Large-mode-field small-diameter single-mode optical fiber and miniature optical cable

Abstract

The utility model relates to a small-diameter single-mode optical fiber with a large mode field and a miniature optical cable, and the optical fiber comprises a core layer which is 8.5-9.5 [mu] m in diameter; the inner coating layer is coated on the periphery of the core layer, and the diameter of the inner coating layer is 124.3 to 125.7 [mu] m; the inner coating layer is coated on the periphery of the inner cladding layer, and the diameter of the inner coating layer is 140 to 150 microns; and the outer coating is coated on the periphery of the inner coating, and the diameter of the outer coating is 175 to 185 microns. The core layer, the inner cladding layer, the inner coating layer and the outer coating layer jointly form the small-diameter single-mode optical fiber with the diameter of 180 microns, and the small-diameter single-mode optical fiber can be applied to micro-cable products with smaller outer diameters. The fiber type of the small-diameter single-mode optical fiber is G.653. A1, and the small-diameter single-mode optical fiber has good macro-bending performance; meanwhile, the mode field diameter of the small-diameter single-mode optical fiber at the wavelength of 1310 nm is 9 microns, the small-diameter single-mode optical fiber can be completely compatible with a G.652. D single-mode optical fiber commonly used in the market, the one-way welding loss of the small-diameter single-mode optical fiber and the G.652. D single-mode optical fiber is smaller than 0.1 dB, and market sale and engineering application are better facilitated.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of optical fibers, and in particular to a large-mode-area thin-diameter single-mode optical fiber and a micro optical cable. BACKGROUND

[0002] The data flow of the information society is growing explosively, and the pressure on the optical network, which is the foundation of information data transmission, is highlighted. The transmission capacity needs to be improved as a top priority. However, the problem of limited cable pipeline resources is becoming increasingly serious, and needs to be solved by reducing the diameter of the optical fiber and increasing the number of optical fibers in the unit area of the optical cable. For example, in European countries such as the Netherlands and Belgium, the inner hole of the new optical fiber protection tube has been changed from 8 mm to 7 mm. The size of the micro cable produced using a 200-μm-diameter optical fiber coating cannot meet the requirements, and a 180-μm optical fiber needs to be used for production, further reducing the size of the micro cable. Therefore, smaller-sized optical fibers and optical cables are the trend of the development of the optical communication industry.

[0003] Compared with the conventional 245-μm optical fiber, the 180-μm thin-diameter optical fiber has a 50% reduction in coating thickness, and the protection capability of the bare optical fiber is poor. It is easy to generate a large additional attenuation of the optical fiber due to stress in the cabling process, environmental and mechanical performance tests, and optical cable construction process. In order to improve the stress resistance of the optical fiber, the glass layer and the coating layer of the optical fiber can be improved.

[0004] The existing 180-μm thin-diameter optical fiber mainly improves the stress resistance of the optical fiber by improving the macro-bending performance of the glass layer. The macro-bending performance of the optical fiber needs to exceed the standard requirement of G.657.A2. However, such an optical fiber belongs to a small-mode-area single-mode optical fiber, and the profile design of the glass layer of the optical fiber is greatly different from that of the conventional G.652.D optical fiber, and cannot be fusion spliced with the G.652.D optical fiber (or the fusion splicing loss exceeds 0.5 dB). In actual applications, there are problems such as the inability to be fusion spliced in the construction process, and the unqualified link attenuation caused by large fusion splicing loss in the link. SUMMARY

[0005] Embodiments of the present application provide a large-mode-area thin-diameter single-mode optical fiber and a micro optical cable to solve the problem that the glass layer of the thin-diameter optical fiber in the related art cannot be fusion spliced with the G.652.D optical fiber.

[0006] The first aspect of the embodiments of the present application provides a large-mode-area thin-diameter single-mode optical fiber, comprising:

[0007] a core layer, the diameter of the core layer being 8.5-9.5 μm;

[0008] an inner cladding layer, the inner cladding layer being coated on the outer periphery of the core layer, and the diameter of the inner cladding layer being 124.3-125.7 μm;

[0009] an inner coating layer, the inner coating layer being coated on the outer periphery of the inner cladding layer, the diameter of the inner coating layer being 140-150 μm;

[0010] an outer coating layer, the outer coating layer being coated on the outer periphery of the inner coating layer, the diameter of the outer coating layer being 175-185 μm.

[0011] In some embodiments: the mode field diameter of the thin single-mode optical fiber at a wavelength of 1310 nm is 8.8-9.6 μm.

