Optical fiber ribbon and optical cable

Abstract

The present application relates to an optical fiber ribbon and an optical cable. The optical fiber ribbon comprises at least one core ribbon group, which comprises three optical fiber units arranged in parallel, wherein one of the optical fiber units comprises one optical fiber; another one of the optical fiber units comprises two optical fibers arranged in parallel, the two optical fibers being completely connected in the direction of length of the optical fibers by means of a continuous connection portion; the remaining optical fiber unit comprises three optical fibers arranged in parallel, two adjacent optical fibers being completely connected in the direction of length of the optical fibers by means of a continuous connection portion; and two adjacent optical fiber units are discontinuously connected in the direction of length of the optical fibers by means of first discontinuous connection portions. The present application uses three types of optical fiber units with different numbers of optical fibers. The optical fiber ribbon having six optical fibers uses intermittent bonds only between two groups of optical fiber units, thus reducing the number of intermittent bonds on the optical fiber ribbon. Therefore, the probability of the optical fiber ribbon breaking during subsequent winding and bundling can be reduced to a certain extent, thereby preventing micro-bending of the optical fibers caused by the worsening of lateral pressure between the optical fibers.

Description

An optical fiber ribbon and optical cable Technical Field

[0001] This application relates to the field of optical fiber communication technology, and in particular to an optical fiber ribbon and optical cable. Background Technology

[0002] In recent years, with the vigorous advancement of "all-optical network" construction, the construction of traditional underground access networks has faced new challenges. While making full use of existing underground facilities, the demand for ultra-high core count and high fiber density optical cables is increasing. How to increase the core count of optical cables while maintaining their original outer diameter has become a direction for industry exploration. Existing flat fiber ribbon cables have received considerable attention due to their high density, high integration, light weight, and ease of multi-fiber splicing, and are widely used in ultra-high core count optical cables. However, due to the size limitations of existing flat fiber ribbon cables, the size of optical cables with the same core count is also relatively large, making it difficult to make more rational and effective use of existing conduits and space.

[0003] To address the limitations of flat fiber ribbons in terms of size and the constraints imposed by their bending direction, Japanese fiber optic cable manufacturers such as Fujikura and Sumitomo have developed rollable fiber ribbons. These ribbons are flat, with each single fiber core or two cores partially bonded along their length; this type is also known as spaced-bonded fiber ribbons. While retaining the advantages of flat fiber ribbons in installation and splicing, these ribbons can be wound into bundled fiber units, effectively reducing the ribbon's volume and increasing core density. Furthermore, manufacturers such as Corning (USA) and Priesmann (Italy) also offer flat fiber ribbons made of flexible resin, which are rollable and used as fiber units in the manufacture of ultra-high core count optical cables.

[0004] However, the above-mentioned solutions still have some drawbacks. For example, since the optical fiber ribbon is flat, in order to increase the density of the optical fiber ribbon in the optical cable, the flat optical fiber ribbon needs to be wound into a bundle. However, in the process of winding the optical fiber ribbon into a bundle, because each optical fiber is bonded in a point-like manner, the possibility of the optical fiber being broken increases, which will cause the optical fiber to be slightly bent. Summary of the Invention

[0005] This application provides an optical fiber ribbon and optical cable to solve the problem in the related art where, during the process of winding the optical fiber ribbon into a bundle, the possibility of the optical fiber being broken increases, and the lateral pressure characteristics between the optical fibers tend to deteriorate due to the breakage of the bonding of the optical fibers in the optical fiber ribbon, which will cause micro-bending of the optical fiber.

[0006] In a first aspect, an optical fiber ribbon is provided, comprising at least one core strip group, the core strip group comprising three optical fiber units arranged side by side;

[0007] One of the optical fiber units includes a single optical fiber;

[0008] Another of the fiber units includes two optical fibers arranged side by side, and the two optical fibers are completely connected in the fiber length direction by a continuous connection portion;

[0009] The remaining one of the fiber units includes three optical fibers arranged side by side, and two adjacent optical fibers are completely connected in the fiber length direction by a continuous connection portion;

[0010] Two adjacent fiber units are intermittently connected in the fiber length direction by a first intermittent connection portion.

