Submarine optical cable and manufacturing method thereof

Abstract

The invention relates to a submarine optical cable and a manufacturing method thereof. A plurality of stranded optical units and stranded reinforcers are in contact with the outer surface of a central optical unit and are stranded around the central optical unit to form a cable core; the two stranded reinforcers and the stranded optical unit form an avoiding groove located in the outer surface of the cable core. The outer surface of the stranded optical unit is the groove bottom of the avoiding groove, and the avoiding groove of the cable core indicates that a certain gap exists between the stranded reinforcer and the stranded optical unit, so that the stranded reinforcer provides tensile resistance with certain strength, the optical unit is prevented from being snapped in the stranding production process, in addition, the optical unit is prevented from being directly contacted with a water-blocking tape and a copper pipe in the subsequent production process, and the production efficiency is improved. And the deformation of the optical unit is reduced, so that the production requirements of a water-blocking tape wrapping type submarine cable and a submarine cable with an electric conductor are met. Moreover, the stranding mode of the plurality of stranded optical units and the central optical unit can meet the requirement of placing a plurality of optical fibers in one submarine cable, facilitates the splicing in the subsequent use process, does not damage the spliced optical fibers, and reduces the attenuation.

Description

Technical Field

[0001] The present application relates to the technical field of optical cable manufacturing, and in particular to a submarine optical cable and a manufacturing method thereof. Background Art

[0002] With the development of communication technology, the demand for communication data is increasing, and various communication methods have also been developed accordingly. For transoceanic communication, submarine optical cable communication is still the most widely used. Submarine optical cable communication has the advantages of large transmission capacity, low attenuation, long transmission distance, small size, light weight, no electromagnetic interference, low cost, and long life. It is responsible for the transmission of more than 99% of the world's international data. On the other hand, with the development of optical fiber sensing and special optical fiber, optical fiber with more diversified functions has gradually been used in communication, geological sensing, submarine monitoring and other aspects.

[0003] Traditional submarine optical cables generally use a central tube stainless steel optical unit, with an outer armored steel wire and a copper tube or water-blocking tape covered and then extruded into a PE sheath to provide certain mechanical and insulation protection for the optical unit. One or more layers of steel wire are then armored on the outer layer according to the construction and use environment of the cable. However, due to the size of the optical unit, the number of optical fiber cores can currently only accommodate a maximum of 144 cores, and all optical fibers are placed in an optical unit according to the same process. When the optical unit contains multiple optical fibers, due to the different properties of the optical fibers, the sensitivity to the excess length and bending of the optical fibers is also different. Placing all optical fibers in an optical unit casing to achieve communication, monitoring, experimental testing and other functions will cause optical fiber crosstalk, excessive attenuation, and even fiber breakage.

[0004] Therefore, in order to achieve optimal transmission of optical fiber, it is necessary to lay multiple submarine optical cables, which leads to high laying costs. Therefore, it is necessary to develop a reasonably structured optical unit layer-twisted submarine optical cable to better realize and meet the functions of communication, ocean monitoring, sensing, etc., and reduce manufacturing costs while meeting manufacturing standards. Summary of the invention

[0005] The embodiments of the present application provide a submarine optical cable and a method for manufacturing the same to solve the problem in the related art that different optical fibers are arranged in the same optical unit to achieve communication, monitoring, and experimental testing functions, resulting in easy breakage and deformation during the twisting process of the optical unit.

[0006] In a first aspect, a submarine optical cable is provided, comprising:

[0007] A cable core, comprising a central optical unit, a plurality of twisted optical units and a plurality of twisted reinforcement members; the twisted optical units and the twisted reinforcement members are in contact with the outer surface of the central optical unit and are twisted around the central optical unit;

[0008] Among them, two twisted reinforcement members and one twisted optical unit form an avoidance groove on the outer surface of the cable core; the outer surface of the twisted optical unit is the bottom of the avoidance groove. The main optical unit is used, and the small optical unit is twisted in layers for the production of submarine optical cables to solve the problems of increased crosstalk, increased attenuation, and even fiber breakage between optical fibers due to the mutual influence between optical fibers during the cabling process of multiple optical fibers. One optical unit is turned into multiple optical units that are twisted at the same time, effectively avoiding mutual interference between optical fibers.

