A hollow and solid core fiber hybrid optical cable and a method of manufacturing the same

Abstract

The application discloses a kind of hollow and solid core fiber hybrid optical cable and preparation method thereof, belong to optical cable technical field, hollow and solid core fiber hybrid optical cable includes reinforcing member, and multiple optical units, multiple optical units include the first optical unit with hollow core fiber and the second optical unit with solid core fiber, solid core fiber can be G.652D, G.654E or G.655 etc.;It has accommodating groove on reinforcing member, first optical unit is partially embedded in accommodating groove, the diameter of first optical unit is greater than the diameter of second optical unit, and first optical unit and second optical unit are twisted and arranged in the outer periphery of reinforcing member.The hollow and solid core fiber hybrid optical cable of the application, by simultaneously setting the first optical unit with hollow core fiber and the second optical unit with solid core fiber inside single optical cable, when hollow core fiber is damaged or fails, solid core fiber can be introduced to quickly restore network use, save the detection and connection time of hollow core fiber, and the overall cost of hollow and solid core fiber hybrid optical cable can be reduced.

Description

Technical Field

[0001] This invention belongs to the field of optical cable technology, specifically relating to a hybrid optical cable of hollow and solid optical fibers and its preparation method. Background Technology

[0002] As a next-generation type of optical fiber, hollow fiber is a new type of optical fiber that confines optical signals to air or vacuum for transmission. It has higher transmission rates and power than solid fiber, and has advantages such as low latency, low attenuation and high power. It has broad application prospects in finance, data centers, artificial intelligence, big data and cloud computing.

[0003] While hollow-core optical fiber offers numerous advantages in signal transmission, its complex internal structure, formed by hollow fibers, results in weak bending performance due to structural stress and a larger overall size compared to conventional single-mode fiber. Existing hollow-core optical cables also suffer from a low core count and a limited number of compatible testing and application optical devices. Furthermore, detecting continuity issues and connecting the damaged hollow fiber to relevant equipment is cumbersome, leading to lengthy replacement times, low efficiency, and significant disruption to normal network operation. Summary of the Invention

[0004] In response to one or more of the above-mentioned defects or improvement needs of the existing technology, the present invention provides a hybrid optical cable of hollow and solid optical fibers to solve the problem that the long detection and replacement time of existing hollow optical fibers affects the normal use of the network by users.

[0005] To achieve the above objectives, the present invention provides a hybrid optical cable containing hollow and solid optical fibers, comprising:

[0006] Reinforcing components;

[0007] Multiple optical units, including at least one first optical unit and at least one second optical unit; the first optical unit contains at least one hollow optical fiber, and the second optical unit contains at least one solid optical fiber; the diameter of the first optical unit is larger than the diameter of the second optical unit; the first optical unit and the second optical unit are twisted together on the outer periphery of the reinforcing member.

[0008] The reinforcing member is provided with at least one receiving groove along the axial direction. The extending path of the receiving groove on the surface of the reinforcing member is consistent with the twisting path of the first optical unit. The first optical unit is partially embedded in the receiving groove.

[0009] An outer sheath, which wraps around the outer periphery of the twisted structure of the first optical unit and the second optical unit.

[0010] As a further improvement of the present invention, the non-circularity of the hybrid optical fiber cable containing hollow and solid optical fibers is no greater than 5%.

[0011] As a further improvement of the present invention, the difference between the diameter of the first optical unit and the diameter of the second optical unit is equal to the maximum depth to which the first optical unit is embedded in the receiving groove.

[0012] As a further improvement of the present invention, the inner surface of the receiving groove is a concave arc surface, and the radius of the arc surface of the receiving groove is the same as the radius of the first optical unit, and the first optical unit is attached to the inner wall of the receiving groove.

[0013] As a further improvement of the present invention, the diameter of the first optical unit is L1, the diameter of the second optical unit is L2, and the twisting pitch of the first optical unit and the second optical unit is d;

[0014] The bending radius r1 of the first optical unit is:

[0015] (Formula 7)

[0016] The bending radius r2 of the second optical unit is:

[0017] (Formula 8).