[0011] In some embodiments, in the core ribbon group, between the two fiber units on the two sides respectively, the first intermittent connection portion between the fiber unit with a smaller number of optical fibers and the fiber unit in the middle position is provided with m, the first intermittent connection portion between the fiber unit with a larger number of optical fibers and the fiber unit in the middle position is provided with n, and m>n.

[0012] In some embodiments, of the m first intermittent connection portions between the fiber unit with a smaller number of optical fibers and the fiber unit in the middle position, n first intermittent connection portions are aligned with the n first intermittent connection portions between the fiber unit with a larger number of optical fibers and the fiber unit in the middle position along the core ribbon group width direction.

[0013] In some embodiments, the fiber ribbon includes a plurality of core ribbon groups, the plurality of core ribbon groups are arranged side by side, and two adjacent core ribbon groups are intermittently connected in the fiber length direction by a second intermittent connection portion.

[0014] In some embodiments, the second intermittent connection portion is arranged staggered with the first intermittent connection portion along the fiber length direction.

[0015] In some embodiments, the optical fiber is a single-mode optical fiber or a multi-mode optical fiber, wherein the single-mode optical fiber is a single-core single-mode optical fiber, a multi-core optical fiber containing a plurality of cores, or a hollow-core optical fiber.

[0016] In some embodiments, the diameter of the optical fiber is 165 um, 180 um, 200 um, 250 um, or 400 um.

[0017] In some embodiments, the diameters of the optical fibers in each fiber unit are equal or unequal.

[0018] In a second aspect, a fiber cable is provided, which includes:

[0019] An outer sheath;

[0020] and a plurality of fiber ribbons as described in any of the above, which are contained in the outer sheath.

[0021] In some embodiments, the outer sheath is made of polyethylene, low-smoke halogen-free, polyvinyl chloride or nylon.

[0022] The beneficial effects brought by the technical solutions provided in the application include:

[0023] The optical fiber ribbon and the optical cable provided in the embodiments of the application, in the related art, the manufactured optical fiber ribbon is flat, at this time, the stress of the optical fiber ribbon is basically eliminated, when the flat optical fiber ribbon is wound into a bundle, the winding stress of the optical fiber is large, since the adjacent optical fibers are all sparsely bonded, the sparsely bonded positions are too many, and the optical fiber bonding position is prone to be disconnected, the optical fiber ribbon provided in the embodiments has three different optical fiber units with different numbers of optical fibers, the optical fiber ribbon with six optical fibers has only two groups of optical fiber units sparsely bonded, the number of sparsely bonded positions of the optical fiber ribbon is reduced, and therefore the possibility of disconnection of the optical fiber ribbon in the subsequent winding process into a bundle can be reduced to a certain extent, and then the micro-bending of the optical fiber caused by the deterioration of the lateral pressure between the optical fibers is avoided. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the application, the drawings needed to be used in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0025] FIG. 1 is a schematic diagram of the optical fiber ribbon provided in the embodiments of the application in a first state (one core ribbon group, 123 mode);

[0026] FIG. 2 is a schematic diagram of the optical fiber ribbon provided in the embodiments of the application in a second state (one core ribbon group, 123 mode);

[0027] FIG. 3 is a schematic diagram of the optical fiber ribbon provided in the embodiments of the application in a first state (one core ribbon group, 132 mode);

[0028] FIG. 4 is a schematic diagram of the optical fiber ribbon provided in the embodiments of the application in a second state (one core ribbon group, 132 mode);

[0029] FIG. 5 is a schematic diagram of the optical fiber ribbon provided in the embodiments of the application in a first state (one core ribbon group, 213 mode);

[0030] FIG. 6 is a schematic diagram of the optical fiber ribbon provided in the embodiments of the application in a second state (one core ribbon group, 213 mode);

[0031] FIG. 7 is a schematic diagram of the optical fiber ribbon provided in the embodiments of the application in a first state (two core ribbon groups, 123 mode);

[0032] Fig. 8 is a schematic diagram of the optical fiber ribbon in the second state (two core ribbon groups, 123 mode) according to an embodiment of the present application;

[0033] Fig. 9 is a schematic diagram of an optical cable according to an embodiment of the present application.