[0012] In some embodiments: the mode field diameter of the thin single-mode optical fiber at a wavelength of 1310 nm is 9 μm.

[0013] In some embodiments: the modulus of elasticity of the inner coating layer is 0.2-0.4 MPa, the breaking strength is ≥ 30 MPa, the breaking elongation is ≥ 20%, and the Tg is ≤ -20℃;

[0014] the modulus of elasticity of the outer coating layer is 700-1000 MPa, the Tg is ≤ 90℃, and the expansion coefficient is 70-130 K.

[0015] In some embodiments: the water permeability of the thin single-mode optical fiber is in the range of 20-50 g / (m 2 .day).

[0016] In some embodiments: the macrobending performance of the thin single-mode optical fiber satisfies that the macrobending loss at a wavelength of 1550 nm is ≤ 0.5 dB and the macrobending loss at a wavelength of 1625 nm is ≤ 1.5 dB when being bent 1 circle with a diameter of 20 mm;

[0017] the macrobending loss at a wavelength of 1550 nm is ≤ 0.15 dB and the macrobending loss at a wavelength of 1625 nm is ≤ 0.5 dB when being bent 10 circles with a diameter of 30 mm.

[0018] In some embodiments: the additional attenuation of the thin single-mode optical fiber at a working wavelength of 1310 nm, 1383 nm, 1550 nm and 1625 nm is all ≤ 0.03 dB / km under a temperature environment of -60℃-85℃.

[0019] In some embodiments: the average peeling force of the inner coating layer and the outer coating layer of the thin single-mode optical fiber is greater than 1 N.

[0020] A second aspect of the embodiments of the present application provides a micro optical cable, which comprises the thin single-mode optical fiber according to any one of the above embodiments.

[0021] In some embodiments: 96 thin single-mode optical fibers are arranged in the micro optical cable, and the outer diameter of the micro optical cable is 4.7 mm.

[0022] Or, the micro cable is provided with 144 fine-diameter single-mode optical fibers, and the outer diameter of the micro cable is 5 mm.

[0023] The technical scheme provided by the application has the beneficial effects of:

[0024] The application provides a large-mode-field fine-diameter single-mode optical fiber and a micro cable. The large-mode-field fine-diameter single-mode optical fiber is provided with a core layer with a diameter of 8.5-9.5 μm, an inner cladding layer covering the outer periphery of the core layer and having a diameter of 124.3-125.7 μm, an inner coating layer covering the outer periphery of the inner cladding layer and having a diameter of 140-150 μm, and an outer coating layer covering the outer periphery of the inner coating layer and having a diameter of 175-185 μm.

[0025] Therefore, the core layer, the inner cladding layer, the inner coating layer and the outer coating layer of the large-mode-field fine-diameter single-mode optical fiber jointly form a fine-diameter single-mode optical fiber with a diameter of 180 μm, which can be applied to micro cable products with a smaller outer diameter. The fine-diameter single-mode optical fiber has a fiber type of G.657.A1 and has good macro-bending performance. Meanwhile, the fine-diameter single-mode optical fiber has a mode field diameter of 9 μm at a wavelength of 1310 nm, which is completely compatible with the commonly used G.652.D single-mode optical fiber in the market, and the one-way fusion splicing loss of the fine-diameter single-mode optical fiber and the G.652.D single-mode optical fiber is less than 0.1 dB, which is more conducive to market sales and engineering application. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical scheme in the embodiments of the application, the drawings needed in the embodiment description will be briefly introduced. 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 creative effort.

[0027] Figure 1 The drawings are schematic cross-sectional views of the embodiments of the application.

[0028] Reference signs:

[0029] 1, core layer; 2, inner cladding layer; 3, inner coating layer; 4, outer coating layer. DETAILED DESCRIPTION

[0030] To make the purposes, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0031] The embodiments of the present application provide a large-mode-field thin-diameter single-mode optical fiber and a micro optical cable, which can solve the problem that the fiber glass layer of the thin-diameter optical fiber cannot be fusion spliced with a G.652.D optical fiber in the related art.

[0032] Referring to Figure 1 The first aspect of the embodiments of the present application provides a large-mode-field thin-diameter single-mode optical fiber, comprising:

[0033] The core layer 1 has a diameter of 8.5-9.5 μm, and the diameter of the core layer 1 is further preferably 9 μm. The core layer 1 is the central part of the thin-diameter single-mode optical fiber and is the transmission path of light.

