding and a U-shaped outer contour.

[0036] In all the drawings, the same reference numerals are used to represent the same elements or structures, where: 1 is the sleeve cladding, 2 is the first anti-resonant cladding ring of the anti-resonant microstructure unit, 3 is the second anti-resonant cladding ring of the anti-resonant microstructure unit, 4 is the mark, 5 is the coating, 6 is the positioning surface, and 7 is the core region. Detailed implementation manners

[0037] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0038] The hollow microstructure optical fiber provided by the present invention includes a sleeve cladding, a plurality of anti-resonant microstructure units, and a coating; the plurality of anti-resonant microstructure units are distributed inside the sleeve cladding; the coating is externally coated on the sleeve cladding;

[0039] The sleeve cladding is generally made of glass, and its outer contour of the cross-section is circular; the sleeve or the inside of the sleeve of the anti-resonant microstructure optical fiber has a mark, and the mark makes the end face of the hollow microstructure optical fiber have asymmetry. Since the glass part and the coating part of the optical fiber are formed separately, in order to register the outer contour of the coating with the internal structure of the anti-resonant microstructure optical fiber, it is necessary to mark the anti-resonant microstructure unit. The mark makes the end face of the hollow microstructure optical fiber have asymmetry. As long as the mark is registered with the structure of the outer contour and the relative position is fixed, it can ensure the registration of the anti-resonant microstructure unit with the outer contour of the coating, so as to ensure that the relative position of the positioning surface in the length direction is consistent with that of the plurality of anti-resonant microstructure units. When using the anti-resonant microstructure optical fiber, the plurality of microstructure units inside the anti-resonant microstructure optical fiber can be positioned through the positioning surface of the coating.

[0040] The mark has recognizable contour in the end face image of the hollow microstructure optical fiber, and can be a refractive index mark, a wavelength mark, or a structure mark;

[0041] The refractive index mark is the glass part in the glass part of the optical fiber where the refractive index of the material is different from that of its surrounding materials. Due to the difference in refractive index from that of the surrounding materials, its contour can be recognized in the end face image of the hollow microstructure optical fiber when imaging in transmitted light or reflected light, and has recognizable degree;

[0042] The wavelength marker is a glass part in the optical fiber glass section with different light transmittance for lights of different wavelengths from that of the surrounding materials. When its contour is imaged under illumination of lights of different wavelengths or mixed light, it can be recognized in the end-face image of the hollow microstructure optical fiber and has recognizability.

[0043] The structure marker has recognizability in the end-face image in terms of its shape and structure, including an additive structure and a subtractive structure of the hollow microstructure optical fiber cladding, so as to increase the asymmetry of the cladding and achieve the purpose of recognition. The additive structure of the hollow microstructure optical fiber cladding, such as markers like tubes, rods, ribs added to the cladding; the subtractive structure of the hollow microstructure optical fiber cladding, such as marked structures like grooves and drill holes.

[0044] The coating has at least one positioning surface such that the outer contour of the cross-section of the hollow microstructure optical fiber is non-circular, and the relative position of the positioning surface in the length direction is consistent with that of the multiple anti-resonant microstructure units. In the hollow microstructure optical fiber, multiple microstructures form a microstructure cladding, thereby restricting the distribution of light energy in the air core part. When optical fibers are fusion-spliced, if the multiple microstructure units cannot be better registered and the azimuth difference between the microstructure optical fibers to be fusion-spliced is relatively large, it will cause obvious fusion-splicing loss. The present invention uses the positioning surface to mark the azimuth difference between the optical fibers to be fusion-spliced. The positioning surface keeps a consistent relative position with the internal structure of the optical fiber, facilitating the recognition of the azimuth of the optical fiber. When the positioning surfaces between the optical fibers to be fusion-spliced match, it can be considered that the azimuths of the optical fibers to be fusion-spliced also match, and the microstructure units are registered, thereby reducing the fusion-splicing loss.

[0045] In a preferred solution, the positioning surface is a straight line on the cross-section of the hollow microstructure optical fiber, which is easy to recognize and fixed in a specific azimuth.

[0046] In some embodiments, the coating has a pair of mutually parallel positioning surfaces. For the hollow microstructure optical fiber with mutually parallel positioning surfaces, the optical fibers can be conveniently aligned through the mutual registration of the positioning surfaces for making optical fiber ribbons or optical devices; typically, such as a coating with a runway-shaped cross-section outer contour.

