A submarine optical cable and its manufacturing method

Abstract

This application relates to a submarine optical cable and its manufacturing method. Multiple stranded optical units and stranded reinforcing members 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. Two stranded reinforcing members and one stranded optical unit form a clearance groove on the outer surface of the cable core. The outer surface of the stranded optical unit is the bottom of the clearance groove. This clearance groove in the cable core indicates a certain gap between the stranded reinforcing members and the stranded optical units, providing the stranded reinforcing members with sufficient tensile strength to prevent the optical units from breaking during the stranding process. It also prevents direct contact with water-blocking tape and copper tubing during subsequent production, reducing optical unit deformation and meeting the production requirements of water-blocking tape-wrapped submarine cables and submarine cables with conductive conductors. Furthermore, the stranding method of multiple stranded optical units and one central optical unit can meet the requirement of placing multiple optical fibers in a single submarine cable, facilitating subsequent splicing without damaging the spliced ​​optical fibers and reducing attenuation.

Description

Technical Field

[0001] This application relates to the field of optical cable manufacturing technology, and in particular to a submarine optical cable and its manufacturing method. Background Technology

[0002] With the development of communication technology, the demand for communication data is increasing, and various communication methods have also developed accordingly. For transoceanic communication, submarine optical cable communication is still the most widely used. Submarine optical cable communication boasts advantages such as large transmission capacity, low attenuation, long transmission distance, small size, light weight, no electromagnetic interference, low cost, and long lifespan, undertaking the transmission of over 99% of global international data. On the other hand, with the development of fiber optic sensing and special optical fibers, more versatile optical fibers are gradually being applied in communication, geological sensing, and seabed monitoring.

[0003] Traditional submarine optical cables typically employ a central tube-type stainless steel optical unit, with an outer layer of armored steel wire and a copper tube or water-blocking tape followed by an extruded PE sheath to provide mechanical and insulation protection. Depending on the cable's installation and usage environment, one or more layers of steel wire are then added to the outer armor. However, due to limitations in optical unit size, the maximum number of fiber cores that can be accommodated is currently only 144. Moreover, all optical fibers are placed into a single optical unit using the same process. When an optical unit contains multiple types of optical fibers, the different properties of the fibers result in varying sensitivities to fiber excess length and bending. Placing all optical fibers within a single optical unit sheath to achieve communication, monitoring, and experimental testing functions can lead to crosstalk, excessive attenuation, and even fiber breakage.

[0004] Therefore, in order to achieve optimal transmission of optical fibers, multiple submarine optical cables need to be laid, resulting in high laying costs. Thus, it is necessary to develop a reasonably structured optical unit stranded submarine optical cable to better realize and meet the functions of communication, marine monitoring, and sensing, while reducing manufacturing costs while meeting manufacturing standards. Summary of the Invention

[0005] This application provides a submarine optical cable and its manufacturing method to solve the problem in related technologies where different optical fibers are placed in the same optical unit to realize communication, monitoring and experimental testing functions, which leads to easy breakage and deformation during the twisting process of the optical unit.

[0006] Firstly, a submarine optical cable is provided, which includes:

[0007] The cable core includes a central optical unit, multiple stranded optical units, and multiple stranded reinforcing members; the stranded optical units and stranded reinforcing members are all in contact with the outer surface of the central optical unit and are stranded around the central optical unit;

[0008] In this design, two stranded reinforcing members and one stranded optical unit form a clearance groove on the outer surface of the cable core; the outer surface of the stranded optical unit is the bottom of the clearance groove. This method, employing a main optical unit combined with stranded smaller optical units, is used in the production of submarine optical cables. It addresses the problems of increased crosstalk, attenuation, and even fiber breakage caused by mutual interference between optical fibers during various fiber cabling processes. By transforming a single optical unit into multiple optical units stranded simultaneously, it effectively avoids mutual interference between optical fibers.

[0009] In some embodiments, on the cross-section of the cable core, the centers of all stranded optical units are located on a first circular track; the centers of all stranded reinforcements are located on a second circular track; the diameter of the second circular track is larger than the diameter of the first circular track; and the centers of the first and second circular tracks are concentrically arranged with the center of the central optical unit.

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

[0011] The optical fiber in the stranded optical unit includes at least one of the following: single-core optical fiber, multi-core optical fiber, multimode optical fiber, and grating optical fiber.

[0012] In some embodiments, one or more stranding reinforcements are provided between two adjacent stranded optical units on the cross-section of the cable core.