[0034] The inner cladding layer 2 is coated on the outer periphery of the core layer 1, and the refractive index of the inner cladding layer 2 is smaller than that of the core layer 1, so that light can be totally reflected in the core layer 1 and thus propagate in the optical fiber. The diameter of the inner cladding layer 2 is 124.3-125.7 μm, and the diameter of the inner cladding layer 2 is further preferably 125 μm.

[0035] The inner coating layer 3 is coated on the outer periphery of the inner cladding layer 2, and the diameter of the inner cladding layer 2 is 140-150 μm, and the diameter of the inner cladding layer 2 is further preferably 145 μm.

[0036] The outer coating layer 4 is coated on the outer periphery of the inner coating layer 3, and the diameter of the outer coating layer 4 is 175-185 μm, and the diameter of the outer coating layer 4 is further preferably 180 μm.

[0037] The inner coating layer 3 and the outer coating layer 4 serve as the coating layer of the thin-diameter single-mode optical fiber, and their main function is to protect the core layer 1 from physical damage and environmental influences such as humidity and temperature changes. In addition, the inner coating layer 3 and the outer coating layer 4 can also provide certain mechanical strength to prevent the multi-core optical fiber 1 from being stretched and bent during installation and use.

[0038] The mode field diameter of the thin-diameter single-mode optical fiber at a wavelength of 1310 nm is 8.8-9.6 μm, and further, the mode field diameter of the thin-diameter single-mode optical fiber at a wavelength of 1310 nm is 9 μm.

[0039] The core layer 1, the inner cladding layer 2, the inner coating layer 3 and the outer coating layer 4 of the large-mode-field thin single-mode optical fiber of the present application jointly form a thin single-mode optical fiber with a diameter of 180 μm, which can be applied to micro-cable products with a smaller outer diameter.

[0040] The thin single-mode optical fiber has a fiber type of G.657.A1 and good macro-bending performance; at the same time, the mode field diameter of the thin single-mode optical fiber at a wavelength of 1310 nm is 9 μm, which is fully compatible with the commonly used G.652.D single-mode optical fiber in the market.

[0041] The diameter parameters of the G.652.D single-mode optical fiber include the core diameter, the cladding diameter and the coating diameter. The core diameter of the G.652.D single-mode optical fiber is 9.2±0.4 μm and 10.4±0.5 μm at wavelengths of 1310 nm and 1550 nm respectively, the cladding diameter is 125.0±1.0 μm, and the coating diameter is 245±7 μm.

[0042] The diameter of the core layer 1 of the present application is 8.5-9.5 μm, and the diameter of the core layer 1 is further preferably 9 μm. The diameter of the inner cladding layer 2 is 124.3-125.7 μm, and the diameter of the inner cladding layer 2 is further preferably 125 μm. The geometric dimensions of the core layer 1 and the inner cladding layer 2 of the present application are similar to the core diameter and the cladding diameter of the G.652.D single-mode optical fiber, and can be normally fused with the G.652.D single-mode optical fiber.

[0043] The one-way fusion loss of the thin single-mode optical fiber of the present application and the commonly used G.652.D single-mode optical fiber in the market is less than 0.1 dB, and the two-way average fusion loss of the thin single-mode optical fiber and the G.652.D single-mode optical fiber is less than 0.05 dB, which is more conducive to market sales and engineering application.

[0044] The inner coating layer 3 and the outer coating layer 4 are both preferably acrylic resin materials. The acrylic resin not only provides excellent mechanical protection and environmental corrosion resistance, but also improves production efficiency through rapid ultraviolet curing, while maintaining high flexibility and transparency to support stable transmission of optical signals.

[0045] The low moisture absorption property of the acrylic resin material effectively prevents performance degradation, protects the core layer 1 from mechanical damage and environmental impact, and ensures reliable operation of the core layer 1 under bending and complex conditions.

[0046] The inner coating layer 3 is preferably a soft acrylic resin for absorbing mechanical stress and reducing micro-bending loss; the outer coating layer 4 is preferably a hard acrylic resin for enhancing mechanical strength and wear resistance.

[0047] In some optional embodiments, referring to Figure 1As shown in the drawings, the first aspect of the embodiment of the present application provides a large-mode-field thin single-mode optical fiber, the inner coating 3 of the thin single-mode optical fiber has an elastic modulus of 0.2-0.4 MPa, a breaking strength of ≥30 MPa, an elongation at break of ≥20%, and a Tg≤-20℃.

