Ultra-low loss hollow-core fiber composite cable based on anti-resonant structure

Abstract

The application relates to the technical field of optical fiber communication cables, in particular to an ultra-low-loss hollow-core optical fiber composite cable based on an anti-resonance structure, which comprises a cylindrical optical fiber composite cable body, a reinforcing rod serving as a support member is arranged at the center of the optical fiber composite cable body, a plurality of spiral partitions fixedly connected with the reinforcing rod are uniformly distributed in the circumferential direction of the reinforcing rod, adjacent spiral partitions form independent spiral cavities, the spiral cavities are variable-pitch spiral channels, hollow-core optical fibers and solid-core optical fibers are arranged in the spiral cavities at intervals and are wound around the outer periphery of the reinforcing rod along the spiral tracks of the spiral partitions, and a sealing protection structure is mounted on the periphery of the spiral cavities, so that the problems in the prior art that the stress resistance is weak, the optical fiber is easily broken or the transmission loss is increased when the optical fiber is laid, stretched and bent, and the crosstalk between the optical fibers is serious, thereby affecting the transmission stability are effectively solved.

Description

An ultra-low loss hollow fiber composite cable based on an anti-resonant structure Technical Field

[0001] This invention relates to the field of optical fiber communication cable technology, and in particular to an ultra-low loss hollow optical fiber composite cable based on an anti-resonance structure. Background Technology

[0002] Anti-resonant hollow fiber is the core carrier of anti-resonant structure. It confines the optical field in the hollow core for transmission through the anti-resonant effect of the capillary array in the cladding, and has the advantages of low loss, high bandwidth and nonlinear resistance.

[0003] One current transmission method uses both hollow-core and solid optical fibers simultaneously. Hollow-core fibers are responsible for handling massive general data throughput, power transmission (through copper-clad wires), and providing monitoring and management channels for the entire system. Hollow-core fibers are responsible for transmitting privileged data that is extremely sensitive to delay, power, or nonlinear effects.

[0004] Existing hollow-core fiber composite cables, which can be used as composite submarine cables, mostly use straight-line fiber optic cable arrangement, which has the following drawbacks: First, the stress resistance is weak, and the fiber is prone to breakage or increased transmission loss when laid under tension or bending. In addition, the straight-line fiber arrangement will also damage the capillary array due to rigid compression when bending, affecting the stability of the anti-resonance condition. Second, the anti-resonance structure is more sensitive to external electromagnetic interference and crosstalk between adjacent fibers. If it is interfered with, it will cause the optical field distribution to be disordered, affecting the transmission stability. Summary of the Invention

[0005] In view of the above situation and to overcome the defects of the prior art, the present invention provides an ultra-low loss hollow fiber composite cable based on an anti-resonant structure, which effectively solves the problems of weak stress resistance, easy fiber breakage or increased transmission loss during laying, tension and bending, and serious crosstalk between fibers, which affect the transmission stability of the prior art.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] An ultra-low loss hollow-core optical fiber composite cable based on an anti-resonance structure includes a cylindrical optical fiber composite cable body. A reinforcing rod serving as a support is disposed at the center of the optical fiber composite cable body. Several spiral spacers, fixedly connected to the reinforcing rod, are evenly distributed around the circumference of the reinforcing rod. Adjacent spiral spacers enclose and form independent spiral chambers. Each spiral chamber is a spiral channel with a variable pitch. Hollow-core optical fibers and solid optical fibers are arranged at intervals within the spiral chambers and wound around the outer circumference of the reinforcing rod along the spiral trajectory of the spiral spacers. A sealing and protective structure is installed around the outer periphery of the spiral chambers. The sealing and protective structure includes an outer sheath, a water-blocking layer, a chamber filling layer, and end seals. The outer sheath is extruded over the outer side of the spiral spacers. The water-blocking layer is disposed between the outer sheath and the spiral spacers. The chamber filling layer fills the gaps between the optical fibers within the spiral chambers. The end seals are disposed at the joints at both ends of the optical fiber composite cable body.

[0008] Preferably, the end seal is provided with a plurality of through holes that correspond to and communicate with the spiral chamber, and a plug is installed in the through hole, with the ends of the hollow optical fiber and the solid optical fiber passing through the plug.

[0009] Preferably, a lead screw is fixedly installed at the end of the reinforcing rod, a rotating handle is threaded onto the lead screw, and a collar is fixedly connected to one end of the rotating handle.