[0013] In some embodiments, water-blocking material is filled between the stranded optical units and the stranded reinforcing member, between the central optical unit and the stranded optical units, and between the central optical unit and the stranded reinforcing member;

[0014] The central optical unit includes a seamlessly welded stainless steel sleeve, inside which communication optical fibers and water-blocking grease are installed.

[0015] In some embodiments, the outer radial edge of the cable core is sequentially fitted with a copper tube, an HDPE sheath, an armor layer, and a PP rope wrapping layer.

[0016] In some embodiments, an adhesive layer that connects to the HDPE sheath is extruded onto the outer surface of the copper tube.

[0017] In some embodiments, the cable core is radially wrapped with a water-blocking tape, an HDPE sheath, an armor layer, and a PP rope wrapping layer in sequence.

[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 one or two layers of steel wire, with anti-corrosion asphalt provided in the gaps between the steel wires;

[0020] The PP rope wrapping layer consists of two layers of PP rope, with anti-corrosion asphalt in the gap between the PP ropes.

[0021] Secondly, a method for manufacturing a submarine optical cable is provided, comprising:

[0022] It provides a central optical unit, multiple stranded optical units, and multiple stranded reinforcing members;

[0023] Multiple stranded optical units and multiple stranded reinforcing members are stranded around the central optical unit to form a cable core; wherein two stranded reinforcing members and one stranded optical unit form a clearance groove on the outer surface of the cable core; the outer surface of the stranded optical unit is the bottom of the clearance groove.

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

[0025] This application provides a submarine optical cable and its manufacturing method. Multiple stranded optical units and stranded reinforcing members are in contact with the outer surface of the central optical unit and are stranded around the central optical unit to form the cable core. Two stranded reinforcing members and one stranded optical unit form a clearance groove on the outer surface of the cable core. The outer surface of the stranded optical unit is the bottom of the clearance groove. This clearance groove in the cable core indicates a certain gap between the stranded reinforcing members and the stranded optical units, providing the stranded reinforcing members with sufficient tensile strength to prevent the optical units from breaking during the stranding process. It also prevents direct contact with water-blocking tape and copper tubing during subsequent production, reducing optical unit deformation and meeting the production requirements of water-blocking tape-wrapped submarine cables and submarine cables with conductive conductors. Furthermore, the stranding method of multiple stranded optical units and one central optical unit can meet the requirement of placing multiple optical fibers in a single submarine cable, facilitating subsequent splicing without damaging the spliced ​​optical fibers and reducing attenuation. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 A schematic diagram of the structure of a cable core with a wrapping water-blocking tape and a stranded optical unit that is circular, provided for an embodiment of this application;

[0028] Figure 2 A schematic diagram of a cable core with a copper tube and stranded optical units that are not completely circular, provided for an embodiment of this application;

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

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

[0031] In the diagram: 1. Central light unit; 2. Stranded light unit; 200. First circular trajectory; 3. Stranded reinforcement; 300. Second circular trajectory; 4. Water-blocking material; 5. Copper pipe; 6. HDPE sheath; 7. Armor layer; 8. PP rope wrapping layer; 9. Wrapping water-blocking tape; 10. Adhesive layer; a. Clearance groove. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0033] Traditional submarine optical cables typically employ a central tube-type stainless steel optical unit, with an outer layer of armored steel wire and a copper tube or water-blocking tape followed by an extruded PE sheath to provide mechanical and insulation protection. Depending on the cable's installation and usage environment, one or more layers of steel wire are then added to the outer armor. However, due to limitations in optical unit size, the maximum number of fiber cores that can be accommodated is currently only 144. Moreover, all optical fibers are placed into a single optical unit using the same process. When an optical unit contains multiple types of optical fibers, the different properties of the fibers result in varying sensitivities to fiber excess length and bending. Placing all optical fibers within a single optical unit sheath to achieve communication, monitoring, and experimental testing functions can lead to crosstalk, excessive attenuation, and even fiber breakage.

[0034] In addition, all optical fibers are placed into a single optical unit using the same process, which can affect the fibers during subsequent splicing, causing deformation and breakage.

[0035] Therefore, in order to achieve optimal transmission of optical fibers, multiple submarine optical cables need to be laid, resulting in high laying costs. Thus, it is necessary to develop a reasonably structured optical unit stranded submarine optical cable to better realize and meet the functions of communication, marine monitoring, and sensing, while reducing manufacturing costs while meeting manufacturing standards.

[0036] This application provides a submarine optical cable and its manufacturing method to solve the problem in related technologies where different optical fibers are placed in the same optical unit to realize communication, monitoring and experimental testing functions, which leads to easy breakage and deformation during the twisting process of the optical unit.