[0047] In some embodiments, the coating has multiple positioning surfaces at a preset included angle, and preferably the coating has two orthogonal positioning surfaces. The positioning surfaces at a preset included angle can fix the position of the optical fiber end-face from multiple dimensions, enabling the optical fiber to be fixed at a preset position and in a preset posture in the space plane, thereby ensuring the registration during optical fiber fusion-splicing and facilitating the adjustment of the spatial posture of the optical fiber, which is convenient for the manufacture of optical fiber devices; typically, such as a coating with a quasi-sector-shaped cross-section outer contour.

[0048] Generally, the coating has a multi-layer structure, which is formed by applying and curing a photocurable resin multiple times, and has functions such as support, protection, and coloring; the structure on the outermost side of the coating forms a preset contour.

[0049] The method for preparing a hollow microstructure optical fiber with a positioning surface according to the present invention includes the following steps:

[0050] The bare fiber of the hollow microstructure optical fiber obtained by wire drawing is coated and cured one or more times through a coating die;

[0051] In the last coating, the optical fiber passes through a special-shaped coating die in a preset posture, and the cross-section of the coating die has a positioning edge. The coating die has a pair of parallel positioning edges, typically an outer contour in the shape of a runway; or the coating die has multiple positioning edges at a preset included angle, typically an outer contour in the shape of a sector-like.

[0052] In a preferred solution, the sleeve of the anti-resonant microstructure optical fiber or the inner side of the sleeve has a mark, and the mark makes the end face of the hollow microstructure optical fiber have asymmetry; by positioning the mark, the optical fiber passes through the special-shaped coating die in a preset posture, so as to ensure that the relative position between the positioning surface and the mark remains consistent in the length direction, thereby ensuring that the relative position between the positioning surface and the multiple anti-resonant microstructure units remains consistent in the length direction.

[0053] The following are embodiments:

[0054] Embodiment 1

[0055] See Figure 1 , the hollow microstructure optical fiber with a positioning surface provided in this embodiment includes a sleeve cladding, multiple anti-resonant microstructure units, and a coating; the outer contour of the cross-section of the sleeve cladding is circular; the multiple anti-resonant microstructure units are distributed inside the sleeve cladding; the coating is covered on the sleeve cladding;

[0056] There is an additive-assisted positioning mark 4 on the inner wall of the sleeve cladding, the outer contour of the coating is D-shaped, and it has a planar positioning surface 6. Five anti-resonant microstructure units and an asymmetric additive-assisted positioning mark 4 are arranged inside the sleeve cladding. The anti-resonant microstructure unit has a first anti-resonant cladding ring 2 and a second anti-resonant cladding ring 3 nested inside the first anti-resonant ring. The sleeve cladding 1 is wrapped with a coating 5 having a positioning surface. The positioning surface 6 has asymmetry with the end face of the hollow microstructure optical fiber, and it has a definite geometric position relationship with the additive-assisted positioning mark 4 on the inner wall of the cladding and the first anti-resonant cladding ring 2. The first anti-resonant cladding rings 2 are spaced apart from each other and are evenly distributed in the circumferential direction, and enclose to form a core region 7.

[0057] The hollow microstructure optical fiber provided in this embodiment is prepared according to the following method:

[0058] The bare hollow microstructure optical fiber obtained by wire drawing is coated one or more times through a coating die. The last coating fixes the position of the optical fiber with a mark. The mark 4 is adjusted to the same position, and the bare optical fiber passes through the D-shaped coating die in a preset posture, and is cured to form a coating 5 with a D-shaped profile, thus obtaining the hollow microstructure optical fiber provided in this embodiment.

[0059] Embodiment 2

[0060] See Figure 2 , the hollow microstructure optical fiber with a positioning surface provided in this embodiment is similar to that in Embodiment 1, except that the mark is a subtractive-assisted positioning mark 4.