[0018] As a further improvement of the present invention, the duty cycle inside the first optical unit is 5% to 50%.

[0019] As a further improvement of the present invention, the outer periphery of the twisted structure of the first optical unit and the second optical unit is wrapped with binding yarn.

[0020] As a further improvement of the present invention, the first optical unit and the second optical unit are intermittently bonded to the outer wall of the reinforcing member along the axial direction by adhesive.

[0021] As a further improvement of the present invention, the number of fiber cores in the first optical unit is the same as the number of fiber cores in the second optical unit;

[0022] The hollow fiber is an anti-resonant hollow fiber, and the solid fiber is a single-mode fiber or a multimode fiber.

[0023] As a further improvement of the present invention, it also includes at least one filler rope, which is twisted together with the first optical unit and the second optical unit and disposed on the outer periphery of the reinforcing member.

[0024] This invention also includes a method for preparing a hybrid optical cable of hollow and solid optical fibers, comprising the following steps:

[0025] A reinforcing member is obtained, wherein a receiving groove is formed on the outer periphery of the reinforcing member;

[0026] A traction reinforcement member is provided, wherein the first optical unit and the second optical unit are twisted together and disposed on the outer periphery of the reinforcement member, and the first optical unit is embedded in the receiving groove;

[0027] An outer sheath is extruded around the first optical unit and the second optical unit.

[0028] The aforementioned improved technical features can be combined with each other as long as they do not conflict with each other.

[0029] In summary, the beneficial effects of the above-described technical solutions conceived by this invention compared with the prior art include:

[0030] (1) The hybrid optical cable of hollow and solid optical fibers of the present invention, by simultaneously setting a first optical unit with hollow optical fibers and a second optical unit with solid optical fibers inside a single optical cable, can quickly restore network use when the hollow optical fibers are damaged or malfunctioning by introducing solid optical fibers, saving the detection and connection time of the hollow optical fibers. Moreover, the hybrid optical cable of hollow and solid optical fibers can reduce the overall cost of the hollow optical cable and reduce the manufacturing cost of the optical cable. At the same time, by opening a receiving groove on the reinforcing member and placing the first optical unit in the receiving groove, the first optical unit containing the hollow optical fibers is closer to the center of the reinforcing member. When the first optical unit and the second optical unit are stranded, under the same stranding pitch, the first optical unit has a larger stranding bending radius along the reinforcing member, and the bending stress on the hollow optical fibers inside is smaller, reducing the probability of damage to the hollow optical fibers.

[0031] (2) The hybrid optical cable of hollow and solid optical fibers of the present invention, by setting the inner surface of the receiving groove as a concave arc surface structure, and the radius of the arc surface of the receiving groove is the same as the radius of the first optical unit, so that the outer wall of the first optical unit is tightly attached to the inner wall of the receiving groove, and the receiving groove and the first optical unit are tightly attached, thus avoiding the pressure of the groove opening on the first optical unit. In addition, the way in which the first optical unit contacts the reinforcing member increases the contact area between the first optical unit and the reinforcing member. Compared with the line contact between the second optical unit and the reinforcing member, the reinforcing member can provide greater friction for the first optical unit, which can alleviate the shrinkage problem of the first optical unit, facilitate the control of the excess length of the hollow optical fiber and the sleeve of the first optical unit, and avoid the hollow optical fiber bending inside the sleeve due to excessive shrinkage of the sleeve, which increases the bending loss of the hollow optical fiber. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the overall structure of a hybrid optical cable containing hollow and solid optical fibers according to an embodiment of the present invention;

[0033] Figure 2 This is a schematic diagram of the overall structure of another hybrid optical cable with hollow and solid optical fibers in an embodiment of the present invention;

[0034] Figure 3This is a schematic diagram of the reinforcing member structure in an embodiment of the present invention.