[0010] A positioning pressure plate is rotatably connected inside the collar, and the positioning pressure plate has several positioning grooves that are evenly branched out and correspond to the sealing head.

[0011] Preferably, the sealing head is equipped with a traction shielding wire that is sleeved and installed corresponding to the hollow optical fiber and the solid optical fiber. The traction shielding wire is made of aluminum alloy mesh, which can be bent according to the spiral shape of the channel.

[0012] Preferably, the spiral partition is made of nylon, and the reinforcing rod is made of FRP fiber-reinforced plastic with flexible support capabilities.

[0013] Preferably, the chamber filling layer is made of a biodegradable and waterproof gel material.

[0014] Preferably, the hollow optical fiber is an anti-resonant hollow optical fiber, and the solid optical fiber is a single-mode optical fiber.

[0015] Preferably, the inner diameter of the through hole is larger than the annular diameter of the traction shielding wire.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] 1. The capillary array of anti-resonant hollow fiber must strictly maintain coaxiality and spacing. In this solution, the independent spiral cavity enclosed by the spiral spacer can fix the anti-resonant hollow fiber in the center of the cavity by precisely matching the cavity size with the outer diameter of the fiber and filling the cavity with low modulus waterproof gel, thus avoiding fiber displacement or capillary deformation caused by vibration and stretching during installation.

[0018] 2. Compared to traditional straight spacers, the spiral trajectory of the spiral spacer is adapted to the laying path of the anti-resonant fiber. When bending, the chamber buffers stress through spiral deformation, unlike straight spacers which can damage the capillary array due to rigid compression, ensuring long-term stability of the anti-resonance conditions. The hollow structure of the anti-resonant hollow fiber has poor bending resistance. The spiral spacer in this solution is made of nylon, which can deform synchronously with the cable when bending. At the same time, the spiral chamber makes the fiber spirally wound, and the bending stress is dispersed through the spiral trajectory, avoiding capillary rupture caused by local stress concentration, ensuring the integrity of the anti-resonance structure. The anti-resonant hollow fiber and the solid fiber are arranged in independent spiral chambers, and the spiral spacers between the chambers form a physical barrier, which can prevent scattered light and mode crosstalk during solid fiber transmission from intruding into the anti-resonant fiber and prevent the optical field distribution from becoming disordered.

[0019] 3. A traction shielding line is added to the outside of the anti-resonant hollow fiber and the solid fiber. The traction shielding line is an aluminum alloy mesh used in the spiral channel of the spiral fiber composite cable. It can bend with the spiral shape of the channel and block electromagnetic interference. During maintenance, it can be pulled synchronously with the fiber, which can avoid damage to the hollow fiber and the solid fiber due to being pulled. Attached Figure Description

[0020] Figure 1 is an isometric view of an ultra-low loss hollow fiber composite cable based on an anti-resonance structure according to the present invention.

[0021] Figure 2 is a schematic diagram of the end seal of an ultra-low loss hollow fiber composite cable based on an anti-resonance structure according to the present invention.

[0022] Figure 3 is a schematic diagram of the cavity filling layer of an ultra-low loss hollow optical fiber composite cable based on an anti-resonance structure according to the present invention.

[0023] Figure 4 is a schematic diagram of the reinforcing rod of an ultra-low loss hollow fiber composite cable based on an anti-resonance structure according to the present invention.

[0024] Figure 5 is a schematic diagram of the spiral cavity structure of an ultra-low loss hollow optical fiber composite cable based on an anti-resonance structure according to the present invention.

[0025] Figure 6 is a schematic diagram of the spiral spacer of an ultra-low loss hollow optical fiber composite cable based on an anti-resonance structure according to the present invention.

[0026] Figure 7 is a schematic diagram of the traction shielding wire of an ultra-low loss hollow fiber composite cable based on an anti-resonance structure according to the present invention.

[0027] Figure 8 is a schematic diagram of the sealing head of an ultra-low loss hollow optical fiber composite cable based on an anti-resonance structure according to the present invention.

[0028] Figure 9 is a schematic diagram of the structure of the lead screw of an ultra-low loss hollow optical fiber composite cable based on an anti-resonance structure according to the present invention.

[0029] Figure 10 is a schematic diagram of the collar structure of an ultra-low loss hollow optical fiber composite cable based on an anti-resonance structure according to the present invention.