[0037] Firstly, a submarine optical cable includes:

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

[0039] Among them, two stranded reinforcing members 3 and one stranded optical unit 2 form a clearance groove a on the outer surface of the cable core; the outer surface of the stranded optical unit 2 is the bottom of the clearance groove a.

[0040] The clearance groove 'a' in the above cable core indicates that there is a certain gap between the stranded reinforcement 3 and the stranded optical unit 2, so that the stranded reinforcement 3 provides a certain tensile strength to prevent the optical unit from being pulled apart during the stranding process. In addition, it also avoids direct contact with the water-blocking tape and copper tube during the 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 conductive body, and reduce attenuation.

[0041] Furthermore, the twisting method of the multiple twisted optical units 2 and one central optical unit 1 can meet the requirement of placing multiple optical fibers in a single submarine cable. Since the multiple optical fibers are arranged separately, crosstalk between the optical fibers can be reduced, and it is also convenient for subsequent splicing during use. It will not damage the spliced ​​optical fibers, and the optical units will not deform during the splicing process, thus reducing attenuation.

[0042] Regarding the clearance groove a above, there are two specific implementation methods below, which can be understood as the size of the stranded optical unit 2 being slightly smaller than the size of the stranded reinforcing member 3:

[0043] The first type, reference Figure 1 On the cross-section of the cable core, the center of all stranded optical units 2 is located on the first circular track 200; the center of all stranded reinforcing members 3 is located on the second circular track 300; the diameter of the second circular track 300 is larger than the diameter of the first circular track 200; the center of the first circular track 200 and the second circular track 300 are concentrically set with the center of the central optical unit 1.

[0044] In this form, the outer sheath of the stranded optical unit 2 is a complete circle.

[0045] The second option is to refer to... Figure 2 On the cross-section of the cable core, the center of all stranded optical units 2 and the center of all stranded reinforcing members 3 are located on the same circular track, the center of which is concentric with the center of the central optical unit 1; the stranded optical unit 2 has a recess or a missing part relative to the circle to form a clearance groove a.

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

[0047] The optical fiber in the stranded optical unit 2 includes at least one of the following: single-core optical fiber, multi-core optical fiber, multimode optical fiber, and grating optical fiber.

[0048] With the same setup as above, the number of stranded optical units 2 and stranded reinforcement members 3 can be changed according to actual needs. Using a combination of a larger diameter central optical unit 1 and a smaller diameter stranded optical unit 2 increases the number of fiber cores without increasing the cable size, up to a maximum of over 200 cores. Applying multi-core multimode fiber to submarine communication can increase the capacity of a single fiber by tens of times compared to before. Applying grating fiber to submarine communication sensing enables the sensing and measurement of physical quantities such as seabed stress, strain, or temperature, allowing real-time monitoring of the cable's status and ensuring communication quality. Applying multimode OAM strong / weakly coupled fiber to submarine optical cable communication enables single-fiber mode division multiplexing for multi-signal transmission, significantly expanding the information capacity of optical fiber communication and offering advantages in submarine scientific experiments.

[0049] This can also be understood as the cable core using a main optical unit + N small optical units stranded together in the production of submarine optical cables. This solves the problem of increased crosstalk, increased attenuation, and even fiber breakage caused by mutual interference between optical fibers during the cabling process. It transforms one optical unit into multiple optical units stranded together simultaneously, effectively avoiding mutual interference between optical fibers.

[0050] In some preferred embodiments, the following settings are made to further reduce fiber crosstalk:

[0051] On the cross-section of the cable core, one or more stranding reinforcements 3 are provided between two adjacent stranded optical units 2. The stranded optical units 2 are separated by the stranding reinforcements 3. The stranding reinforcements 3 are made of phosphated steel wire.

[0052] In some preferred embodiments, water-blocking material 4 is filled between the stranded optical unit 2 and the stranded reinforcing member 3, between the central optical unit 1 and the stranded optical unit 2, and between the central optical unit 1 and the stranded reinforcing member 3; the water-blocking material 4 serves to block water longitudinally.

[0053] The central optical unit 1 includes a seamless welded stainless steel sleeve, inside which communication optical fibers and water-blocking grease are installed; thus, the central optical unit 1 can support a maximum number of optical fiber cores of 144 cores, and the stranded optical unit 2 can support a maximum number of optical fiber cores of 20 cores.