[0009] In some embodiments, on the cross-section of the cable core, the centers of all twisted optical units are located on a first circular trajectory; the centers of all twisted strength members are located on a second circular trajectory; the diameter of the second circular trajectory is greater than the diameter of the first circular trajectory; the centers of the first circular trajectory and the second circular trajectory are concentrically arranged with the center of the central optical unit.

[0010] In some embodiments, the optical fiber in the central optical unit includes at least one of a single-core optical fiber, a multi-core optical fiber, a multimode optical fiber, and a grating optical fiber;

[0011] The optical fiber in the twisted optical unit includes at least one of a single-core optical fiber, a multi-core optical fiber, a multi-mode optical fiber, and a grating optical fiber.

[0012] In some embodiments, in the cross section of the cable core, one or more twisted reinforcement members are provided between two adjacent twisted optical units.

[0013] In some embodiments, water-blocking material is filled between the twisted optical units and the twisted reinforcement members, between the central optical unit and the twisted optical units, and between the central optical unit and the twisted reinforcement members;

[0014] The central optical unit comprises a seamlessly welded stainless steel casing, in which a communication optical fiber and a water-blocking fiber paste are arranged.

[0015] In some embodiments, a copper tube, a HDPE sheath, an armor layer and a PP rope wrapping layer are sequentially sheathed radially outside the cable core.

[0016] In some embodiments, an adhesive layer connected to the HDPE sheath is formed by extrusion molding on the outer surface of the copper tube.

[0017] In some embodiments, a water-blocking tape, a HDPE sheath, an armor layer and a PP rope wrapping layer are sequentially wrapped radially on the outer side of the cable core.

[0018] In some embodiments, anti-corrosion asphalt is provided in the gap between the armor layer and the PP rope wrapping layer;

[0019] The armor layer comprises a single layer or two layers of steel wires, and anti-corrosion asphalt is provided in the gaps between the steel wires;

[0020] The PP rope wrapping layer comprises two layers of PP ropes, and anti-corrosion asphalt is arranged in the gap between the PP ropes.

[0021] In a second aspect, a method for manufacturing a submarine optical cable is provided, comprising:

[0022] providing a central optical unit, a plurality of twisted optical units, and a plurality of twisted strength members;

[0023] A plurality of twisted optical units and a plurality of twisted reinforcement members are twisted outside the central optical unit to form a cable core; wherein two twisted reinforcement members and one twisted optical unit form an avoidance groove located on the outer surface of the cable core; and the outer surface of the twisted optical unit is the bottom of the avoidance groove.

[0024] The beneficial effects of the technical solution provided by this application include:

[0025] The embodiment of the present application provides a submarine optical cable and a manufacturing method thereof, because a plurality of twisted optical units and twisted reinforcement members are in contact with the outer surface of the central optical unit, and are twisted around the central optical unit to form a cable core; two twisted reinforcement members and one twisted optical unit form an avoidance groove located on the outer surface of the cable core; the outer surface of the twisted optical unit is the bottom of the avoidance groove, and the avoidance groove of the cable core indicates that there is a certain gap between the twisted reinforcement member and the twisted optical unit, so that the twisted reinforcement member provides a certain strength of tensile resistance, avoiding the optical unit from being broken during the twisting production process, and also avoiding direct contact with the water-blocking tape and the copper tube during the subsequent production process, reducing the deformation of the optical unit, so as to meet the production requirements of the water-blocking tape wrapped submarine cable and the submarine cable with conductor. Furthermore, the twisting method of the above multiple twisted optical units and one central optical unit can meet the requirements of placing multiple optical fibers in a submarine cable, and is also convenient for subsequent splicing during use, without causing damage to the spliced ​​optical fiber, and reducing attenuation. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] 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.