[0048] To obtain better anti-macro-bending and micro-bending performance, the elastic modulus of the inner coating 3 needs to be appropriately reduced, and the elastic modulus of the inner coating is 0.2-0.4 MPa, thereby playing a better buffering effect to offset the negative effects caused by the reduction of the coating thickness.

[0049] The anti-cutting surface stress capability of the inner coating 3 needs to be enhanced, and the adhesion to the optical fiber and the breaking strength of the inner coating 3 need to be improved, the breaking strength of the inner coating 3 is ≥30 MPa, and the elongation at break of the inner coating 3 is ≥20%.

[0050] To ensure good low-temperature performance of the optical fiber, the Tg of the inner coating 3 needs to be appropriately reduced to ensure better stress buffering at low temperatures, and the Tg of the inner coating 3 is ≤-20℃.

[0051] To ensure that the optical fiber is not crushed during drawing and screening, the elastic modulus of the outer coating 4 is 700-1000 MPa, the Tg is ≤90℃, and the thermal expansion coefficient of the outer coating 4 needs to better match the inner coating 3 to prevent additional stress on the optical fiber during the shrinkage process, and the expansion coefficient of the outer coating 4 is 70-130 K.

[0052] In some optional embodiments, referring to Figure 1 As shown in the drawings, the first aspect of the embodiment of the present application provides a large-mode-field thin single-mode optical fiber, the water permeability of the thin single-mode optical fiber is 20-50 g / (m 2 .day).

[0053] To ensure the water resistance and moisture heat aging resistance of the thin single-mode optical fiber, the water permeability of the coating needs to be reduced after the thickness of the inner coating 3 and the outer coating 4 is reduced, thereby reducing the erosion of water vapor on the optical fiber, and the water permeability is 20-50 g / (m2.day).

[0054] In some optional embodiments, referring to Figure 1 As shown in the drawings, the first aspect of the embodiment of the present application provides a large-mode-field thin single-mode optical fiber, the macro-bending performance of the thin single-mode optical fiber meets the following conditions: 1 turn of bending with a diameter of 20 mm, the macro-bending loss at a wavelength of 1550 nm is ≤0.5 dB, and the macro-bending loss at a wavelength of 1625 nm is ≤1.5 dB; 10 turns of bending with a diameter of 30 mm, the macro-bending loss at a wavelength of 1550 nm is ≤0.15 dB, and the macro-bending loss at a wavelength of 1625 nm is ≤0.5 dB.

[0055] In some optional embodiments, referring toFigure 1 As shown, the first aspect of the embodiment of the present application provides a large-mode-field thin-diameter single-mode optical fiber, which has an additional attenuation of ≤0.03 dB / km at a working wavelength of 1310 nm, 1383 nm, 1550 nm, and 1625 nm in a temperature environment of -60 ℃ to 85 ℃, so that the thin-diameter single-mode optical fiber has good environmental performance.

[0056] The average peeling force of the inner coating 3 and the outer coating 4 of the thin-diameter single-mode optical fiber is greater than 1 N, and the average peeling force of the inner coating 3 and the outer coating 4 is still greater than 1 N after 30 days of water immersion or hydrothermal aging experiment.

[0057] The second aspect of the embodiment of the present application provides a micro optical cable, which comprises the thin-diameter single-mode optical fiber of any one of the above embodiments. The micro optical cable is provided with 96 thin-diameter single-mode optical fibers, and the outer diameter of the micro optical cable is 4.7 mm; or the micro optical cable is provided with 144 thin-diameter single-mode optical fibers, and the outer diameter of the micro optical cable is 5 mm. The cable accessory attenuation is less than 0.01 dB / km. At the same time, the optical cable test requirements such as additional attenuation of ≤0.1 dB / km in the process of -30 to 70 ℃ temperature cycle and 700 N tensile accessory attenuation of ≤0.1 dB / km are met.

[0058] The embodiment of the present application provides a large-mode-field thin-diameter single-mode optical fiber and a micro optical cable. The large-mode-field thin-diameter single-mode optical fiber of the present application is provided with a core layer 1, the diameter of the core layer 1 is 8.5 to 9.5 μm; an inner cladding layer 2, the inner cladding layer 2 is coated on the outer periphery of the core layer 1, the diameter of the inner cladding layer 2 is 124.3 to 125.7 μm; an inner coating layer 3, the inner coating layer 3 is coated on the outer periphery of the inner cladding layer 2, the diameter of the inner coating layer 3 is 140 to 150 μm; and an outer coating layer 4, the outer coating layer 4 is coated on the outer periphery of the inner coating layer 3, the diameter of the outer coating layer 4 is 175 to 185 μm.

