Single-core optical cable

Abstract

The invention relates to a single-core optical cable, which comprises a sheath, a reinforcing member, a compression-resistant member, a tight sleeve and an optical fiber, the optical fiber is located at the innermost layer of the single-core optical cable and is tightly wrapped by the tight sleeve, the compression-resistant member is wrapped at the outer side of the tight sleeve, the reinforcing member is wrapped at the outer side of the compression-resistant member, the sheath wraps the reinforcing member, the compression-resistant member, the tight sleeve and the optical fiber, and the optical fiber is wrapped at the outer side of the reinforcing member. At least two continuous W-shaped grooves are formed in the outer surface of the sheath in the length direction of the sheath, and the two W-shaped grooves are distributed in the outer surface of the sheath in a spiral track mode in the longitudinal direction of the optical cable. According to the invention, the torsion resistance, the bending performance and the anti-skid performance of the optical cable are obviously improved, the optical cable is easy to peel, the problems of poor flexibility, easy twisting, difficult peeling and the like of a traditional optical cable are effectively solved, and the environmental adaptability is greatly improved so as to meet diversified application scene requirements.

Description

Technical Field

[0001] The present invention relates to the technical field of optical communication, and particularly to a single-core optical cable. Background Art

[0002] As the core transmission medium of an optical communication system, the sheath structure of an optical cable directly affects the laying efficiency and long-term reliability. Most of the traditional single-core optical cable structures are circular, runway-shaped, or inverted "8"-shaped. Although they have a certain compressive capacity, the circular optical cable structure is prone to slipping and difficult to peel off the outer skin, and the runway-shaped cable laying is prone to twisting and kinking, resulting in fiber breakage.

[0003] In the prior art, there are solutions to improve performance through groove design. For example, the Chinese patent with the publication number CN2849747Y discloses an indoor terminal optical cable for fiber to the home, which includes a sheath, a strengthening member, and a single-core or multi-core tight-buffered optical fiber. The single-core or multi-core tight-buffered optical fiber is arranged in the sheath, two parallel strengthening members are arranged on both sides of the optical fiber, and notches are arranged on the sheath on both sides of the tight-buffered optical fiber. The outer shape of the optical cable is flat, and the notches arranged on the sheath on both sides of the optical fiber are in a "V" shape. By the flat outer shape of the optical cable and the notches arranged on the sheath on both sides close to the tight-buffered optical fiber, the optical fiber is better protected, and at the same time, the peeling performance of the optical cable is improved.

[0004] The above prior art solutions have the following defects: Although special groove treatment is adopted to improve the anti-pressure measurement ability, the structure is single, and the following technical defects are exposed in a complex construction environment: First, the outer surface is smooth, and the friction with the laying equipment is insufficient, so it is easy to slip; second, it is prone to kinking when subjected to external forces, affecting the performance of the internal optical fiber; third, the sheath is difficult to peel off, and additional tools are required and the internal structure is easily damaged. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a single-core optical cable, which has significantly improved anti-twist performance, bending performance, and anti-slip performance, and is easy to peel off, effectively solving the problems of poor flexibility, easy kinking, and difficult peeling of traditional optical cables. At the same time, the environmental adaptability is greatly improved to meet the requirements of diverse application scenarios.

[0006] The above object of the present invention is achieved by the following technical solutions: A single-core optical cable includes a sheath, a strengthening member, a compression-resistant member, a tight jacket, and an optical fiber. The optical fiber is located in the innermost layer of the single-core optical cable and is tightly wrapped by the tight jacket. The compression-resistant member is wrapped outside the tight jacket, the strengthening member is wrapped outside the compression-resistant member, and the sheath wraps the strengthening member, the compression-resistant member, the tight jacket, and the optical fiber. At least two continuous W-shaped grooves are formed on the outer surface of the sheath along its length direction, and the two W-shaped grooves are distributed in a spiral trajectory along the longitudinal direction of the optical cable on the outer surface of the sheath.

[0007] Through the above technical solution, the two continuous W-shaped grooves on the outer surface of the sheath, which are distributed in a spiral trajectory, disperse stress through the spiral structure, avoiding stress concentration at a certain point, thereby effectively improving the torsional resistance of the optical cable, reducing internal structure damage and signal transmission failures caused by torsion. At the same time, the spiral W-shaped grooves can also improve the bending performance, making the optical cable more flexible when bent, buffering the pressure generated by bending to a certain extent, and the W-shaped grooves can also increase the roughness of the outer surface of the sheath, improving the anti-slip performance.