[0027] Figure 1 A schematic diagram of the structure of a cable core provided in an embodiment of the present application, which has a wrapped water-blocking tape and a twisted optical unit that is an overall circular shape;

[0028] Figure 2 A schematic diagram of the structure of a cable core having a copper tube and a twisted optical unit in an incomplete circle provided in an embodiment of the present application;

[0029] Figure 3A schematic diagram of the structure of a cable core with an adhesive layer provided in an embodiment of the present application;

[0030] Figure 4 A schematic diagram of the cross-sectional structure of a submarine optical cable with a copper tube provided in an embodiment of the present application.

[0031] In the figure: 1, central light unit; 2, twisted light unit; 200, first circular track; 3, twisted reinforcement; 300, second circular track; 4, water-blocking material; 5, copper tube; 6, HDPE sheath; 7, armor layer; 8, PP rope wrapping layer; 9, wrapping water-blocking tape; 10, bonding layer; a, avoidance groove. 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] Traditional submarine optical cables generally use a central tube stainless steel optical unit, with an outer armored steel wire and a copper tube or water-blocking tape covered and then extruded into a PE sheath to provide certain mechanical and insulation protection for the optical unit. One or more layers of steel wire are then armored on the outer layer according to the construction and use environment of the cable. However, due to the size of the optical unit, the number of optical fiber cores can currently only accommodate a maximum of 144 cores, and all optical fibers are placed in an optical unit according to the same process. When the optical unit contains multiple optical fibers, due to the different properties of the optical fibers, the sensitivity to the excess length and bending of the optical fibers is also different. Placing all optical fibers in an optical unit casing to achieve communication, monitoring, experimental testing and other functions will cause optical fiber crosstalk, excessive attenuation, and even fiber breakage.

[0034] In addition, all optical fibers are placed into an optical unit according to the same process, and the subsequent connection process will affect the optical fibers, namely deformation and breakage.

[0035] Therefore, in order to achieve optimal transmission of optical fiber, it is necessary to lay multiple submarine optical cables, which leads to high laying costs. Therefore, it is necessary to develop a reasonably structured optical unit layer-twisted submarine optical cable to better realize and meet the functions of communication, ocean monitoring, sensing, etc., and reduce manufacturing costs while meeting manufacturing standards.

[0036] The embodiments of the present application provide a submarine optical cable and a method for manufacturing the same to solve the problem in the related art that different optical fibers are arranged in the same optical unit to achieve communication, monitoring, and experimental testing functions, resulting in easy breakage and deformation during the twisting process of the optical unit.

[0037] In a first aspect, a submarine optical cable comprises:

[0038] The cable core includes a central optical unit 1, a plurality of twisted optical units 2 and a plurality of twisted reinforcement members 3; the twisted optical units 2 and the twisted reinforcement members 3 are both in contact with the outer surface of the central optical unit 1 and are twisted around the central optical unit 1; the diameter of the twisted optical unit 2 is smaller than the diameter of the central optical unit 1.

[0039] Among them, two twisted reinforcement members 3 and one twisted optical unit 2 form an avoidance groove a located on the outer surface of the cable core; the outer surface of the twisted optical unit 2 is the groove bottom of the avoidance groove a.

[0040] The avoidance groove a of the above cable core indicates that there is a certain gap between the twisted reinforcement member 3 and the twisted optical unit 2, so that the twisted reinforcement member 3 provides a certain strength of tensile resistance to avoid the optical unit being pulled apart during the twisting production process. In addition, it also avoids direct contact with the water-blocking tape and the copper tube during the production process, reduces the deformation of the optical unit, and meets the production requirements of water-blocking tape wrapped submarine cables and submarine cables with conductors, reducing attenuation.