[0034] In the figure: 1, optical fiber unit; 2, optical fiber; 3, continuous connection part; 4, first intermittent connection part; 5, second intermittent connection part; 6, outer sheath; 100, core ribbon group. DETAILED DESCRIPTION

[0035] To make the objectives, technical solutions, and superiorities of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described below in connection with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0036] Referring to Fig. 1, the present application provides an optical fiber ribbon, which comprises at least one core ribbon group 100, the core ribbon group 100 comprising three optical fiber units 1 arranged side by side, one of the optical fiber units 1 comprising one optical fiber 2; another of the optical fiber units 1 comprising two optical fibers 2 arranged side by side, and the two optical fibers 2 being completely connected in the length direction of the optical fibers 2 by a continuous connection part 3; the remaining one of the optical fiber units 1 comprising three optical fibers 2 arranged side by side, and adjacent two of the optical fibers 2 being completely connected in the length direction of the optical fibers 2 by a continuous connection part 3; adjacent two of the optical fiber units 1 being intermittently connected in the length direction of the optical fibers 2 by a first intermittent connection part 4.

[0037] It can be understood that the continuous connection part 3 extends to the two ends of the optical fibers 2 in the length direction of the optical fibers 2, and the optical fiber unit 1 has a certain rigidity by the continuous connection part 3, and the first intermittent connection part 4 is arranged in a spaced distribution manner between adjacent two of the optical fiber units 1, so that each of the optical fiber units 1 has a certain flexibility. The combination of rigidity and flexibility makes the optical fiber ribbon reach a balance between rigidity and flexibility, ensuring that the optical fiber ribbon can be smoothly rolled when making an optical cable, and can be smoothly laid in a flat state when fusion splicing, thereby ensuring the mechanical performance, transmission performance, and operability of the optical fiber ribbon in construction and fusion splicing.

[0038] In the present application, the three optical fiber units 1 have a total of six optical fibers 2, which are connected into a whole by the continuous connection part 3 and the first intermittent connection part 4, so that the optical fiber ribbon has two states, namely a first state and a second state, and the first state and the second state can be switched.

[0039] Specifically, referring to FIG. 1, when in the first state, each optical fiber unit 1 can form a flat state. Referring to FIG. 2, when the optical fiber unit 1 is moved and wound when the optical fiber ribbon is manufactured into an optical cable, the optical fiber ribbon is switched from the first state to the second state to form a bundle-shaped structure, facilitating the dense arrangement of the optical fiber ribbon.

[0040] When the optical fiber ribbon needs to be spliced, the entire optical fiber ribbon in the optical cable can be laid flat to facilitate one-time splicing, retaining the convenience of conventional flat optical fiber ribbon splicing.

[0041] In the related art, the manufactured optical fiber ribbon is flat, and at this time, the stress of the optical fiber ribbon is basically eliminated. When the flat optical fiber ribbon is wound into a bundle, the optical fiber is subjected to a large winding stress. Since the adjacent optical fibers are connected by spacing and bonding, the spacing and bonding positions are too many, and the optical fiber bonding position is prone to breakage. The optical fiber ribbon provided in the embodiment has three different optical fiber units with different numbers of optical fibers. The optical fiber ribbon with six optical fibers 2 has only two groups of optical fiber units connected by spacing and bonding, reducing the number of spacing and bonding of the optical fiber ribbon, and thus the possibility of breakage of the optical fiber ribbon during subsequent winding into a bundle can be reduced to a certain extent, thereby avoiding the deterioration of the lateral pressure between the optical fibers and causing micro-bending of the optical fibers.

[0042] The optical fiber ribbon can be switched between two states, can be easily wound into a bundle-shaped optical fiber, and effectively reduces the size and occupied volume of the optical fiber ribbon. The optical cable manufactured using the optical fiber ribbon provided in the embodiment can effectively reduce the outer diameter and weight of the optical cable itself under the premise of meeting the same mechanical performance, transmission performance, and operable performance of splicing, greatly increasing the total core number of the optical cable and improving the fiber core density.