[0035] In all the accompanying drawings, the same reference numerals denote the same technical features, specifically:

[0036] 1. Reinforcing member; 2. First optical unit; 3. Second optical unit; 4. Receiving slot; 5. Outer sheath; 6. Tube; 7. Hollow optical fiber; 8. Solid optical fiber; 9. Filler rope. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0038] In the description of this invention, it should be understood that, unless otherwise stated, the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0039] Furthermore, unless otherwise stated, the terms "first" and "second" 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, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0040] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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 of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0041] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0042] Example:

[0043] Please see Figure 1 The hybrid optical cable of hollow and solid optical fibers in a preferred embodiment of the present invention includes a reinforcing member 1; and a plurality of optical units, including at least one first optical unit 2 and at least one second optical unit 3; wherein the first optical unit 2 contains at least one hollow optical fiber 7, and the second optical unit 3 contains at least one solid optical fiber 8, and the diameter of the first optical unit 2 is larger than the diameter of the second optical unit 3; the first optical unit 2 and the second optical unit 3 are twisted together on the outer periphery of the reinforcing member 1. Simultaneously, the reinforcing member 1 has at least one receiving groove 4 along the axial direction, the extension path of the receiving groove 4 on the surface of the reinforcing member 1 being consistent with the twisting path of the first optical unit 2, and the first optical unit 2 is partially embedded in the receiving groove 4; and an outer sheath 5, which wraps around the outer periphery of the twisted structure of the first optical unit 2 and the second optical unit 3.

[0044] Specifically, the present invention uses a hybrid optical cable formed by mixing hollow-core optical fibers and solid-core optical fibers. The solid-core optical fibers can be G.652D, G.654E, or G.655, etc. By simultaneously arranging a first optical unit 2 containing hollow-core optical fibers 7 and a second optical unit 3 containing solid-core optical fibers 8 within a single optical cable, when the hollow-core optical fiber 7 is damaged or malfunctions, the network can be quickly restored by introducing the solid-core optical fiber 8, saving the detection and connection time of the hollow-core optical fiber 7. At the same time, the hybrid optical cable of hollow and solid fibers can reduce the overall cost of the hollow-core optical cable and lower the manufacturing cost. Furthermore, based on the hybrid structure of hollow-core optical fibers 7 and solid-core optical fibers 8, since the hollow-core optical fiber 7 itself has a complex structure and is sensitive to stress, using the same cable standard as the solid-core optical fiber 8 would lead to damage to the hollow-core optical fiber 7, rendering it unusable. The present invention provides a method for placing the first optical unit 2 in a receiving groove 4 on the reinforcing member 1. This method allows the first optical unit 2, which contains the hollow optical fiber 7, to be closer to the center of the reinforcing member 1. When the first optical unit 2 and the second optical unit 3 are stranded, the first optical unit 2 has a larger bending radius along the reinforcing member 1 at the same stranding pitch, and the hollow optical fiber 7 inside it experiences less bending stress, thereby reducing the probability of the hollow optical fiber 7 being damaged by bending.

[0045] Furthermore, as an optional embodiment of the present invention, the non-circularity of the hybrid optical cable of hollow and solid optical fibers is no greater than 5%. Since the diameter of the first optical unit 2 is larger than the diameter of the second optical unit 3, even if the first optical unit 2 is partially embedded in the receiving groove 4, it is difficult to ensure that the outer edges of all the first optical units 2 and all the second optical units 3 are on the same arc surface. This will cause the sheath material to shrink inwards during the extrusion of the outer sheath 5, resulting in an overall non-circular optical cable. Excessive non-circularity of the optical cable will lead to difficulty in controlling the excess fiber length, micro-bending loss, and unstable mechanical properties. Therefore, the non-circularity of the hybrid optical cable of hollow and solid optical fibers in the present invention is no greater than 5%. This is achieved by controlling the amount of sheath material extruded or adjusting the diameters of the first optical unit 2 and the second optical unit 3, so that the outer edges of the first optical unit 2 and the second optical unit 3 are approximately circular, ensuring the normal forming and stable use of the hybrid optical cable of hollow and solid optical fibers. Specifically, in this invention, non-circularity refers to the standard of how much the cross-section of an optical cable deviates from the ideal circle. It refers to the percentage value obtained by dividing the difference between the maximum and minimum diameters on the same cross-section of the optical cable by the average diameter of that cross-section and then multiplying by 100%. For details, please refer to the specific description of non-circularity in the optical fiber geometric parameters of GB / T 7424.20-2021 and GB / T 15972.20-2021.