[0059] Therefore, the core layer 1, the inner cladding layer 2, the inner coating layer 3, and the outer coating layer 4 of the large-mode-field thin-diameter single-mode optical fiber of the present application together form a thin-diameter single-mode optical fiber with a diameter of 180 μm, and the thin-diameter single-mode optical fiber can be applied to micro cable products with smaller outer diameter. The thin-diameter single-mode optical fiber has a fiber type of G.657.A1 and has good macro-bending performance. At the same time, the thin-diameter single-mode optical fiber has a mode field diameter of 9 μm at a wavelength of 1310 nm, which is completely compatible with the commonly used G.652.D single-mode optical fiber in the market, and the one-way fusion splicing loss of the thin-diameter single-mode optical fiber and the G.652.D single-mode optical fiber is less than 0.1 dB, which is more conducive to market sales and engineering application.

[0060] In the description of the present application, it should be noted that the terms "upper", "lower", and the like are used for indicating 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", "connection", "connecting" should be interpreted broadly, for example, can be fixed connection, can also be detachable connection, or integrally connected; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be the internal communication of 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.

[0061] 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 "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus including a series of elements includes not only those elements, but also other elements not explicitly listed, or other elements inherent in such a process, method, article or apparatus. Without more limitations, the element defined by the statement "comprising a" does not exclude the presence of other identical elements in the process, method, article or apparatus including the element.

[0062] 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 to 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. A large mode field, small diameter single mode optical fiber, characterized by, It comprises: a core layer (1) with a diameter of 8.5-9.5 μm; an inner cladding layer (2) coated on the outer periphery of the core layer (1), the inner cladding layer (2) having a diameter of 124.3-125.7 μm; an inner coating layer (3) coated on the outer periphery of the inner cladding layer (2), the inner coating layer (3) having a diameter of 140-150 μm; an outer coating layer (4) coated on the outer periphery of the inner coating layer (3), the outer coating layer (4) having a diameter of 175-185 μm.

2. The large-mode-field thin single-mode optical fiber according to claim 1, wherein the mode field diameter of the thin single-mode optical fiber at a wavelength of 1310 nm is 8.8-9.6 μm.

3. The large-mode-field thin single-mode optical fiber according to claim 1 or 2, wherein the mode field diameter of the thin single-mode optical fiber at a wavelength of 1310 nm is 9 μm.

4. The large-mode-field thin single-mode optical fiber according to claim 1, wherein the inner coating layer (3) has an elastic modulus of 0.2-0.4 MPa, a breaking strength ≥ 30 MPa, an elongation at break ≥ 20%, and a Tg ≤ -20 ℃; and the outer coating layer (4) has an elastic modulus of 700-1000 MPa, a Tg ≤ 90 ℃, and an expansion coefficient of 70-130 K.

5. The large-mode-field thin single-mode optical fiber according to claim 1, wherein the inner coating layer (3) has a thickness of 10-20 μm.

6. The large-mode-field thin single-mode optical fiber according to claim 1, wherein the thin single-mode optical fiber has a macrobending performance satisfying that, when bent at a diameter of 20 mm for one turn, the macrobending loss at a wavelength of 1550 nm is ≤ 0.5 dB, and the macrobending loss at a wavelength of 1625 nm is ≤ 1.5 dB; and when bent at a diameter of 30 mm for 10 turns, the macrobending loss at a wavelength of 1550 nm is ≤ 0.15 dB, and the macrobending loss at a wavelength of 1625 nm is ≤ 0.5 dB.

7. The large-mode-field thin single-mode optical fiber according to claim 1, wherein the thin single-mode optical fiber has an additional attenuation of ≤ 0.03 dB / km at a working wavelength of 1310 nm, 1383 nm, 1550 nm, and 1625 nm in a temperature environment of -60 ℃-85 ℃.

8. The large-mode-field thin single-mode optical fiber according to claim 1, wherein the average peeling force of the inner coating layer (3) and the outer coating layer (4) of the thin single-mode optical fiber is greater than 1 N.

9. A micro optical cable, comprising the thin single-mode optical fiber according to any one of claims 1-8. The fine-mode optical fiber has a water permeability ranging from 20 to 50 g / (m 2 .day).

10. The micro optical cable according to claim 9, wherein the micro optical cable contains 96 thin single-mode optical fibers, and has an outer diameter of 4.7 mm; or the micro optical cable contains 144 thin single-mode optical fibers, and has an outer diameter of 5 mm. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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