[0008] As a further technical solution of the present invention: the two W-shaped grooves 11 form a left-handed W-shaped groove 11a and a right-handed W-shaped groove 11b with opposite spiral directions and a phase difference of 90°±5°.

[0009] Through the above technical solution, the design of the two W-shaped grooves with opposite spiral directions and a phase difference of 90°±5° causes the two W-shaped grooves to generate reverse bending moments when stressed, offsetting the kinking tendency, and at the same time reducing the local rigidity of the sheath, thereby reducing the minimum bending radius of the optical cable; combined with the buffering effect of the compression-resistant member, significantly improving the anti-kinking ability and flexibility of the optical cable, and suppressing kinking deformation in complex cabling scenarios.

[0010] As a further technical solution of the present invention: the depth of the W-shaped groove is 30%-50% of the thickness of the sheath.

[0011] Through the above technical solution, the precise control of the depth of the W-shaped groove can not only ensure that the existence of the groove can play a role in enhancing torsional resistance, bending, and anti-slip performance, but also will not overly weaken the strength of the sheath, enabling the sheath to continue to provide effective protection for internal components, avoiding the decline of waterproof and moisture-proof performance of the sheath due to too deep grooves, and achieving a balance between various performances.

[0012] As a further technical solution of the present invention: the cross-section of each W-shaped groove is composed of a first V-shaped groove and a second V-shaped groove connected by a middle horizontal plane.

[0013] Through the above technical solution, the W-shaped groove is composed of a first V-shaped groove and a second V-shaped groove connected by a middle horizontal plane. This structure can more precisely disperse the stress generated when the optical cable is subjected to external forces. At the same time, the existence of the middle horizontal plane makes the connection between the two V-shaped grooves more stable, enhancing the structural stability of the W-shaped groove.

[0014] As a further technical solution of the present invention: the angles between both the first outer inclined surface and the first inner inclined surface of the first V-shaped groove and the normal line of the sheath surface are 15°; the angles between both the second outer inclined surface and the second inner inclined surface of the second V-shaped groove and the normal line of the sheath surface are 15°; the first bottom horizontal plane of the first V-shaped groove, the second bottom horizontal plane of the second V-shaped groove, and the middle horizontal plane are all parallel to the optical cable axis.

[0015] Through the above technical solution, the design that the two inclined surfaces of the two V-shaped grooves form an angle of 15° with the normal line of the sheath surface can, when the W-shaped groove bears external forces, disperse the external forces to multiple inclined surfaces, reduce the risk of single-segment overload, play a role in anti-slip and stress dispersion, reduce the risk of local cracking of the sheath, and thus maximize the anti-torsion, anti-compression, and bending performance of the optical cable; and the first bottom horizontal plane, the second bottom horizontal plane, and the middle horizontal plane are all parallel to the optical cable axis, ensuring the stability and symmetry of the groove structure, so that when the optical cable is subjected to external forces, each part can be evenly stressed, avoiding structural deformation and performance degradation caused by uneven stress, and ensuring the stability of the W-shaped groove.

[0016] As a further technical solution of the present invention: the outer surface of the sheath is coated with a silica nanoparticle layer.

[0017] Through the above technical solution, the silica nanoparticle layer can significantly improve the wear resistance of the sheath; the silica nanoparticle layer has good hydrophobicity, can effectively prevent moisture and humidity from entering the inside of the sheath, enhancing the waterproof and anti-slip performance; and the nanoparticle layer can prevent pollutants such as dust and oil from adhering to the surface of the sheath, keep the surface of the optical cable clean, and reduce the risk of performance degradation caused by the accumulation of pollutants.

[0018] As a further technical solution of the present invention: two tearing ropes are arranged at the edges of the W-shaped groove, extending along the spiral trajectories of the left-handed W-shaped groove and the right-handed W-shaped groove respectively, and being embedded in the sheath along the bottom of the middle horizontal plane.

[0019] Through the above technical solution, the tearing ropes extend along the spiral trajectories, and the peeling path is consistent with the spiral direction of the W-shaped groove, avoiding out-of-control tearing and improving the accuracy of peeling. Moreover, the design that the tearing ropes are embedded in the sheath along the bottom of the horizontal plane not only plays a role in guiding the peeling in cooperation with the spiral structure, but also makes the force balanced when peeling the sheath, avoiding the tearing of the sheath caused by stress concentration.