[0046] Furthermore, as an optional embodiment of the present invention, the difference between the diameter of the first optical unit 2 and the diameter of the second optical unit 3 is equal to the maximum depth to which the first optical unit 2 is embedded in the receiving groove 4. To ensure that the hybrid optical cable of hollow and solid fibers is integrally formed into a regular circular cable structure, the maximum depth of the receiving groove 4, the diameter of the first optical unit 2, and the diameter of the second optical unit 3 can be adjusted to compensate for the portion of the length of the first optical unit 2 within the receiving groove 4. This results in the outer edges of the first optical unit 2 and the second optical unit 3 forming a basically circular structure, allowing for regular extrusion forming around the outer periphery of the optical unit during subsequent extrusion of the outer sheath 5. This avoids problems such as dents in the formed outer sheath 5 or material accumulation during extrusion due to irregularities inside the outer sheath 5. Increasing the diameter of the first optical unit 2 also increases the internal space, making the internal occupancy of the first optical unit 2 higher than that of the second optical unit 3. This provides more space for the hollow optical fiber 7 to move, reducing the impact of external bending stress on the hollow optical fiber 7 and further reducing the probability of damage to the hollow optical fiber 7 during construction.

[0047] In addition, since existing hollow fiber optic cable testing and usage equipment is not widespread, the existing equipment may not be compatible with hollow fiber 7. The hybrid optical cable of hollow and solid fiber in this invention can first provide network services through solid fiber 8, and hollow fiber 7 can be temporarily laid in the network pipeline. When the related equipment and services of hollow fiber 7 become widespread, hollow fiber 7 can replace solid fiber 8, thereby improving network transmission efficiency and power, eliminating the need to lay additional hollow fiber optic cable and saving pipeline resources.

[0048] Furthermore, as an optional embodiment of the present invention, the inner surface of the receiving groove 4 is a concave arc surface, and the radius of the arc surface of the receiving groove 4 is the same as the radius of the first optical unit 2. The first optical unit 2 is attached to the inner wall of the receiving groove 4. By setting the receiving groove 4 on the reinforcing member 1, the outer edges of the first optical unit 2 and the second optical unit 3 can form a basically circular structure. However, the receiving groove 4 itself may squeeze the outer wall of the first optical unit 2. When the hollow and solid optical fiber hybrid cable is bent or compressed, the receiving groove 4 and the external force squeeze the first optical unit 2 together, which will compress the internal space of the first optical unit 2 and affect the normal use of the hollow optical fiber 7. Therefore, the inner surface of the receiving groove 4 can be set as a concave arc surface structure, and the radius of the arc surface of the receiving groove 4 is the same as the radius of the first optical unit 2, so that the outer wall of the first optical unit 2 is tightly attached to the inner wall of the receiving groove 4. The form of the receiving groove 4 and the first optical unit 2 being tightly attached avoids the groove opening of the receiving groove 4 from compressing the first optical unit 2. In addition, the surface contact between the first optical unit 2 and the reinforcing member 1 can increase the contact area between the first optical unit 2 and the reinforcing member 1. Compared with the line contact between the second optical unit 3 and the reinforcing member 1, the reinforcing member 1 can provide the first optical unit 2 with greater friction, which can alleviate the shrinkage problem of the first optical unit 2, facilitate the control of the excess length of the hollow optical fiber 7 and the sleeve 6 of the first optical unit 2, and avoid the hollow optical fiber 7 bending inside the sleeve 6 due to excessive shrinkage of the sleeve 6, which would increase the bending loss of the hollow optical fiber 7.

