Multi-core optical fiber structure

Abstract

The utility model relates to the technical field of optical fibers, in particular to a multi-core optical fiber structure, which comprises a multi-core optical fiber body, and the multi-core optical fiber body is sequentially provided with a reinforcing core, a multi-layer core array and a composite sheath from inside to outside. A plurality of isolation groove layers are uniformly embedded among the multiple layers of wire core arrays, the multiple layers of wire core arrays are provided with three groups of inner-layer main cores circularly surrounding the reinforcing core and six groups of outer-layer auxiliary cores arranged around the outer rings of the main cores and distributed in a hexagonal shape, and each isolation groove layer comprises a layer of isolation ring arranged between the inner-layer main cores and the outer-layer auxiliary cores. The isolation grooves are arranged between the adjacent main cores and between the adjacent auxiliary cores and are of a V-shaped structure. According to the structure, a topological optimization and isolation structure mode is adopted, and the overall anti-crosstalk and anti-bending capability is effectively improved.

Description

Technical Field

[0001] This utility model relates to the field of optical fiber technology, specifically a multi-core optical fiber structure. Background Technology

[0002] Multicore fiber is a specially designed fiber structure, characterized by containing multiple independent optical transmission channels (cores) within a single fiber. Compared to traditional single-core fiber, multicore fiber can significantly improve the transmission capacity and density of the fiber, making it suitable for high-bandwidth, high-capacity communication needs.

[0003] In the use of existing multi-core optical fibers, crosstalk and bending loss are prone to occur between the internal optical cores, which affects the normal use of the optical cores. To address this issue, this technical solution designs a core layer topology optimization and isolation structure to solve the above problems. Utility Model Content

[0004] The purpose of this invention is to provide a multi-core optical fiber structure to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] A multi-core optical fiber structure includes a multi-core optical fiber body, which comprises, from the inside out, a reinforcing core, a multi-layer core array, and a composite sheath. Multiple isolation trench layers are uniformly embedded between the multi-layer core arrays. The multi-layer core arrays have three sets of inner main cores arranged in a circle around the reinforcing core and six sets of outer secondary cores arranged in a hexagonal pattern around the outer ring of the main cores. The isolation trench layers include an isolation ring disposed between the inner main cores and the outer secondary cores, and V-shaped isolation trenches disposed between adjacent main cores and adjacent secondary cores.

[0007] Preferably, the isolation trench separates adjacent wire cores through microgrooves filled with fluororesin, achieving a crosstalk suppression ratio of -45dB. The isolation ring is made of fluororesin, forming a ring structure for isolation.

[0008] Preferably, the depth of the isolation trench is set to 1.2-1.5 times the diameter of the corresponding main core or sub-core on both sides.

[0009] Preferably, the reinforcing core is configured as a spiral structure, which is made of carbon fiber filaments and glass fiber filaments spirally twisted together, with a twist pitch of 8-10 times and a twist ratio of 2:1 between carbon fiber filaments and glass fiber filaments.

[0010] Preferably, the composite sheath includes an inner sheath and an outer sheath, with a metal foil shielding layer embedded between the inner and outer sheaths. The inner sheath is made of low-friction polyethylene, and the outer sheath is made of creep-resistant polyamide.

[0011] Compared with the prior art, the beneficial effects of this utility model are: compared with the traditional regular hexagonal arrangement, the double-layer asymmetric structure of this design greatly improves the utilization rate of optical fiber, while reducing the risk of mode field coupling through the differentiated design of the main and auxiliary cores;

[0012] By utilizing V-grooves in conjunction with low-refractive-index materials, crosstalk suppression is improved compared to existing technologies.

[0013] The hybrid structure with spiral reinforcing core maintains flexibility while achieving a tensile strength of 3000N, extending the bending fatigue life compared to a single carbon fiber structure. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of a cross-section of a multi-core optical fiber structure.

[0015] The fiber consists of: a multi-core fiber body 10, a reinforcing core 11, a main core 12, a secondary core 13, an isolation ring 14, an isolation trench 15, an inner sheath 16, an outer sheath 17, and a shielding layer 18. Detailed Implementation

[0016] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0017] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this utility model 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 utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0018] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0019] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0020] Please see Figure 1 A multi-core optical fiber structure includes a multi-core optical fiber body 10, which comprises, from the inside out, a reinforcing core 11, a multi-layer core array, and a composite sheath. Multiple isolation trench layers are uniformly embedded between the multi-layer core arrays to reduce crosstalk between the cores. The multi-layer core arrays include three sets of inner main cores 12 arranged in a circle around the reinforcing core 11 and six sets of outer sub-cores 13 arranged in a hexagonal pattern around the outer ring of the main cores 12, thus achieving an "inner ring, outer hexagon" core layer distribution pattern. The isolation trench layers include an isolation ring 14 disposed between the inner main cores 12 and the outer sub-cores 13, and V-shaped isolation trenches 15 disposed between adjacent main cores 12 and adjacent sub-cores 13, thereby achieving high-density integration and low crosstalk coordination.

[0021] In this embodiment of the invention, the isolation trench 15 separates adjacent wire cores through microgrooves filled with fluororesin, achieving a crosstalk suppression ratio of -45dB. The isolation ring 14 is also made of fluororesin, forming a ring structure for isolation. Fluorine resin possesses properties such as high-frequency signal fidelity, extreme environment tolerance, and self-lubricating characteristics.

[0022] High-frequency signal fidelity: Dielectric constant as low as 2.1 (1MHz), effectively reducing signal transmission loss, suitable for 5G millimeter wave band (24-40GHz).