[0020] In summary, the present invention includes at least one of the following beneficial technical effects: 1. The present invention discloses a single-core optical cable. By providing at least two continuous W-shaped grooves in a spiral trajectory on the outer surface of the sheath, and reasonably arranging internal structures such as strengthening members, compression-resistant members, tight sleeves, and optical fibers, the torsional resistance of the optical cable is improved, the torsional stress can be effectively dispersed, and the internal structures can be prevented from being damaged due to torsion; the bending performance is optimized, making the optical cable more flexible and the signal transmission more stable when bent; the anti-slip performance is enhanced, facilitating laying and installation operations; at the same time, each component works together to ensure the stability and reliability of the overall structure of the optical cable, providing a solid guarantee for the efficient transmission of optical signals; 2. The present invention discloses a single-core optical cable. Through the design of two W-shaped grooves with opposite spiral directions and a phase difference of 90° ± 5°, precise control of the groove depth, and the design of the cross-section of the W-shaped groove, the torsional resistance of the optical cable is further enhanced, the stress distribution is more uniform, and at the same time, the strength of the sheath is ensured, achieving a balance between various performances, optimizing the stress dispersion effect, and improving the adaptability and stability of the optical cable under complex external forces; 3. The present invention discloses a single-core optical cable. By coating a silica nanoparticle layer on the outer surface of the sheath, the wear resistance, waterproofness, moisture resistance, and anti-pollution performance of the optical cable are improved, and the service life of the optical cable is extended; 4. The present invention discloses a single-core optical cable. Through the design of a tearing rope, precise peeling of the optical cable is achieved without affecting the structural strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a front view of Embodiment 1 of the present invention.

[0022] Figure 2 is a sectional view of Embodiment 1 of the present invention.

[0023] Reference numerals: 1, sheath; 11, W-shaped groove; 11a, left-handed W-shaped groove; 11b, right-handed W-shaped groove; 101, first V-shaped groove; 101a, first outer inclined surface; 101b, first inner inclined surface; 101c, first bottom horizontal plane; 102, second V-shaped groove; 102a, second outer inclined surface; 102b, second inner inclined surface; 102c, second bottom horizontal plane; 103, middle horizontal plane; 12, tearing rope; 2, strengthening member; 3, compression-resistant member; 4, tight sleeve; 5, optical fiber. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] The following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts belong to the scope of protection of the present application.

[0025] In the description of the present application, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer", "top / bottom end", etc. is based on the orientation or positional relationship shown in the drawings, and is 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 should not be construed as a limitation to the present application. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0026] In the description of the present application, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "provided with", "sheathed / connected", "connected", etc. should be understood in a broad sense. For example, "connected" 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 directly connected or indirectly connected through an intermediate medium, and it can be the communication inside 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 specific circumstances. Embodiment

[0027] Refer to Figure 2 , a single-core optical cable disclosed in the present invention includes a sheath 1, a strengthening member 2, a compressive member 3, a tight sleeve 4, and an optical fiber 5. The optical fiber 5 is located in the innermost layer of the single-core optical cable and is tightly wrapped by the tight sleeve 4. The compressive member 3 is wrapped outside the tight sleeve 4, the strengthening member 2 is wrapped outside the compressive member 3, and the sheath 1 wraps the strengthening member 2, the compressive member 3, the tight sleeve 4, and the optical fiber 5 inside.

[0028] Refer to Figure 1 , at least two continuous W-shaped grooves 11 are formed on the outer surface of the sheath 1 along its length direction, and the two W-shaped grooves 11 are distributed in a spiral trajectory along the longitudinal direction of the optical cable on the outer surface of the sheath 1.

[0029] The two W-shaped grooves 11 form a left-handed W-shaped groove 11a and a right-handed W-shaped groove 11b with opposite spiral directions and a phase difference of 90° ± 5°. The left-handed W-shaped groove 11a rotates counterclockwise along the spiral trajectory on the outer surface of the optical cable, and the right-handed W-shaped groove 11b rotates clockwise along the spiral trajectory on the outer surface of the optical cable.

[0030] Refer to Figure 2, the depth of the W-shaped groove 11 is 30%-50% of the thickness of the sheath 1. The limitation of the depth of the W-shaped groove 11 ensures that the remaining thickness of the sheath 1 can maintain the tensile strength. If the depth of the W-shaped groove 11 is too shallow (<30%), the lateral pressure resistance will be insufficient. If the W-shaped groove 11 is too deep (>50%), the sheath 1 is prone to cracking.