[0061] Embodiment 3

[0062] See Figure 3 , the hollow microstructure optical fiber with a positioning surface provided in this embodiment includes a sleeve cladding, a plurality of anti-resonant microstructure units, and a coating; the outer contour of the cross-section of the sleeve cladding is circular; the plurality of anti-resonant microstructure units are distributed inside the sleeve cladding; the coating is covered outside the sleeve cladding;

[0063] There is an additive-assisted positioning mark 4 on the inner wall of the sleeve cladding. The outer contour of the coating is runway-shaped and has a pair of parallel positioning surfaces 6. Five anti-resonant microstructure units and an asymmetric additive-assisted positioning mark 4 are arranged inside the sleeve cladding. The anti-resonant microstructure unit has a first anti-resonant cladding ring 2 and a second anti-resonant cladding ring 3 nested inside the first anti-resonant ring. The sleeve cladding 1 is wrapped with a coating 5 having a positioning surface. The positioning surface 6 has asymmetry with respect to the end face of the hollow microstructure optical fiber, and there is a definite geometric positional relationship between the positioning surface, the additive-assisted positioning mark 4 on the inner wall of the cladding, and the first anti-resonant cladding ring 2. The first anti-resonant cladding rings 2 are spaced apart from each other and are evenly circumferentially distributed, and enclose to form a core region 7.

[0064] The hollow microstructure optical fiber provided in this embodiment is prepared according to the following method:

[0065] The bare hollow microstructure optical fiber obtained by wire drawing is coated one or more times through a coating die. The last coating fixes the position of the optical fiber with a mark. The mark 4 is adjusted to the same position, and the bare optical fiber passes through the runway-shaped coating die in a preset posture, and is cured to form a coating 5 with a runway-shaped profile, thus obtaining the hollow microstructure optical fiber provided in this embodiment.

[0066] Embodiment 4

[0067] See Figure 4, the hollow microstructure optical fiber with a positioning surface provided in this embodiment is similar to that in Embodiment 4, except that the marking adopts a subtractive-assisted positioning mark.

[0068] Embodiment 5

[0069] See Figure 5 , the hollow microstructure optical fiber with a positioning surface provided in this embodiment includes a sleeve cladding, a plurality of anti-resonant microstructure units, and a coating; the outer contour of the cross-section of the sleeve cladding is circular; the plurality of anti-resonant microstructure units are distributed inside the sleeve cladding; the coating is coated on the sleeve cladding;

[0070] The inner wall of the sleeve cladding has an additive-assisted positioning mark 4, the outer contour of the coating is quasi-sector-shaped, and the hollow microstructure optical fiber has a plurality of positioning surfaces with a preset included angle. In this embodiment, orthogonal positioning surfaces are adopted. Five anti-resonant microstructure units and an asymmetric additive-assisted positioning mark 4 are arranged inside the sleeve cladding. The anti-resonant microstructure unit has a first anti-resonant cladding ring 2 and a second anti-resonant cladding ring 3 nested inside the first anti-resonant ring. The sleeve cladding 1 is wrapped with a coating 5 having a positioning surface. The positioning surface 6 has asymmetry with the end face of the hollow microstructure optical fiber, and there is a definite geometric position relationship between it and the additive-assisted positioning mark 4 on the inner wall of the cladding and the first anti-resonant cladding ring 2. The first anti-resonant cladding rings 2 are spaced apart from each other and are evenly distributed circumferentially, and enclose to form a core region 7.

[0071] The hollow microstructure optical fiber provided in this embodiment is prepared according to the following method:

[0072] The bare fiber of the hollow microstructure optical fiber obtained by wire drawing is coated one or more times through a coating die. The last coating makes the optical fiber fixed in position by using a mark, adjusts the mark 4 to the same position, and makes the bare fiber pass through the quasi-sector-shaped coating die in a preset posture, and cures to form a coating 5 with a quasi-sector-shaped contour, thus obtaining the hollow microstructure optical fiber provided in this embodiment.

[0073] Embodiment 6

[0074] See Figure 6 , the hollow microstructure optical fiber with a positioning surface provided in this embodiment is similar to that in Embodiment 5, except that the marking adopts a subtractive-assisted positioning mark.