[0030] In the diagram: 1. Fiber optic composite cable body, 2. End seal, 3. Hollow fiber, 4. Solid fiber, 5. Reinforcing rod, 6. Chamber filling layer, 7. Outer sheath, 8. Water-blocking layer, 9. Spiral spacer, 10. Spiral chamber, 11. Traction shielding wire, 12. Sealing head, 13. Screw, 14. Rotary handle, 15. Positioning pressure plate, 16. Collar, 17. Positioning groove. Detailed Implementation

[0031] As shown in Figures 1-10, an ultra-low loss hollow-core optical fiber composite cable based on an anti-resonance structure includes a cylindrical optical fiber composite cable body 1. A reinforcing rod 5, which serves as a support, is centrally located on the optical fiber composite cable body 1. Several spiral spacers 9, evenly distributed around the reinforcing rod 5 and fixedly connected to it, are uniformly distributed along the circumference of the reinforcing rod 5. Adjacent spiral spacers 9 enclose an independent spiral chamber 10. The spiral chamber 10 is a spiral channel with a variable pitch. Hollow-core optical fibers and solid optical fibers 4 are arranged at intervals within the spiral chamber 10 and wound around the reinforcing rod 5 along the spiral trajectory of the spiral spacers 9. A sealing and protective structure is installed around the spiral chamber 10. The sealing and protective structure includes an outer sheath 7, a water-blocking layer 8, a chamber filling layer 6, and end seals 2. The outer sheath 7 is extruded over the outer side of the spiral spacers 9. The water-blocking layer 8 is disposed between the outer sheath 7 and the spiral spacers 9. The chamber filling layer 6 fills the gaps between the optical fibers within the spiral chamber 10. The end seals 2 are disposed at the joints at both ends of the optical fiber composite cable body 1.

[0032] The end seal 2 is provided with several through holes that correspond to and communicate with the spiral chamber 10. A plug head 12 is installed in the through holes. The ends of the hollow optical fiber and the solid optical fiber 4 pass through the plug head 12. A lead screw 13 is fixedly installed at the end of the reinforcing rod 5. A rotating handle 14 is threaded onto the lead screw 13. A collar 16 is fixedly connected to one end of the rotating handle 14. A positioning pressure plate 15 is rotatably connected inside the collar 16. Several positioning grooves 17 corresponding to the plug head 12 are evenly provided on the branches of the positioning pressure plate 15.

[0033] As shown in Figures 9 and 10, by rotating the handle 14, the handle 14 engages with the screw 13 through a threaded connection, thereby driving the positioning plate 15 inside the collar 16 to move along the axial direction of the screw 13. During the movement, the positioning groove 17 slides along the optical fiber, using the positioning plate 15 to fix the position of the sealing head 12. Since the positioning groove 17 of the positioning plate 15 corresponds one-to-one with the sealing head 12, when the handle 14 is rotated to drive the positioning plate 15 to move axially, the positioning groove 17 can accurately engage the sealing head 12, preventing the sealing head 12 from shifting or loosening, ensuring that the sealing head 12 is tightly fitted to the cable end, improving the reliability of the end sealing, waterproofing, and impurity intrusion prevention. The threaded engagement between the screw 13 and the handle 14 has self-locking properties, and after locking, it is not easy to loosen due to vibration, external force, or other factors. Compared with traditional buckle or binding fixing methods, the fixing strength is higher, and the sealing head 12 can maintain a stable position during long-term use, ensuring that the sealing effect does not diminish.

[0034] The sealing head 12 is equipped with a traction shielding line 11 that is sleeved and installed corresponding to the hollow optical fiber and the solid optical fiber 4. The traction shielding line 11 is made of aluminum alloy mesh, which can be bent according to the spiral shape of the channel.

[0035] As shown in Figures 7 and 8, the traction shielding line 11 has both traction and shielding functions, reducing the risk of damage during maintenance and extending the overall service life of the cable. The electromagnetic shielding function of the traction shielding line 11 for the optical fiber solves the problem of disordered optical field distribution and improves transmission stability.

[0036] The spiral partition 9 is made of nylon, and the reinforcing rod 5 is made of FRP fiber-reinforced plastic with flexible support capabilities.

[0037] As shown in Figure 4, the reinforcing rod 5 is made of FRP fiber-reinforced plastic flexible support material, and the spiral partition 9 is made of nylon tough material. Both have a certain bending deformation capability. The spiral partition 9 itself is spirally extended and naturally has flexibility. When bent, the stress can be dispersed through the spiral trajectory, making it less prone to breakage than the straight partition. The reinforcing rod 5 serves as the central support and can still maintain the core support function after bending.