[0041] Furthermore, the twisting method of the above multiple twisted optical units 2 and one central optical unit 1 can meet the requirement of placing multiple optical fibers in a submarine cable. Since the multiple optical fibers are arranged separately, it can also reduce the crosstalk of the optical fibers, and is convenient for subsequent splicing during use without causing damage to the spliced ​​optical fibers. The optical unit will not be deformed during the splicing process, thereby reducing attenuation.

[0042] For the avoidance groove a above, there are two specific implementations as follows, which can be understood as the size of the twisted optical unit 2 is slightly smaller than the size of the twisted reinforcement member 3:

[0043] The first one, reference Figure 1 On the cross section of the cable core, the centers of all the twisted optical units 2 are located on the first circular trajectory 200; the centers of all the twisted reinforcement members 3 are located on the second circular trajectory 300; the diameter of the second circular trajectory 300 is larger than the diameter of the first circular trajectory 200; the centers of the first circular trajectory 200 and the second circular trajectory 300 are concentrically arranged with the center of the central optical unit 1.

[0044] In this form, the outer sheath of the twisted optical unit 2 is in an overall circular shape.

[0045] The second one, reference Figure 2 On the cross section of the cable core, the centers of all the twisted optical units 2 and the centers of all the twisted reinforcement members 3 are located on the same circular trajectory, and the center of the circular trajectory is concentrically arranged with the center of the central optical unit 1; the twisted optical unit 2 has a recessed portion or a missing portion relative to the circle to form an avoidance groove a.

[0046] In some preferred embodiments, the optical fiber in the central optical unit 1 includes at least one of a single-core optical fiber, a multi-core optical fiber, a multimode optical fiber, and a grating optical fiber;

[0047] The optical fiber in the twisted optical unit 2 includes at least one of a single-core optical fiber, a multi-core optical fiber, a multi-mode optical fiber, and a grating optical fiber.

[0048] With the above settings, the number of twisted optical units 2 and twisted reinforcement members 3 can be changed according to actual use needs, and the combination of a larger diameter central optical unit 1 + a small diameter twisted optical unit 2 can be used to increase the number of optical fiber cores without increasing the size of the submarine cable, and can be increased to more than 200 cores at most. Multi-core multi-mode optical fiber is applied to the field of submarine communications, and the capacity of a single optical fiber can be increased by dozens of times compared to before. The application of grating optical fiber to the field of submarine communication sensing can realize the sensing measurement of physical quantities such as submarine stress, strain or temperature, and can monitor the status of the submarine cable in real time to ensure the communication quality of the submarine cable. The application of multi-mode OAM strong / weak coupling optical fiber to the field of submarine optical cable communication can realize single-fiber mode division multiplexing and multi-signal transmission, greatly expand the information capacity of optical fiber communication, and also have advantages in submarine scientific experiments.

[0049] It can also be understood that this cable core adopts a main optical unit + N small optical units in the form of layered twisting and is applied to the production of submarine optical cables. It solves the problem of increased crosstalk, increased attenuation, and even fiber breakage between optical fibers due to the mutual influence between optical fibers during the cabling process of multiple optical fibers. One optical unit is turned into multiple optical units and twisted simultaneously, which effectively avoids mutual interference between optical fibers.

[0050] In some preferred embodiments, in order to further reduce optical fiber crosstalk, the following settings are provided:

[0051] On the cross section of the cable core, one or more twisted reinforcement members 3 are arranged between two adjacent twisted optical units 2. The twisted optical units 2 are separated and arranged by using the twisted reinforcement members 3. The twisted reinforcement members 3 are phosphated steel wires.