[0049] Furthermore, as an optional embodiment of the present invention, the diameter of the first optical unit 2 is set to L1, the diameter of the second optical unit 3 is set to L2, the diameter of the reinforcing member 1 is set to L3, and the twisting pitch of the first optical unit 2 and the second optical unit 3 is both d, such as... Figure 3 As shown. It is worth noting that when the first optical unit 2 is twisted onto the surface of the reinforcing member 1, the actual bending radius of the first optical unit 2 is the bending radius of the first optical unit 2 toward the inner side of the center of the reinforcing member 1. The bending radius r1 of the first optical unit 2 in the figure is only for reference.

[0050] The diameters of the first optical unit 2, the second optical unit 3, and the twisting pitch of the first optical unit 2 satisfy the following relationship:

[0051] (Formula 1)

[0052] Specifically, the twisting radius R1 of the first optical unit 2 is:

[0053] R1 = (2L1 + L2 - L3) / 2 (Formula 2)

[0054] The twisting radius R2 of the second optical unit 3 is:

[0055] R2 = (L2 + L3) / 2 (Formula 3)

[0056] Based on the twisting radius of the first optical unit 2 and the second optical unit 3, the bending radius r1 of the first optical unit 2 can be obtained as follows:

[0057] (Formula 4)

[0058] The bending radius r2 of the second optical unit 3 is:

[0059] (Formula 5)

[0060] When conventional solid-core single-mode optical fibers are stranded in an optical cable, the minimum bending radius r2 of the sleeve 6 is 30mm, and when hollow-core optical fibers 7 are stranded in an optical cable, the minimum bending radius r1 of the sleeve 6 is approximately 50mm. The hybrid optical cable of hollow and solid fibers in this invention satisfies the bending radii of both solid-core optical fibers 8 and hollow-core optical fibers 7, as set as follows:

[0061] r1>r2 (Formula 6)

[0062] Preferably, the bending radius r1 of the first optical unit 2 is not less than 50 mm, and the bending radius r2 of the second optical unit 3 is not less than 30 mm. During the design process, the hollow fiber 7 is designed with a length of 0 mm. Ideally, the hollow fiber 7 is located in the central region of the sleeve 6. Therefore, the bending radius of the first optical unit 2 is the same as the bending radius of the hollow fiber 7. Here, the solid fiber 8 is treated in the same way as the hollow fiber 7. Therefore, the bending radii of the first optical unit 2 and the second optical unit 3 are equivalent to the bending radii of the hollow fiber 7 and the solid fiber 8. Based on the minimum bending radius limitation of the hollow fiber 7 and the solid fiber 8, the dimensional relationships of the first optical unit 2, the second optical unit 3, the reinforcing member 1, and the stranding pitch during the manufacturing process can be calculated to guide the manufacturing parameters of the hybrid optical cable of hollow and solid fibers.

[0063] Substituting formulas 2 and 3 into formulas 4 and 5, we get:

[0064] (Formula 7)

[0065] (Formula 8)

[0066] Finally, substituting equations 7 and 8 into equation 6, we obtain the relevant equations for L1, L2, L3, and d:

[0067] (Formula 1)

[0068] Furthermore, as an optional embodiment of the present invention, the duty cycle inside the first optical unit 2 is 5% to 50%. Specifically, the duty cycle here refers to the ratio of the total cross-sectional area of ​​all hollow optical fibers 7 in the first optical unit 2 to the cross-sectional area of ​​the inner cavity of the sleeve 6 of the first optical unit 2.

[0069] Furthermore, as an optional embodiment of the present invention, the number of fiber cores in the first optical unit 2 and the number of fiber cores in the second optical unit 3 are the same. Based on the application scenario of the hybrid hollow and solid fiber optical cable of the present invention, there is a scheme where solid fiber 8 is used initially to provide network support, and hollow fiber 7 is used to replace solid fiber 8 subsequently. Therefore, setting the first optical unit 2 and the second optical unit 3 to have the same number of cores ensures that the communication needs of all devices can be met during subsequent replacements.