[0043] In addition, since the production efficiency of full connection between optical fibers is much higher than that of intermittent connection between optical fibers, the optical fibers in the optical fiber unit are connected in full connection, and three fixed optical fiber units are used, which helps to improve the production efficiency.

[0044] During production and manufacturing, the optical fibers can be marked, such as coloring, to facilitate subsequent splicing.

[0045] Further, the three different optical fiber units with different numbers of optical fibers have three arrangement modes when connected.

[0046] The first arrangement mode is the 123 mode.

[0047] Referring to FIGS. 1 and 2, specifically, the middle is the optical fiber unit 1 with two optical fibers 2, one side is intermittently connected to the optical fiber unit 1 with one optical fiber 2, and the other side is intermittently connected to the optical fiber unit 1 with three optical fibers 2.

[0048] The second arrangement mode: 132 mode

[0049] Referring to FIGS. 3 and 4, specifically, the middle is the optical fiber unit 1 with three optical fibers 2, one side is intermittently connected with the optical fiber unit 1 with one optical fiber 2, and the other side is intermittently connected with the optical fiber unit 1 with two optical fibers 2.

[0050] The third arrangement mode: 213 mode

[0051] Referring to FIGS. 5 and 6, specifically, the middle is the optical fiber unit 1 with one optical fiber 2, one side is intermittently connected with the optical fiber unit 1 with three optical fibers 2, and the other side is intermittently connected with the optical fiber unit 1 with two optical fibers 2.

[0052] Since the optical fiber unit 1 has a certain rigidity by the continuous connection part 3, it can be understood that the more the number of optical fibers 2, the greater the rigidity of the full connection of the optical fiber unit 1. When the continuous connection part 3 is completely cured, the amount of cured resin on the surface of each optical fiber unit is inconsistent, which leads to inconsistent temperature shrinkage under high and low temperature conditions, and the stress generated during shrinkage also varies. Therefore, in some preferred embodiments, in order to ensure the consistency of the shrinkage of the optical fiber unit and reduce the difference in stress influence in the length direction between the optical fiber units due to the difference in rigidity, the first intermittent connection part 4 between the optical fiber unit 1 with fewer optical fibers 2 and the optical fiber unit 1 located in the middle position is provided with m in each meter of length, and the first intermittent connection part 4 between the optical fiber unit 1 with more optical fibers 2 and the optical fiber unit 1 located in the middle position is provided with n, and m>n.

[0053] Specifically, referring to FIG. 1, if the first arrangement mode is adopted, the first intermittent connection part 4 between the optical fiber unit 1 with two optical fibers 2 and the optical fiber unit 1 with one optical fiber 2 is provided with m in each meter of length, and the first intermittent connection part 4 between the optical fiber unit 1 with two optical fibers 2 and the optical fiber unit 1 with three optical fibers 2 is provided with n.

[0054] Referring to FIG. 3, if the second arrangement mode is adopted, the first intermittent connection part 4 between the optical fiber unit 1 with three optical fibers 2 and the optical fiber unit 1 with one optical fiber 2 is provided with m in each meter of length, and the first intermittent connection part 4 between the optical fiber unit 1 with three optical fibers 2 and the optical fiber unit 1 with two optical fibers 2 is provided with n.

[0055] Referring to Fig. 5, if the third arrangement is adopted, m first intermittent connection portions 4 are arranged between the optical fiber unit 1 containing one optical fiber 2 and the optical fiber unit 1 containing two optical fibers 2 per meter, and n first intermittent connection portions 4 are arranged between the optical fiber unit 1 containing one optical fiber 2 and the optical fiber unit 1 containing three optical fibers 2 per meter.

[0056] In some preferred embodiments, n of the m first intermittent connection portions 4 between the optical fiber unit 1 containing a small number of optical fibers 2 and the optical fiber unit 1 located in the middle position are aligned with n of the n first intermittent connection portions 4 between the optical fiber unit 1 containing a large number of optical fibers 2 and the optical fiber unit 1 located in the middle position along the width direction of the core ribbon group 100. The advantage of this alignment is to reduce the internal stress caused by the contraction or elongation of the optical fiber in the length direction, to ensure that the number of connection points is reduced when the optical fiber contracts or elongates when the temperature changes, thereby reducing the attenuation performance of the optical fiber under micro-bending, and in addition, the advantage of multi-point alignment is to reduce the complexity of the process.