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

[0055] refer to Figure 4 As shown, the first type of submarine optical cable has a copper tube 5, an HDPE sheath 6, an armor layer 7, and a PP rope wrapping layer 8 sequentially arranged radially around the outer edge of the cable core. The copper tube 5 is wrapped after being filled with water-blocking material, serving to block water longitudinally and improve resistance to flattening. The stranded optical unit 2 is slightly smaller than the stranded reinforcing member 3, with a certain gap between them. The stranded reinforcing member 3 provides a certain tensile strength, preventing the optical unit from being broken during the stranding process. This not only meets the requirements of water-blocking wrapped submarine cables but also allows for the welding of a copper tube to the outside of the cable core, preventing damage to the optical unit after the copper tube is pulled out. The copper conductor can be used for power supply or fault location. An HDPE sheath 6 is extruded outside the cable core, which not only isolates the internal steel wires and optical units from seawater corrosion but also improves the abrasion resistance of the submarine optical cable.

[0056] An adhesive layer 10, which connects to the HDPE sheath 6, is extruded onto the outer surface of the copper pipe 5. The adhesive layer 10 increases the adhesion between the copper pipe 5 and the HDPE sheath 6. (Reference) Figure 3 As 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 one or two layers of steel wire, and anti-corrosion asphalt (11) is provided in the gap between the steel wires; the PP rope wrapping layer 8 includes two layers of PP rope, and anti-corrosion asphalt (11) is provided in the gap between the PP ropes; the steel wire used in the armor layer 7 formed by the steel wire is a single or double layer of galvanized steel wire, which improves the mechanical properties of the submarine cable. The filling material 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] The following should be noted during the manufacturing process:

[0059] After filling with water-blocking material, copper strip is wrapped 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 stranded optical unit 2 is slightly smaller than the diameter of the stranded reinforcing member 3. During the copper tube drawing process, the copper tube does not come into complete contact with the optical unit to avoid deformation and breakage of the optical unit. The stranded optical unit 2 can be spliced ​​through optical unit soft joint technology, which solves the limitation that traditional submarine optical cable stranding equipment cannot produce stranded submarine optical cables longer than 30km. It meets the production requirements of long-length submarine optical cables with conductors and with or without repeaters, and realizes power supply or precise fault location for long-span wet-end equipment.

[0060] After the copper tube cable core is produced, a thin adhesive layer is extruded to increase the adhesion between the copper tube and HDPE. The thickness is between 0.1-0.5mm as needed. After the adhesive layer is extruded, an HDPE sheath layer is extruded. The sheath thickness is between 2-6mm depending on the application scenario and mechanical performance requirements. The cable core after sheathing 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. Anti-corrosion asphalt (11) is evenly applied between the cable core, steel wire and PP rope gaps to ensure a service life of more than 25 years for the submarine optical cable.

[0061] The second type has a cable core with a water-blocking tape 9, an HDPE sheath 6, an armor layer 7, and a PP rope wrapping layer 8 sequentially arranged radially along its outer edge. 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 one or two layers of steel wire, with anti-corrosion asphalt (11) provided in the gap between the steel wires; the PP rope wrapping layer 8 includes two layers of PP rope, with anti-corrosion asphalt (11) provided in the gap between the PP ropes.

[0062] During the manufacturing process, the following should be noted: After filling with water-blocking material, the water-blocking wrap 9 is formed by wrapping. The water-blocking wrap 9 has the property of expanding when exposed to water, giving the submarine optical cable excellent longitudinal water-blocking performance and 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 reinforcing member 3. The two are stranded together, which not only ensures a round appearance, but also avoids the problems of easy breakage and deformation during the stranding of optical units; the stranded optical unit 2 can be spliced ​​by optical unit soft joint technology, which solves the limitation that traditional submarine optical cable stranding equipment cannot produce stranded submarine optical cables of more than 30km.

[0063] After the cable core with water-blocking tape 9 is produced, an HDPE sheath layer 6 is extruded. The sheath thickness is between 2-5mm depending on the application scenario and mechanical performance requirements. After sheathing, the cable core 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 9. Anti-corrosion asphalt (11) is evenly coated between the cable core, steel wire and PP rope gaps to ensure a service life of more than 25 years for the submarine optical cable.

[0064] Secondly, a method for manufacturing a submarine optical cable is provided, comprising:

[0065] It provides a central optical unit 1, multiple stranded optical units 2, and multiple stranded reinforcing members 3;

[0066] Multiple stranded optical units 2 and multiple stranded reinforcing members 3 are stranded around the central optical unit 1 to form a cable core; wherein two stranded reinforcing members 3 and one stranded optical unit 2 form a clearance groove a located on the outer surface of the cable core; the outer surface of the stranded optical unit 2 is the bottom of the clearance groove a.

[0067] Subsequently, depending on different needs, the above cable cores can be used to manufacture submarine optical cables with and without conductors.