[0070] Furthermore, as an optional embodiment of the present invention, the outer periphery of the twisted structure of the first optical unit 2 and the second optical unit 3 is wrapped with binding yarn. The first optical unit 2 and the second optical unit 3 are twisted and disposed on the outer periphery of the reinforcing member 1. Without external constraints, a twisting problem may occur. In order to ensure the overall bending performance of the hybrid optical cable of hollow and solid optical fibers, the twisting problem of the optical units should be avoided as much as possible. Therefore, the first optical unit 2 and the second optical unit 3 can be fixed to the outer periphery of the reinforcing member 1 by binding yarn. In addition, the binding yarn method can bind the twisted structure of the first optical unit 2 and the second optical unit 3 into an approximately circular shape, avoiding the gap between the first optical unit 2 and the second optical unit 3 from being exposed, and preventing the outer sheath 5 from shrinking inward when the sheath material fills the gap between the first optical unit 2 and the second optical unit 3 during the extrusion molding of the outer sheath 5.

[0071] Furthermore, as an optional embodiment of the present invention, the first optical unit 2 and the second optical unit 3 are intermittently bonded to the outer wall of the reinforcing member 1 along the axial direction using adhesive. Besides fixing the stranded structure of the first optical unit 2 and the second optical unit 3 using a yarn-tying method, the first optical unit 2 and the second optical unit 3 can also be adhered to the reinforcing member 1 by adhesive curing. To ensure the subsequent branching and extraction of optical fibers, the first optical unit 2 and the second optical unit 3 are intermittently bonded along the axial direction of the reinforcing member 1, reducing the amount of adhesive used and facilitating the separation of the optical units from the reinforcing member 1. In addition, the adhesive bonding method between the first optical unit 2 and the second optical unit 3 and the reinforcing member 1 can further mitigate the shrinkage problem of the optical unit sheath, facilitating the control of the excess length of the first optical unit 2 and the second optical unit 3 during shrinkage.

[0072] It is worth noting that when the first light unit 2 and the second light unit 3 are bonded to the reinforcing member 1 with glue, there is a gap between the first light unit 2 and the second light unit 3. In order to avoid the gap affecting the molding of the outer sheath 5, the outer sheath 5 can be molded by vacuum sizing process.

[0073] Furthermore, as an optional embodiment of the present invention, the hollow fiber 7 is an anti-resonant hollow fiber, and the solid fiber 8 is a single-mode fiber or a multimode fiber. The anti-resonant hollow fiber is a subcategory of the hollow fiber 7, and it has advantages such as simple processing and strong structural stability. Single-mode and multimode fibers are subcategories of the solid fiber 8. In this invention, the hybrid optical cable of hollow and solid fibers does not restrict the solid fiber 8; appropriate types of fibers can be selected according to requirements.

[0074] More preferably, the solid fiber 8 is a single-mode fiber, and the single-mode fiber model is G652D, G654E, G655, G657A, etc.

[0075] More preferably, the arrangement of the optical fibers inside the second optical unit 3 in this invention is not limited, and can be ribbon optical fibers, flexible optical fiber ribbons, or loosely arranged optical fibers.

[0076] Furthermore, as an optional embodiment of the present invention, the reinforcing member 1 in the present invention is FRP, single-strand steel wire, or stranded steel wire. When stranded steel wire is used, part of the structure of the stranded steel wire needs to be removed to form a receiving groove 4 on the outer periphery of the reinforcing member 1 that is compatible with the stranded structure of the first optical unit 2, and at this time the stranding method of the first optical unit 2 is S-twisted or Z-twisted.

[0077] In addition, the reinforcing member 1 is preferably a plastic-molded reinforcing member. When the reinforcing member 1 is plastic-molded, the shape of the plastic-molded structure is processed by rotating the mold cover so as to form the receiving groove 4 on the outer periphery of the reinforcing member 1, thus eliminating the problem that the conventional reinforcing member 1 needs to be processed twice to form the receiving groove 4.