[0038] The hollow fiber is an anti-resonant hollow fiber, and the solid fiber 4 is a single-mode fiber.

[0039] As shown in Figure 2, the optical field of the anti-resonant hollow fiber is mainly transmitted in the low-loss hollow core, resulting in low transmission loss and extremely weak nonlinear effects. It can carry ultra-high-speed, high-capacity signals and is suitable for high-end transmission requirements such as backbone networks and data center interconnections. Single-mode fiber has mature and stable characteristics: stable transmission performance, strong anti-interference ability, low cost, and mature technology. It can undertake basic communication, signal backup, or control signal transmission tasks, ensuring uninterrupted basic communication outside of core services. The two are arranged at intervals without interference. The physical isolation design of the independent spiral chamber 10 avoids the interference of scattered light from the single-mode fiber with the ultra-high-speed transmission of the anti-resonant hollow fiber. At the same time, the signal from the anti-resonant fiber will not affect the basic transmission of the single-mode fiber, achieving dual protection of high-speed core and stable foundation.

[0040] The chamber filling layer 6 is made of a biodegradable and waterproof gel material.

[0041] The inner diameter of the through hole is larger than the annular diameter of the traction shielding wire 11.

[0042] As shown in Figure 2, during maintenance, a special solvent can be injected into the corresponding spiral chamber 10 through the through hole opened on the end seal 2 to achieve targeted disassembly of the damaged optical fiber without affecting other optical fibers. The special solvent can quickly dissolve the biodegradable waterproof gel in the spiral chamber 10. The damaged optical fiber can be pulled out using the traction shielding wire 11 without violent disassembly. Moreover, no impurities remain after dissolution, and it does not affect refilling.

[0043] The working process of this invention is as follows: Taking the FRP fiber-reinforced plastic reinforcing rod 5 as the center, the nylon spiral spacer 9 is uniformly fixed on its outer periphery to form an independent variable pitch spiral chamber 10. In the spiral chamber 10, anti-resonant hollow optical fibers and single-mode solid optical fibers 4 are arranged at intervals, so that they are wound around the outside of the reinforcing rod 5 along the trajectory of the spiral spacer 9. The gap between the optical fibers in the spiral chamber 10 is filled with biodegradable waterproof gel as the chamber filling layer 6. A water-blocking layer 8 and an outer sheath 7 are arranged in sequence on the outside. End seals 2 are installed at both ends and the ends of the optical fibers are fixed by the sealing head 12.

[0044] An aluminum alloy mesh traction shielding wire 11, sleeved on the optical fiber, is installed at the sealing head 12. The end of the reinforcing rod 5 is fixed by the screw rod 13, the rotating handle 14, and the positioning pressure plate 15. During laying, the spiral chamber 10 is designed as a variable pitch spiral channel. Traditional straight channels are prone to local stress concentration due to rigid structure when bent or stretched, which can lead to optical fiber breakage or capillary array deformation. For different sections of the cable, the variable pitch spiral channel can adjust the pitch density according to the laying environment: a small pitch line section is used in the curved section to extend the actual laying path of the optical fiber, disperse the bending stress, and avoid excessive bending in some areas; in the straight section, the pitch is increased to improve the longitudinal expansion and contraction margin of the channel and offset the direct effect of the tensile force on the optical fiber.

[0045] The chamber filling layer 6 and the water-blocking layer 8 form a double protection, blocking moisture intrusion and fixing the position of the optical fiber to prevent vibration from causing displacement. During operation, the spiral spacer 9 forms a physical barrier to isolate different optical fibers, and the traction shielding line 11 blocks electromagnetic interference and crosstalk, ensuring a stable distribution of the optical field.

[0046] During maintenance, the optical fiber is pulled by the traction shielding wire 11 to avoid damage caused by direct pulling. The positioning pressure plate 15 can quickly calibrate the position of the optical fiber end. The spiral structure disperses bending and tensile stress, avoids local stress concentration in traditional straight-line layout, and solves the problem of easy breakage of optical fiber during laying.

[0047] The flexible support design of the spiral spacer 9 and FRP reinforcing rod 5 is suitable for complex laying environments, reduces the deformation of the capillary array caused by rigid compression, and ensures the stability of anti-resonance conditions.