[0075] Embodiment 7

[0076] See Figure 7 , the hollow microstructure optical fiber with a positioning surface provided in this embodiment includes a sleeve cladding, a plurality of anti-resonant microstructure units, and a coating; the outer contour of the cross-section of the sleeve cladding is circular; the plurality of anti-resonant microstructure units are distributed inside the sleeve cladding; the coating is coated on the sleeve cladding;

[0077] The inner wall of the sleeve cladding has an additive-assisted positioning mark 4, the outer contour of the coating is "匚"-shaped, and the hollow-core microstructure optical fiber has three positioning surfaces. In this embodiment, there is a pair of parallel positioning surfaces, which are orthogonal to the other positioning surface. Five anti-resonance microstructure units and asymmetric additive-assisted positioning marks 4 are arranged in the sleeve cladding. The anti-resonance microstructure unit has a first anti-resonance cladding ring 2 and a second anti-resonance cladding ring 3 nested in the first anti-resonance ring. The sleeve cladding 1 is wrapped with a coating 5 with a positioning surface. The positioning surface 6 is asymmetric with the end face of the hollow-core microstructure optical fiber, and has a definite geometric position relationship with the additive-assisted positioning mark 4 on the inner wall of the cladding and the first anti-resonance cladding ring 2. The first anti-resonance cladding rings 2 are spaced from each other, evenly distributed circumferentially, and surround to form a core region 7.

[0078] The hollow core microstructure optical fiber provided in this embodiment is prepared according to the following method:

[0079] The bare optical fiber of the hollow-core microstructure optical fiber obtained by drawing is coated once or multiple times through a coating mold. The last coating makes the optical fiber fixed in position by a mark. The mark 4 is adjusted to the same position, and the bare optical fiber passes through the 匚-shaped coating mold in a preset posture, and is solidified to form a coating 5 with a 匚-shaped contour, thereby obtaining the hollow-core microstructure optical fiber provided in this embodiment.

[0080] Example 8

[0081] See also Figure 8 The hollow core microstructure optical fiber with a positioning surface provided in this embodiment is similar to that in Embodiment 7, except that the marking adopts a subtractive auxiliary positioning marking.

[0082] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A hollow-core microstructure optical fiber having a positioning surface, characterized in that, It includes a sleeve cladding, a plurality of anti-resonant microstructure units, and a coating; The outer contour of the cross-section of the sleeve cladding is circular; The plurality of anti-resonant microstructure units are distributed inside the sleeve cladding; The coating is coated on the sleeve cladding; The coating has at least one positioning surface such that the outer contour of the cross-section of the hollow microstructure optical fiber is non-circular, and the relative positions of the positioning surface and the plurality of anti-resonant microstructure units are kept consistent in the length direction.

2. The hollow microstructure optical fiber with a positioning surface according to claim 1, characterized in that The positioning surface is a straight line in the cross-section of the hollow microstructure optical fiber.

3. The hollow microstructure optical fiber with a positioning surface according to claim 1 or 2, characterized in that, The coating has a pair of mutually parallel positioning surfaces; or The coating has a plurality of positioning surfaces with a preset included angle.

4. The hollow microstructure optical fiber with a positioning surface according to claim 1 or 2, characterized in that, The outer contour of the cross-section of the coating is D-shaped, racetrack-shaped, quasi-sector-shaped or C-shaped.

5. The hollow microstructure optical fiber with a positioning surface as claimed in claim 1, wherein The coating has a multi-layer structure.

6. The hollow microstructure optical fiber with a positioning surface according to claim 1, characterized in that, The sleeve of the anti-resonant microstructure optical fiber or the inside of the sleeve has a mark, and the mark makes the end face of the hollow microstructure optical fiber have asymmetry.

7. The method for preparing a hollow microstructure optical fiber with a positioning surface according to any one of claims 1 to 5, characterized in that, It includes the following steps: The bare optical fiber of the hollow microstructure optical fiber obtained by wire drawing is coated one or more times through a coating die and cured and formed; The last coating makes the optical fiber pass through a special-shaped coating die in a preset posture, and the cross-section of the coating die has a positioning edge.

8. The preparation method of the hollow microstructure optical fiber with a positioning surface according to claim 6, characterized in that, The coating die has a pair of mutually parallel positioning edges; or The coating die has a plurality of positioning edges with a preset included angle.

9. The manufacturing method of the hollow microstructure optical fiber with a positioning surface as described in claim 6, characterized in that, The cross-section of the coating die is D-shaped, racetrack-shaped, quasi-sector-shaped or C-shaped.

10. The preparation method of the hollow microstructure optical fiber with a positioning surface according to any one of claims 7 or 9, characterized in that The sleeve of the anti-resonant microstructure optical fiber or the inside of the sleeve has a mark, and the mark makes the end face of the hollow microstructure optical fiber have asymmetry; The optical fiber is made to pass through the special-shaped coating die in a preset posture by positioning the mark.

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