[0052] In some preferred embodiments, water-blocking material 4 is filled between the twisted optical unit 2 and the twisted reinforcement member 3, between the central optical unit 1 and the twisted optical unit 2, and between the central optical unit 1 and the twisted reinforcement member 3; the water-blocking material 4 plays a role of longitudinal water blocking;

[0053] The central optical unit 1 includes a seamlessly welded stainless steel casing, in which a communication optical fiber and a water-blocking fiber paste are arranged; so that the maximum number of optical fiber cores supported by the central optical unit 1 is 144 cores, and the maximum number of optical fiber cores supported by the twisted optical unit 2 is 20 cores.

[0054] In some preferred implementations, two different submarine cables are provided below based on the above cable core, specifically:

[0055] refer to Figure 4 As shown, the first type of submarine optical cable has a copper tube 5, a HDPE sheath 6, an armor layer 7 and a PP rope wrapping layer 8 radially arranged in sequence on the outer side of the cable core. The copper tube 5 is coated with water-blocking material after being filled, which plays a role in longitudinal water blocking and improving the resistance to crushing. The size of the twisted optical unit 2 is slightly smaller than the size of the twisted reinforcement 3, and there is a certain gap between the two. The twisted reinforcement 3 is used to provide a certain strength of tensile resistance to prevent the optical unit from being broken during the twisting production process. It can not only meet the needs of water-blocking tape wrapped submarine cables, but also copper tubes can be welded on the outside of the cable core to prevent damage to the optical unit after the copper tube is pulled. The copper conductor can be used for power feeding or fault location. A layer of HDPE sheath 6 is extruded outside the cable core, which can not only isolate the internal steel wire and optical unit from corrosion by seawater, but also improve the wear resistance of the submarine optical cable.

[0056] The outer surface of the copper tube 5 is extruded to form an adhesive layer 10 connected to the HDPE sheath 6. The adhesive layer 10 increases the bonding force between the copper tube 5 and the HDPE sheath 6. Figure 3 shown.

[0057] Anti-corrosion asphalt (11) is provided in the gap between the armor layer 7 and the PP rope wrapping layer 8; the armor layer 7 includes a single layer or two layers of steel wires, and the gaps between the steel wires are provided with anti-corrosion asphalt (11); the PP rope wrapping layer 8 includes two layers of PP ropes, and the gaps between the PP ropes are provided with anti-corrosion asphalt (11); the steel wires used in the armor layer 7 formed by the steel wires are single-layer or double-layer galvanized steel wires, which improves the mechanical properties of the submarine cable. The filling material between the gaps between the steel wires in the armor layer is anti-corrosion asphalt (11), and the outer wrapping tape of the steel wire armor layer is a high-strength polypropylene rope, which ensures the round appearance of the submarine cable and improves the wear resistance of the submarine optical cable.

[0058] What should be noted during the manufacturing process is:

[0059] After filling with water-blocking material, the copper strip is coated and then welded and drawn into a copper tube. During the drawing process, the copper strip is embedded in the gap between the steel wire and the optical unit. The diameter of the twisted optical unit 2 is slightly smaller than the diameter of the twisted reinforcement 3. During the copper tube drawing process, the copper tube does not completely contact the optical unit to avoid deformation and breakage of the optical unit. The twisted optical unit 2 can be connected through the optical unit soft joint technology, which solves the limitation that traditional submarine optical cable twisting equipment cannot produce layer-twisted submarine optical cables with a length of more than 30 km, meets the production of long-length submarine optical cables with or without conductors, and realizes the feeding of large-span wet-end equipment or precise fault location.

[0060] After the production of the copper tube cable core is completed, a thin adhesive layer is extruded to increase the bonding strength between the copper tube and HDPE. The thickness is between 0.1-0.5mm according to needs. After the cable core is extruded with the adhesive layer, a layer of HDPE sheath is extruded 6. According to the application scenario and mechanical performance requirements, the sheath thickness is between 2-6mm. The cable core after the sheath is armored with two layers of galvanized steel wire for mechanical protection. The armored submarine optical cable is wrapped with two layers of PP rope, and anti-corrosion asphalt (11) is evenly coated between the cable core and the steel wire and the gap between the PP rope to ensure that the submarine optical cable has a service life of more than 25 years.