[0031] Reference Figure 2 , the cross-section of each W-shaped groove 11 is composed of a first V-shaped groove 101 and a second V-shaped groove 102 connected by an intermediate horizontal plane 103. The first V-shaped groove 101 and the second V-shaped groove 102 are connected by the intermediate horizontal plane 103 to form a continuous stress transfer path, improving the overall structural stability.

[0032] Reference Figure 2 , the angle between the first outer inclined surface 101a and the first inner inclined surface 101b of the first V-shaped groove 101 and the normal of the sheath 1 surface is 15°. The angle between the second outer inclined surface 102a and the second inner inclined surface 102b of the second V-shaped groove 102 and the normal of the sheath 1 surface is 15°. The 15° angle of the inclined surface can balance the frictional force and the structural strength. If the angle is too small, stress concentration is likely to occur. If it is too large, the anti-slip effect will be weakened.

[0033] The first bottom horizontal plane 101c of the first V-shaped groove 101, the second bottom horizontal plane 102c of the second V-shaped groove 102, and the intermediate horizontal plane 103 are all parallel to the optical cable axis.

[0034] When the optical cable is subjected to external pressure, the structure of the W-shaped groove 11 can evenly disperse the pressure to the intermediate horizontal plane 103 and the horizontal and inclined surfaces of the first V-shaped groove 101 and the second V-shaped groove 102. Compared with the traditional pointed V-shaped groove that only relies on two inclined surfaces to bear the pressure, the W-shaped groove has three more horizontal planes, namely the first bottom horizontal plane 101c, the second bottom horizontal plane 102c, and the intermediate horizontal plane 103, increasing the stress-bearing area and avoiding the situation of excessive local pressure. Thus, the structural stability of the optical cable in a pressurized environment is significantly improved, effectively reducing the risk of sheath deformation or even rupture caused by pressure concentration. When the optical cable encounters torsional force, the spiral trajectory of the W-shaped groove 11 cooperates with its special geometric shape to enhance the anti-torsion ability. For example, the torsional force first acts on each inclined surface, and then through the transfer and redistribution of the first bottom horizontal plane 101c, the second bottom horizontal plane 102c, and the intermediate horizontal plane 103, the stress distribution of the entire sheath 1 in the circumferential direction becomes more uniform, greatly enhancing the anti-torsion ability of the optical cable, preventing internal structural damage caused by excessive torsion, and ensuring the stability of optical signal transmission.

[0035] Meanwhile, during the bending process of the optical cable, the design of the W-shaped groove 11 can effectively reduce the stress at the bending part. When the optical cable bends, the stresses on the inner and outer sides are different, and it is difficult for the traditional V-shaped groove to balance the stresses on the inner and outer sides in this case. However, the first bottom horizontal plane 101c, the second bottom horizontal plane 102c, and the middle horizontal plane 103 of the W-shaped groove 11 can provide additional support and buffering during bending, making the stress distribution at the bending part more reasonable, avoiding excessive stress concentration at a certain point, thereby reducing the possibility of the optical cable breaking or the microbending loss increasing during bending, and ensuring that the optical cable can maintain good performance in frequently bent application scenarios.

[0036] In addition, a silica nanoparticle layer is coated on the outer surface of the sheath 1. The coating process of the silica nanoparticle layer can be achieved by the sol-gel method to realize the chemical bonding between the nanoparticles and the surface of the sheath 1, and the bonding force is ≥5 N / cm to ensure the coating adhesion. The silica nanoparticle layer coated on the outer surface of the sheath 1 can significantly improve the wear resistance of the sheath. During the laying and use of the optical cable, it can reduce the damage to the surface of the sheath caused by friction and extend the service life of the optical cable; the silica nanoparticle layer also has good hydrophobicity, which can effectively prevent moisture and humidity from entering the inside of the sheath, protect the internal optical fiber 5 and other components from the influence of the humid environment, and improve the reliability and stability of the optical cable; at the same time, the nanoparticle layer can prevent pollutants such as dust and oil from adhering to the surface of the sheath 1, keep the surface of the optical cable clean, and reduce the risk of performance degradation caused by the accumulation of pollutants.