[0078] Optionally, in this invention, the first optical unit 2 and the second optical unit 3 are SZ twisted or S twisted.

[0079] Optionally, there are multiple first optical units 2 in this invention, and multiple receiving grooves 4 are formed on the outer periphery of the reinforcing member 1, with each receiving groove 4 corresponding to one of the multiple first optical units 2.

[0080] Preferably, in this invention, both the first optical unit 2 and the second optical unit 3 have a sleeve 6, and both the solid optical fiber 8 and the hollow optical fiber 7 are disposed inside the sleeve 6. A water-blocking material is filled between the sleeve 6 and the solid optical fiber 8 / hollow optical fiber 7. The water-blocking material can be water-blocking powder, water-blocking yarn, or water-blocking paste. Preferably, the sleeve 6 of the first optical unit 2 and the second optical unit 3 is a loose sleeve.

[0081] Furthermore, such as Figure 2As shown, as an optional embodiment of the present invention, the hybrid optical cable of hollow and solid optical fibers further includes at least one filler rope 9, which is twisted together with the first optical unit 2 and the second optical unit 3 and disposed on the outer periphery of the reinforcing member 1. During optical cable manufacturing, the customer may not require an excessively high number of fiber cores. In areas with low population density, an excessively high number of fiber cores in the optical cable would result in fiber waste. To ensure proper optical cable formation, the filler rope 9 can be used to replace some optical units, thereby saving on optical cable manufacturing costs.

[0082] Optionally, the outer sheath 5 and the sleeve 6 of the optical unit in this invention are similar to conventional optical cables. The outer sheath 5 is usually made of polyethylene, polypropylene or polyvinyl chloride. High-strength, flame-retardant, UV-resistant and low-friction outer sheaths can be made based on specific needs, which will not be elaborated here. The sleeve 6 is made of polyethylene, polypropylene or polyamide materials. Depending on the usage requirements, it can also be made of polyetheretherketone, polyamide or other materials, or the material can be modified to prepare a sheath structure for a specific scenario.

[0083] Furthermore, the present invention also includes a method for preparing a hybrid optical cable of hollow and solid optical fibers, which includes the following steps:

[0084] Obtain reinforcement 1, and a receiving groove 4 is formed on the outer periphery of reinforcement 1;

[0085] The traction reinforcement 1 has the first optical unit 2 and the second optical unit 3 twisted together and disposed on the outer periphery of the reinforcement 1, and the first optical unit 2 is embedded in the receiving groove 4;

[0086] An outer sheath 5 is extruded around the first optical unit 2 and the second optical unit 3.

[0087] Alternatively, the reinforcing member 1 in this invention can be directly formed into a receiving groove 4 during preparation, or the receiving groove 4 can be formed through subsequent processing. The shape of the receiving groove 4 is consistent with the twisting path of the first optical unit 2.

[0088] Alternatively, after the first optical unit 2 and the second optical unit 3 are twisted together on the outer periphery of the reinforcing member 1, the first optical unit 2 and the second optical unit 3 can be fixed to the surface of the reinforcing member 1 by means of yarn binding.

[0089] Alternatively, the first light unit 2 and the second light unit 3 can be fixed to the surface of the reinforcing member 1 by intermittently applying adhesive to the surfaces where the first light unit 2 and the second light unit 3 are in contact with the reinforcing member 1.

[0090] The following describes the fabrication of a hybrid optical cable with hollow and solid optical fibers having the same diameter as the first optical unit 2 and the second optical unit 3 (Example 1), a hybrid optical cable with hollow and solid optical fibers of the present invention (Example 2), and a hybrid optical cable with hollow and solid optical fibers without the receiving slot 4 on the reinforcing member 1 (Example 3). The minimum bending radius and bending loss of the hollow optical fiber 7 in each hybrid optical cable were tested. Specifically, in the above hybrid optical cables, FRP is used as the reinforcing member 1, and the receiving slot 4 on the reinforcing member 1 is arc-shaped; the first optical unit 2 and the second optical unit 3 are both made of polyamide loose tubes, and the outer sheath 5 is made of polyethylene.