[0061] The second type is that the outer side of the cable core is radially covered with a wrapped water blocking tape 9, a HDPE sheath 6, an armor layer 7 and a PP rope wrapping layer 8 in sequence. The gap between the armor layer 7 and the PP rope wrapping layer 8 is provided with anti-corrosion asphalt (11); the armor layer 7 includes a single layer or two layers of steel wires, and the gap between the steel wires is provided with anti-corrosion asphalt (11); the PP rope wrapping layer 8 includes two layers of PP ropes, and the gap between the PP ropes is provided with anti-corrosion asphalt (11).

[0062] During the manufacturing process, it should be noted that: after filling the water-blocking material, the water-blocking tape 9 is formed by wrapping, and the water-blocking tape 9 expands when it encounters water, giving the submarine optical cable excellent longitudinal water-blocking performance, preventing internal water vapor from entering the optical cable and causing hydrogen loss; the diameter of the stranded optical unit 2 is slightly smaller than the diameter of the stranded reinforcement 3, and the two are twisted together, which not only ensures the round appearance, but also avoids the problem of easy breakage and deformation during the twisting process of the optical unit; the stranded optical unit 2 can be connected through the optical unit soft joint technology, solving the limitation that the traditional submarine optical cable twisting equipment cannot produce layer-twisted submarine optical cables of more than 30km;

[0063] After the cable core with the water-blocking tape 9 is finished, a layer of HDPE sheath 6 is extruded. According to the application scenario and mechanical performance requirements, the sheath thickness is between 2-5 mm. The cable core after the sheath is then armored with two layers of galvanized steel wire for mechanical protection. The armored submarine optical cable is wrapped with two layers of PP rope 9, and anti-corrosion asphalt (11) is evenly coated between the cable core and the steel wire and the gap between the PP rope to ensure a service life of more than 25 years for the submarine optical cable.

[0064] In a second aspect, a method for manufacturing a submarine optical cable is provided, comprising:

[0065] Providing a central optical unit 1, a plurality of twisted optical units 2 and a plurality of twisted reinforcement members 3;

[0066] A plurality of twisted optical units 2 and a plurality of twisted reinforcement members 3 are twisted outside the central optical unit 1 to form a cable core; wherein two twisted reinforcement members 3 and one twisted optical unit 2 form an avoidance groove a located on the outer surface of the cable core; and the outer surface of the twisted optical unit 2 is the bottom of the avoidance groove a.

[0067] Subsequently, the above cable cores will be used to manufacture submarine optical cables with or without conductors according to different needs.

[0068] Beneficial effects of this application:

[0069] Without increasing the size of the submarine cable, the use of a stranded submarine cable structure can greatly increase the fiber capacity, with the number of cores reaching more than 200. Reasonable process parameters are customized according to the characteristics of different types of optical fibers, and appropriate excess fiber length and fiber freedom are selected for optical unit production to avoid mutual interference between different types of optical fibers, reduce the manufacturing risk of optical units, and achieve the best communication effect. Placing multiple optical fibers such as single-mode optical fiber, multi-mode OAM optical fiber, multi-core optical fiber, and grating optical fiber in a submarine cable can not only increase single-core communication by dozens of times, but also realize submarine communication, submarine observation and monitoring, underwater sensing, scientific experiments and other functions in one. Different optical fiber functions can achieve the best communication effect, and optical cables with multiple functions can be realized by a single submarine cable, and the manufacturing cost and production risk are reduced. The submarine cable has one or two layers of steel wire armor, which can resist damage from various underwater anchors or wear from reefs, and is suitable for laying, operation, salvage and other operations in complex shallow sea environments.