[0068] The beneficial effects of this application are:

[0069] Without increasing the size of the submarine cable, the use of a stranded submarine optical cable structure can significantly increase the fiber capacity, with the number of cores reaching over 200. By customizing reasonable process parameters according to the characteristics of different types of optical fibers, and selecting appropriate fiber excess length and degrees of freedom for optical unit production, interference between dissimilar fibers can be avoided, reducing the manufacturing risk of optical units and achieving the best communication effect. Placing multiple optical fibers, such as single-mode fiber, multi-mode OAM fiber, multi-core fiber, and grating fiber, in a single submarine optical cable not only increases single-core communication by tens of times, but also integrates functions such as submarine communication, submarine observation and monitoring, underwater sensing, and scientific experiments. Different fiber functions achieve optimal communication results, and multiple functions are achieved with a single submarine optical cable, while reducing manufacturing costs and production risks. The submarine cable has one or two layers of steel wire armor, which can resist damage from various underwater anchors or abrasion from reefs, making it suitable for laying, operating, and salvage operations in complex shallow sea environments.

[0070] In addition, since both the stranded optical unit 2 and the stranded reinforcing member 3 are in contact with the outer surface of the central optical unit 1 and are stranded around the central optical unit 1, the splicing difficulty during the production and laying process is small, which meets the requirements for use in environments with water depths of 0-2000 meters.

[0071] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this 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 used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0073] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A submarine optical cable, characterized in that, It includes: The cable core includes a central optical unit (1), multiple stranded optical units (2) and multiple stranded reinforcing members (3); the stranded optical units (2) and stranded reinforcing members (3) are in contact with the outer surface of the central optical unit (1) and are stranded around the central optical unit (1); Among them, two stranded reinforcing members (3) and one stranded optical unit (2) form a clearance groove (a) on the outer surface of the cable core; the outer surface of the stranded optical unit (2) is the bottom of the clearance groove (a); On the cross-section of the cable core, the center of all stranded optical units (2) is located on the first circular track (200); the center of all stranded reinforcing members (3) is located on the second circular track (300); the diameter of the second circular track (300) is larger than the diameter of the first circular track (200); the center of the first circular track (200) and the second circular track (300) are concentrically set with the center of the central optical unit (1); on the cross-section of the cable core, one or more stranded reinforcing members (3) are provided between two adjacent stranded optical units (2).

2. The submarine optical cable as described in claim 1, characterized in that: The optical fiber in the central optical unit (1) includes at least one of the following: single-core optical fiber, multi-core optical fiber, multimode optical fiber, and grating optical fiber; The optical fiber in the stranded optical unit (2) includes at least one of the following: single-core optical fiber, multi-core optical fiber, multimode optical fiber, and grating optical fiber.

3. The submarine optical cable as described in claim 1, characterized in that: Water-blocking material (4) is filled between the stranded optical unit (2) and the stranded reinforcing member (3), between the central optical unit (1) and the stranded optical unit (2), and between the central optical unit (1) and the stranded reinforcing member (3). The central optical unit (1) includes a seamless welded stainless steel sleeve, inside which communication optical fibers and water-blocking grease are provided.

4. The submarine optical cable as described in claim 3, characterized in that: The cable core is radially fitted with a copper tube (5), an HDPE sheath (6), an armor layer (7), and a PP rope wrapping layer (8).

5. The submarine optical cable as described in claim 4, characterized in that: The outer surface of the copper tube (5) is extruded with an adhesive layer (10) that is connected to the HDPE sheath (6).

6. The submarine optical cable as described in claim 3, characterized in that: The cable core is sequentially fitted with a water-blocking wrapping tape (9), an HDPE sheath (6), an armor layer (7), and a PP rope wrapping layer (8) along its outer radial edge.

7. The submarine optical cable as described in claim 4 or 6, 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) includes a single or two layers of steel wire, and anti-corrosion asphalt (11) is provided in the gap between the steel wires. The PP rope wrapping layer (8) includes two layers of PP rope, and anti-corrosion asphalt (11) is provided in the gap between the PP ropes.

8. A method for manufacturing a submarine optical cable as described in claim 1, characterized in that, It includes: Provides a central optical unit (1), multiple stranded optical units (2) and multiple stranded reinforcing members (3); Multiple stranded optical units (2) and multiple stranded reinforcing members (3) are stranded outside the central optical unit (1) to form a cable core; wherein two stranded reinforcing members (3) and one stranded optical unit (2) form a clearance groove (a) located on the outer surface of the cable core; the outer surface of the stranded optical unit (2) is the bottom of the clearance groove (a).

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