[0091]

[0092] Based on the above comparison, it can be seen that the hollow and solid fiber hybrid optical cable of the present invention reduces the additional cable loss of hollow fiber in the 1550nm band through the structure design of the accommodating slot 4; in addition, its minimum bending radius is smaller than that of conventional hollow and solid fiber hybrid cable and much smaller than that of hollow and solid fiber hybrid irregular cable, making it suitable for more narrow and curved environments.

[0093] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A hybrid optical cable containing hollow and solid optical fibers, characterized in that, include: Reinforcing components; Multiple optical units, wherein the multiple optical units include at least one first optical unit and at least one second optical unit; The first optical unit contains at least one hollow optical fiber, and the second optical unit contains at least one solid optical fiber. The diameter of the first optical unit is larger than the diameter of the second optical unit. The first optical unit and the second optical unit are twisted together on the outer periphery of the reinforcing member. The reinforcing member is provided with at least one receiving groove along the axial direction. The receiving groove extends along the surface of the reinforcing member along the same path as the twisting path of the first optical unit. The first optical unit is partially embedded in the receiving groove. The inner surface of the receiving groove is a concave arc surface, and the radius of the arc surface of the receiving groove is the same as the radius of the first optical unit. The first optical unit is attached to the inner wall of the receiving groove. The outer sheath wraps around the outer periphery of the twisted structure of the first optical unit and the second optical unit; Wherein, the diameter of the first optical unit is L1, the diameter of the second optical unit is L2, the diameter of the reinforcing member is L3, the twisting pitch of the first optical unit and the second optical unit is d, and the diameters of the first optical unit, the second optical unit, the reinforcing member, and the twisting pitch of the first optical unit satisfy the following relationship: 。 2. The hybrid optical cable of hollow and solid optical fibers according to claim 1, characterized in that, The non-circularity of the hybrid optical fiber cable containing hollow and solid fibers is no greater than 5%.

3. The hybrid optical cable containing hollow and solid optical fibers according to claim 1 or 2, characterized in that, The difference between the diameter of the first optical unit and the diameter of the second optical unit is equal to the maximum depth to which the first optical unit is embedded in the receiving groove.

4. The hybrid optical cable of hollow and solid optical fibers according to claim 3, characterized in that, The diameter of the first optical unit is L1, the diameter of the second optical unit is L2, the twist pitch of the first optical unit and the second optical unit is both d, and the bending radius r1 of the first optical unit is: The bending radius r2 of the second optical unit is: 。 5. The hybrid optical cable of hollow and solid optical fibers according to claim 4, characterized in that, The duty cycle inside the first optical unit is 5% to 50%.

6. The hybrid optical cable containing hollow and solid optical fibers according to claim 1 or 2, characterized in that, The outer periphery of the twisted structure of the first optical unit and the second optical unit is wrapped with binding yarn.

7. The hybrid optical cable containing hollow and solid optical fibers according to claim 1 or 2, characterized in that, The first optical unit and the second optical unit are intermittently bonded to the outer wall of the reinforcing member along the axial direction by adhesive.

8. The hybrid optical cable containing hollow and solid optical fibers according to claim 1 or 2, characterized in that, The number of fiber cores in the first optical unit is the same as the number of fiber cores in the second optical unit; The hollow fiber is an anti-resonant hollow fiber, and the solid fiber is a single-mode fiber or a multimode fiber.

9. A method for preparing a hybrid optical cable of hollow and solid optical fibers, used to prepare a hybrid optical cable of hollow and solid optical fibers as described in any one of claims 1 to 8, characterized in that, Includes the following steps: A reinforcing member is obtained, wherein a receiving groove is formed on the outer periphery of the reinforcing member; A traction reinforcement member is provided, wherein the first optical unit and the second optical unit are twisted together and disposed on the outer periphery of the reinforcement member, and the first optical unit is embedded in the receiving groove; An outer sheath is extruded around the first optical unit and the second optical unit.

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