[0057] Referring to Figs. 7 and 8, in some preferred embodiments, the optical fiber ribbon includes a plurality of core ribbon groups 100, and the plurality of core ribbon groups 100 are arranged side by side, and two adjacent core ribbon groups 100 are intermittently connected in the length direction of the optical fiber 2 by a second intermittent connection portion 5.

[0058] Referring to Fig. 7, in some preferred embodiments, the second intermittent connection portion 5 is arranged staggered with the first intermittent connection portion 4 along the length direction of the optical fiber 2. This staggered arrangement can reduce the stress of the optical fiber ribbon when it is wound and bent, and avoid the concentration of bending stress on the same cross section in the width direction, which can cause damage to the adhesive points.

[0059] In some preferred embodiments, the optical fiber 2 is a single-mode optical fiber or a multi-mode optical fiber, such as G.652, G.654, G.657, etc.

[0060] In some preferred embodiments, the single-mode optical fiber is a single-core single-mode optical fiber, a multi-core optical fiber containing multiple cores, or a hollow-core optical fiber.

[0061] Preferably, in order to increase the number of optical fiber cores, the optical fiber can be a multi-core optical fiber, such as a 2-core optical fiber, a 4-core optical fiber, a 7-core optical fiber, etc.

[0062] In some preferred embodiments, the diameter of the optical fiber 2 is 165 um, 180 um, 200 um, 250 um, or 400 um.

[0063] In some preferred embodiments, the diameters of the optical fibers 2 in each optical fiber unit 1 are equal or unequal.

[0064] Referring to FIG. 9, the optical cable of the present application comprises an outer sheath 6; and a plurality of optical fiber ribbons as described above, which are accommodated in the outer sheath 6.

[0065] The outer sheath 6 is made of an extrudable polymer sheath material, such as polyethylene, low-smoke halogen-free, polyvinyl chloride or nylon.

[0066] In some preferred embodiments, the first intermittent connection 4, the second intermittent connection 5 and the continuous connection 3 are made of light-cured resin to ensure production efficiency. In addition, in the case of low production efficiency, heat-cured glue or heat-sensitive glue with double-sided adhesive properties can also be used.

[0067] In some preferred embodiments, the linear expansion coefficient of the light-cured resin at room temperature is less than 8x10 -4 / ℃, and the elongation at break is greater than 50%.

[0068] In some preferred embodiments, the distance between the first intermittent connections 4 of two adjacent optical fiber units 1 is greater than the length of the first intermittent connection 4 in the length direction of the optical fiber 2. The length of the adhesive part is less than that of the non-adhesive part, and the overall proportion of the non-connection part is increased, which can help the optical fiber ribbon to achieve high flexibility, facilitate the winding movement of the optical fiber, and also reduce the stress control difficulty of the optical fiber in the adhesive part during rotation and paving. In addition, the resin usage can be reduced, and the cost can be reduced.

[0069] Embodiment One

[0070] The optical fiber ribbon of the present application is shown in FIG. 1, which is a 6-core optical fiber ribbon. The optical fiber ribbon is made of three groups of optical fiber units spaced and bonded. The first group of optical fiber units contains one optical fiber, which is a G.652.D single-mode optical fiber with a colored outer diameter of 250um and a blue color. The second group of optical fiber units contains two optical fibers, which are G.652.D single-mode optical fibers with colored outer diameters of 250um and orange and green colors, and the two optical fibers are completely connected in the length direction. The third group of optical fiber units contains three optical fibers, which are G.652.D single-mode optical fibers with colored outer diameters of 250um and brown, gray and white colors, and the three optical fibers are completely connected in the length direction. According to the combination order of the first group, the second group and the third group of optical fiber units, the number of first intermittent connections between the first group of optical fiber units and the second group of optical fiber units is greater than the number of first intermittent connections between the second group of optical fiber units and the third group of optical fiber units per 1m in length. The material of the first intermittent connection is ultraviolet light-cured resin, and the curing shrinkage is less than 8%.