[0037] Reference Figure 2 , two tearing ropes 12 are arranged at the edges of the W-shaped groove 11, extending along the spiral tracks of the left-handed W-shaped groove 11a and the right-handed W-shaped groove 11b respectively, and being embedded into the sheath 1 along the bottom of the middle horizontal plane 103. In addition, the starting ends of the tearing ropes 12 are marked, such as using color identification or raised texture marks, to facilitate the accurate positioning of the tearing ropes 12.

[0038] The tearing ropes 12 extend along the spiral tracks of the W-shaped groove 11, fitting the trend of the W-shaped groove 11. When the sheath 1 of the optical cable needs to be peeled off, it can guide the operator to tear the sheath 1 along the accurate path, avoiding problems such as the deviation of the tearing direction of the sheath 1 and the damage to the internal structure caused by random tearing.

[0039] Meanwhile, since the tearing rope 12 is located at the bottom 103 of the middle horizontal plane, which is a position where stress is relatively concentrated and it is convenient to apply force, it can effectively reduce the external force required during peeling, making the peeling operation more labor-saving. Moreover, the tearing rope 12 can first bear and disperse most of the external force, reducing the direct impact of the external force on the internal structures of the optical cable such as the compressive member 3, the tight sleeve 4, and the optical fiber 5, thereby reducing the risk of damage to the internal structure, ensuring the integrity and stability of the internal structure of the optical cable, and further guaranteeing the normal performance of the optical cable.

[0040] The tearing rope 12 extends along a spiral trajectory and is embedded in the bottom of the middle horizontal plane 103, forming good cooperative cooperation with structures such as the W-shaped groove 11 and the strengthening member 2, enhancing the structural synergy. The embedding depth of the tearing rope 12 is controlled within 20% - 30% of the protective sleeve, ensuring that the tearing rope 12 is first damaged during peeling and then the internal structure is contacted.

[0041] The steps for laying the optical cable are as follows: First, conduct a site survey and prepare tools, and prepare the single-core optical cable used for this laying, as well as construction materials and tools such as traction equipment, clamps, and pulleys. Before laying, check the appearance of the optical cable to ensure the integrity of the outer surface of the protective sleeve 1 and the spiral trajectory of the W-shaped groove 11, ensure there are no scratches or defects, and clean the surface of the nano-coating to avoid grease contamination affecting the anti-slip performance.

[0042] Then, set up the traction equipment. Use titanium alloy clamps to hold both ends of the optical cable, and avoid the interface between the compressive member 3 and the tight sleeve 4 for the clamping position. Set the output force of the tractor to 600N (±5%), and monitor the traction force fluctuation in real time through a pressure sensor. If the traction force exceeds 800N, automatically trigger an alarm and suspend construction.

[0043] Next, start the traction setting and drag the optical cable along the preset path. During the laying process, due to the combined action of the W-shaped groove 11 and the silica nanoparticle layer coated on the outer surface of the sheath 1, good anti-slip performance is provided. Arrange a special person to observe. If it is found that the optical cable shows signs of slipping, adjust the traction speed in time or check the ground conditions to ensure smooth laying. In addition, since the two W-shaped grooves 11 form a left-handed W-shaped groove 11a and a right-handed W-shaped groove 11b with opposite spiral directions and a phase difference of 90° ± 5°, the torque can be effectively offset. Pay attention to the torsion situation of the optical cable during construction. If there is an abnormal torsion trend, suspend the traction, adjust the position of the optical cable, and then continue. During the entire traction process, monitor the attenuation change of the optical fiber 5 in real time. When encountering a turning point, guiding pulleys can also be arranged in advance to guide the optical cable to bend smoothly and prevent the bending radius from being too small and affecting the performance of the optical fiber 5.

[0044] After the laying is finally completed, conduct an appearance inspection of the optical cable. Check whether the sheath 1 of the optical cable is worn or scratched, and pay special attention to the positions of the W-shaped groove 11 and the tearing rope 12. If there is any damage, repair it in time; and use professional instruments to test the performance indicators such as the attenuation and bandwidth of the optical fiber 5 to ensure compliance with the relevant standard requirements.

[0045] The steps for stripping the optical cable are as follows: First, locate the starting end of the tearing rope 12. Touch or visually identify the marking points (such as color markings, raised patterns) of the tearing rope 12 along the spiral trajectories of the left-handed W-shaped groove 11a and the right-handed W-shaped groove 11b on the outer surface of the sheath 1 to determine its embedding position at the bottom of the horizontal plane 103.