[0048] The anti-resonant hollow fiber is precisely positioned by the spiral cavity 10 and fixed by the cavity filling layer 6, avoiding the increase in loss caused by vibration displacement and maintaining ultra-low transmission loss characteristics.

[0049] The independently designed septum of the spiral chamber 10 reduces the interference of scattered light between optical fibers. Combined with the electromagnetic shielding function of the traction shielding line 11, it solves the problem of disordered optical field distribution and improves transmission stability.

[0050] The outer sheath 7, water-blocking layer 8, cavity filling layer 6, and end seal 2 form an all-round protection, effectively blocking external erosion such as moisture and dust.

[0051] The biodegradable waterproof gel meets both fixation and environmental protection requirements. The traction shielding wire 11 has dual functions of traction and shielding, reducing the risk of damage during maintenance and extending the overall service life of the cable. The spiral chamber 10 is filled with biodegradable waterproof gel. During maintenance, a special solvent can be injected into the corresponding spiral chamber 10 through the through hole opened on the end seal 2 to achieve targeted disassembly of the damaged optical fiber without affecting other optical fibers. The special solvent can quickly dissolve the biodegradable waterproof gel in the spiral chamber 10. The damaged optical fiber can be pulled out using the traction shielding wire 11 without violent disassembly. After dissolution, no impurities remain and it does not affect refilling.

[0052] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that variations may be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An ultra-low loss hollow-core optical fiber composite cable based on an anti-resonance structure, characterized in that: The cable includes a cylindrical fiber optic composite cable body (1). A reinforcing rod (5) serving as a support is provided at the center of the fiber optic composite cable body (1). Several spiral spacers (9) are evenly distributed around the reinforcing rod (5) and fixedly connected to it. Adjacent spiral spacers (9) enclose an independent spiral chamber (10). The spiral chamber (10) is a spiral channel with a variable pitch. Hollow-core optical fibers (3) and solid optical fibers (4) are arranged at intervals in the spiral chamber (10) and are wound around the reinforcing rod (5) along the spiral trajectory of the spiral spacers (9). A sealing and protective structure is installed around the spiral chamber (10). The sealing and protective structure includes an outer sheath (7), a water-blocking layer (8), a chamber filling layer (6), and an end seal (2). The outer sheath (7) is extruded on the outside of the spiral spacers (9), and the water-blocking layer (8) is disposed between the outer sheath (7) and the spiral spacers (9). Between the spacers (9), the cavity filling layer (6) fills the optical fiber gap in the spiral cavity (10), and the end seal (2) is set at the two ends of the optical fiber composite cable body (1); the end seal (2) is evenly provided with several through holes corresponding to the spiral cavity (10), and the sealing head (12) is installed in the through hole. The ends of the hollow optical fiber (3) and the solid optical fiber (4) are inserted through the sealing head (12); the end of the reinforcing rod (5) is fixedly installed with a screw rod (13), and a rotating handle (14) is threaded on the screw rod (13). One end of the rotating handle (14) is fixedly connected with a collar (16); a positioning pressure plate (15) is rotatably connected in the collar (16), and the positioning pressure plate (15) is evenly provided with several positioning grooves (17) corresponding to the sealing head (12); the cavity filling layer (6) is made of biodegradable waterproof gel material.

2. The ultra-low loss hollow-core optical fiber composite cable based on an anti-resonance structure according to claim 1, characterized in that: The sealing head (12) is equipped with a traction shielding line (11) that is sleeved and installed in accordance with the hollow optical fiber (3) and the solid optical fiber (4). The traction shielding line (11) is made of aluminum alloy mesh, which can be bent according to the spiral shape of the channel.

3. The ultra-low loss hollow-core optical fiber composite cable based on an anti-resonance structure according to claim 1, characterized in that: The spiral partition (9) is made of nylon, and the reinforcing rod (5) is made of FRP fiber-reinforced plastic with flexible support capabilities.

4. The ultra-low loss hollow-core optical fiber composite cable based on an anti-resonance structure according to claim 1, characterized in that: The hollow fiber (3) is an anti-resonant hollow fiber, and the solid fiber (4) is a single-mode fiber.

5. The ultra-low loss hollow-core optical fiber composite cable based on an anti-resonance structure according to claim 1, characterized in that: The inner diameter of the through hole is larger than the annular diameter of the traction shielding wire (11).

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