[0070] In addition, since the twisted optical unit 2 and the twisted reinforcement 3 are in contact with the outer surface of the central optical unit 1 and twisted around the central optical unit 1, the connection difficulty during the production and laying process is small, and it can be used in an environment with a water depth of 0-2000 meters.

[0071] 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.

[0072] 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.

[0073] 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 submarine optical cable, characterized in that: It includes: A cable core, comprising a central optical unit (1), a plurality of twisted optical units (2) and a plurality of twisted reinforcement members (3); the twisted optical units (2) and the twisted reinforcement members (3) are both in contact with the outer surface of the central optical unit (1) and are twisted around the central optical unit (1); Two twisted reinforcement members (3) and a twisted optical unit (2) form an avoidance groove (a) located on the outer surface of the cable core; the outer surface of the twisted optical unit (2) is the bottom of the avoidance groove (a).

2. The submarine optical cable according to claim 1, characterized in that: On the cross section of the cable core, the centers of all the twisted optical units (2) are located on a first circular trajectory (200); the centers of all the twisted reinforcement members (3) are located on a second circular trajectory (300); the diameter of the second circular trajectory (300) is greater than the diameter of the first circular trajectory (200); and the centers of the first circular trajectory (200) and the second circular trajectory (300) are arranged concentrically with the center of the central optical unit (1).

3. The submarine optical cable according to claim 1, characterized in that: The optical fiber in the central optical unit (1) comprises at least one of a single-core optical fiber, a multi-core optical fiber, a multimode optical fiber, and a grating optical fiber; The optical fiber in the twisted optical unit (2) comprises at least one of a single-core optical fiber, a multi-core optical fiber, a multi-mode optical fiber, and a grating optical fiber.

4. The submarine optical cable according to claim 1, characterized in that: On the cross section of the cable core, one or more twisted reinforcement members (3) are arranged between two adjacent twisted optical units (2).

5. The submarine optical cable according to claim 1, characterized in that: The spaces between the twisted optical unit (2) and the twisted reinforcement member (3), between the central optical unit (1) and the twisted optical unit (2), and between the central optical unit (1) and the twisted reinforcement member (3) are all filled with water-blocking material (4); The central optical unit (1) comprises a seamlessly welded stainless steel casing, in which a communication optical fiber and a water-blocking fiber paste are arranged.

6. The submarine optical cable according to claim 5, characterized in that: A copper tube (5), a HDPE sheath (6), an armor layer (7) and a PP rope wrapping layer (8) are sequentially sheathed radially outside the cable core.

7. The submarine optical cable according to claim 6, characterized in that: The outer surface of the copper tube (5) is extruded to form an adhesive layer (10) connected to the HDPE sheath (6).

8. The submarine optical cable according to claim 5, characterized in that: The cable core is radially sheathed in sequence with a wrapped water-blocking tape (9), a HDPE sheath (6), an armor layer (7) and a PP rope wrapped layer (8).

9. The submarine optical cable according to claim 6 or 8, characterized in that: Anti-corrosion asphalt (11) is provided in the gap between the armor layer (7) and the PP rope wrapping layer (8); The armor layer (7) comprises a single layer or two layers of steel wires, and anti-corrosion asphalt (11) is provided in the gaps between the steel wires; The PP rope wrapping layer (8) comprises two layers of PP ropes, and anti-corrosion asphalt (11) is provided in the gap between the PP ropes.

10. A method for manufacturing a submarine optical cable, characterized in that: It includes: Providing a central optical unit (1), a plurality of twisted optical units (2) and a plurality of twisted reinforcement members (3); A plurality of twisted optical units (2) and a plurality of twisted reinforcement members (3) are twisted outside the central optical unit (1) to form a cable core; wherein two twisted reinforcement members (3) and one twisted optical unit (2) form an avoidance groove (a) located on the outer surface of the cable core; and the outer surface of the twisted optical unit (2) is the bottom of the avoidance groove (a).

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