[0046] Then, strip the sheath in sections at a uniform speed. Use a special stripping tool (such as diagonal pliers or a wire stripper) to cut into the sheath 1 along the spiral trajectory of the tearing rope 12. The cutting depth is controlled within 10%-15% of the total thickness of the sheath 1 to avoid damaging the reinforcement 2 below the middle horizontal plane 103. Guided by the spiral trajectory, tear the sheath 1 in sections. In the left-handed area, apply force by rotating counterclockwise and strip along the trajectory of the left-handed W-shaped groove 11a. In the right-handed area, apply force by rotating clockwise and strip along the trajectory of the right-handed W-shaped groove 11b. When stripping, the direction of the applied force is always consistent with the spiral trajectory direction of the W-shaped groove 11, and the stripping speed is kept uniform.

[0047] Then, strip the reinforcement 2. After the sheath 1 is completely stripped, continue to separate along the interface between the reinforcement 2 and the compressive member 3. Use wire cutters to cut the reinforcement 2 axially and remove its outer layer of metal / composite material.

[0048] Next, isolate the compressive member 3 from the tight jacket 4. Separate along the interface between the compressive member 3 and the tight jacket 4, and gently lift the compressive member 3 using tweezers or a separation tool; retain the connection between the tight jacket 4 and the optical fiber 5 to avoid exposing the optical fiber 5 due to excessive stripping.

[0049] Finally, expose the optical fiber 5 and clean the optical fiber 5. Strip the end of the tight jacket to expose the coating layer of the optical fiber 5, and use anhydrous ethanol (concentration ≥99%) and a lint-free cloth to wipe the surface of the optical fiber 5 along the spiral direction to remove the stripping residues.

[0050] The embodiments of this specific implementation manner are all preferred embodiments of the present invention, and do not limit the protection scope of the present invention accordingly. Therefore: Any equivalent changes made according to the structure, shape, and principle of the present invention shall be covered within the protection scope of the present invention.

Claims

1. A single-core optical cable, comprising a sheath (1), a reinforcing member (2), a pressure-resistant member (3), a tight sleeve (4) and an optical fiber (5), wherein the optical fiber (5) is located in the innermost layer of the single-core optical cable and is tightly covered by the tight sleeve (4), the pressure-resistant member (3) is covered on the outside of the tight sleeve (4), the reinforcing member (2) is covered on the outside of the pressure-resistant member (3), and the sheath (1) wraps the reinforcing member (2), the pressure-resistant member (3), the tight sleeve (4) and the optical fiber (5), characterized in that: The outer surface of the sheath (1) is provided with at least two continuous W-shaped grooves (11) along its length direction, and the two W-shaped grooves (11) are distributed in a spiral track on the outer surface of the sheath (1) along the longitudinal direction of the optical cable.

2. A single-core optical cable according to claim 1, characterized in that: The two W-shaped grooves (11) form a left-handed W-shaped groove (11a) and a right-handed W-shaped groove (11b) with opposite spiral directions and a phase difference of 90°±5°.

3. A single-core optical cable according to claim 1, characterized in that: The depth of the W-shaped groove (11) is 30%-50% of the thickness of the sheath (1).

4. A single-core optical cable according to claim 2, characterized in that: The cross section of each W-shaped groove (11) is composed of a first V-shaped groove (101) and a second V-shaped groove (102) connected by an intermediate horizontal plane (103).

5. A single-core optical cable according to claim 4, characterized in that: The first outer inclined surface (101a) and the first inner inclined surface (101b) of the first V-shaped groove (101) both form an angle of 15° with the surface normal of the sheath (1); The second outer inclined surface (102a) and the second inner inclined surface (102b) of the second V-shaped groove (102) both have an angle of 15° with the surface normal of the sheath (1); The first bottom horizontal plane (101c) of the first V-shaped groove (101), the second bottom horizontal plane (102c) of the second V-shaped groove (102), and the middle horizontal plane (103) are all parallel to the optical cable axis.

6. The single-core optical cable according to claim 1, characterized in that: The outer surface of the sheath (1) is coated with a silicon dioxide nanoparticle layer.

7. A single-core optical cable according to claim 4, characterized in that: Two tear ropes (12) are provided at the edge of the W-shaped groove (11), extending along the spiral tracks of the left-handed W-shaped groove (11a) and the right-handed W-shaped groove (11b), respectively, and embedded in the sheath (1) along the bottom of the middle horizontal plane (103).

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