[0023] Extreme environmental tolerance: Maintains performance under operating conditions of -200~260℃, meeting aerospace-grade standards (ASTM D2 isolation ring 148).

[0024] Self-lubricating properties: friction coefficient 0.05-0.1, reducing cross-linking friction between multi-core wires, ensuring attenuation value ≤0.2dB after 10,000 bends;

[0025] The depth of the isolation trench 15 is set to 1.2-1.5 times the diameter of the corresponding main core 12 or secondary core 13 on both sides;

[0026] The reinforcing core 11 is configured as a spiral structure, which is made of carbon fiber filaments and glass fiber filaments spirally twisted together with a twist pitch of 8-10 times. At the same time, the twisting ratio of carbon fiber filaments and glass fiber filaments is 2:1. This spiral structure can effectively improve the bending resistance of the multi-core optical fiber body 10.

[0027] In one embodiment of the present invention, the composite sheath includes an inner sheath 16 and an outer sheath 17, with a metal foil shielding layer 18 embedded between the inner sheath 16 and the outer sheath 17. Meanwhile, the inner sheath 16 is made of low-friction polyethylene, and the outer sheath 17 is made of creep-resistant polyamide.

[0028] The low-friction polyethylene layer has the following characteristics:

[0029] Dynamic friction coefficient control: After surface modification, the μ value can be reduced to 0.15 (ASTM D shielding 1894), and the wiring tensile strength is reduced by 40% (compared to traditional HDPE).

[0030] Increased microtube fill density: Allows a 0.8 fill ratio within a Φ2mm microtube for an 18-core fiber bundle in the shielding layer;

[0031] Cold flow resistance: Under continuous pressure of 5MPa, deformation <0.5% (-40℃, IEC 60794-1-2).

[0032] Creep-resistant polyamides have the following properties:

[0033] Long-term stress retention: Complies with UL 2261 standard, tensile strength retention after 2000 hours of aging at 80°C >95%;

[0034] Crystal form control technology: Achieving a 3-fold increase in creep resistance index by increasing the β crystal form ratio to >60% (ISO 899-1).

[0035] Layered barrier design: forms a 0.05mm-level interface with the metal layer, and has a hydrogen diffusion coefficient <1 × 10⁻¹ of the multi-core fiber body. 4 cm² / s.

[0036] The metal foil shielding layer 18 has the following characteristics:

[0037] Electromagnetic compatibility performance: The shielding effectiveness of double-layer 45° obliquely wound aluminum foil (12μm thickness) reaches 70dB (1GHz, IEC 61196-1).

[0038] Mechanical-electrical performance synergy: The pleated structure design ensures that the shielding integrity is maintained at >90% when the tensile deformation is 20%;

[0039] Composite shielding structure: Copper / aluminum bimetallic deposition layer (200nm) achieves broadband (DC-40GHz) shielding effectiveness >85dB.

[0040] By combining the above materials, the performance of this optical core in related aspects can be effectively improved.

[0041] In a preferred embodiment of the present invention, during actual manufacturing and use, the reinforcing core 11 can be made of 24 T700 carbon fibers and 12 E glass fibers of the main core twisted in a left-hand spiral (twist pitch 12mm). The main core 12 has a diameter of 9.2μm and a core spacing of 40μm; the secondary core 13 has a diameter of 6.3μm and is arranged in a honeycomb structure. The V-shaped isolation groove 15 has a depth of 15μm and is filled with fluororesin with a refractive index of 1.38. Specifically, in actual measurements at a bending radius of 5mm, the additional loss of the main core 12 is <0.02dB / km, and the inter-core crosstalk is -52dB@10km, thereby effectively improving the anti-crosstalk and bending resistance performance of this optical fiber structure.

[0042] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A multi-core optical fiber structure, characterized by, Including multi-core optical fiber body (10), multi-core optical fiber body (10) are provided with reinforcing core (11), multi-layer core array, composite sheath from inside to outside; Multi-layer core array is uniformly embedded with a plurality of isolation groove layers between, multi-layer core array is provided with three groups of inner layer main core (12) that circularly surround reinforcing core (11) and six groups of outer layer auxiliary core (13) that are distributed in hexagonal type around the outer ring of main core (12), isolation groove layer includes and sets up a layer of isolation ring (14) between inner layer main core (12) and outer layer auxiliary core (13), and the isolation groove (15) of V type structure is set between adjacent main core (12), adjacent auxiliary core (13).

2. A multi-core optical fiber structure according to claim 1, wherein The isolation groove (15) separates adjacent cores by fluororesin filled microgrooves, and the crosstalk suppression ratio reaches-45dB, the isolation ring (14) is made of fluororesin, and forms annular structure for isolation.

3. A multi-core optical fiber structure according to claim 2, wherein The isolation groove (15) is set to 1.2-1.5 times of the diameter of the corresponding two side main core (12) or auxiliary core (13).

4. A multi-core optical fiber structure according to claim 3, wherein The reinforcing core (11) is set to a spiral structure, which is twisted by carbon fiber wire and glass fiber wire, the pitch is 8-10 times, and the twisting ratio of carbon fiber wire and glass fiber wire is 2:

1.

5. A multi-core optical fiber structure according to claim 4, wherein The composite sheath includes inner sheath (16) and outer sheath (17), and a metal foil shielding layer (18) is embedded between the inner sheath (16) and the outer sheath (17), the inner sheath (16) is made of low-friction polyethylene, and the outer sheath (17) is made of anti-cree polyamide.

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