[0071] Embodiment Two

[0072] The optical fiber ribbon of the second embodiment is shown in FIG. 7, which is a 12-core optical fiber ribbon formed by spacing and bonding two groups of 6-core optical fiber ribbons in the first embodiment, wherein the 6-core optical fiber ribbons can be the same type of optical fiber ribbon (i.e., the same arrangement combination), or two different arrangement combinations of 6-core optical fiber ribbons can be spaced and fixed by the second intermittent connecting portion, and the optical fiber type is G.657 optical fiber, and the colored diameter of a single optical fiber is 200 um.

[0073] In the description of the present application, it should be noted that the terms "upper", "lower", and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. Unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0074] It should be noted that in the present application, relational terms such as "first" and "second" and the like are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the terms "include", "contain" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or device. Without more limitations, the element defined by the sentence "including a…" does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0075] The above is only a specific embodiment of the present application, which enables those skilled in the art to understand or implement the present application. Various modifications of these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features applied herein.

Claims

1. An optical fiber ribbon, characterized by: It comprises at least one core ribbon group (100), the core ribbon group (100) comprising three optical fiber units (1) arranged side by side; One of the optical fiber units (1) comprises one optical fiber (2); Another of the optical fiber units (1) comprises two optical fibers (2) arranged side by side, and the two optical fibers (2) are completely connected in the length direction of the optical fibers (2) by a continuous connection (3); The remaining one of the optical fiber units (1) comprises three optical fibers (2) arranged side by side, and two adjacent optical fibers (2) are completely connected in the length direction of the optical fibers (2) by a continuous connection (3); Two adjacent optical fiber units (1) are intermittently connected in the length direction of the optical fibers (2) by a first intermittent connection (4).

2. The optical fiber ribbon according to claim 1, wherein: the first intermittent connections (4) between the optical fiber unit (1) with fewer optical fibers (2) and the optical fiber unit (1) in the middle position are provided with m, and the first intermittent connections (4) between the optical fiber unit (1) with more optical fibers (2) and the optical fiber unit (1) in the middle position are provided with n, and m > n.

3. The optical fiber ribbon according to claim 2, wherein: the m first intermittent connections (4) between the optical fiber unit (1) with fewer optical fibers (2) and the optical fiber unit (1) in the middle position are aligned with the n first intermittent connections (4) between the optical fiber unit (1) with more optical fibers (2) and the optical fiber unit (1) in the middle position in the width direction of the core ribbon group (100).

4. The optical fiber ribbon according to claim 1, wherein: the optical fiber ribbon comprises a plurality of core ribbon groups (100), the plurality of core ribbon groups (100) are arranged side by side, and two adjacent core ribbon groups (100) are intermittently connected in the length direction of the optical fibers (2) by a second intermittent connection (5).

5. The optical fiber ribbon according to claim 4, wherein: the second intermittent connections (5) and the first intermittent connections (4) are arranged staggered in the length direction of the optical fibers (2).

6. The optical fiber ribbon according to claim 1, wherein: the optical fibers (2) are single-mode optical fibers or multi-mode optical fibers, and the single-mode optical fibers are single-core single-mode optical fibers, multi-core optical fibers containing multiple cores, or hollow-core optical fibers.

7. The optical fiber ribbon according to claim 1, wherein: the diameter of the optical fibers (2) is 165 um, 180 um, 200 um, 250 um, or 400 um.

8. The optical fiber ribbon according to claim 1, wherein: the diameters of the optical fibers (2) in each optical fiber unit (1) are equal or unequal. It comprises: an outer sheath (6); and a plurality of optical fiber ribbons according to any one of claims 1 to 8, which are contained in the outer sheath (6). ​ ​ ​ ​ ​ 9. An optical cable characterized by, ​ ​ ​ 10. The optical cable of claim 9, wherein: The outer sheath (6) is made of polyethylene, low-smoke halogen-free, polyvinyl chloride or nylon.

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