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CN-122018075-A - Ultralow attenuation coupling weakening multi-core optical fiber, manufacturing method thereof and multi-core optical cable

CN122018075ACN 122018075 ACN122018075 ACN 122018075ACN-122018075-A

Abstract

The invention belongs to the technical field of optical fiber communication, and discloses an ultralow-attenuation coupling-weakening multi-core optical fiber, a manufacturing method thereof and a multi-core optical cable. The ultra-low attenuation coupling-weakening multi-core optical fiber comprises a common outer cladding layer and a plurality of fiber cores arranged in the common outer cladding layer, wherein each fiber core sequentially comprises a core layer, an inner cladding layer and a sunken layer from inside to outside, the material of the core layer is germanium-fluorine co-doped silica, the influence of doping on the viscosity of the core layer is defined as delta eta 1, the material of the inner cladding layer is germanium-fluorine co-doped silica, the influence of doping on the viscosity of the inner cladding layer is defined as delta eta 2, the material of the sunken layer is singly fluorine-doped silica or germanium-fluorine co-doped silica, the influence of doping on the viscosity of the sunken layer is defined as delta eta 3, and the conditions of delta eta 1, delta eta 1 and delta eta 2 and delta eta 3 are simultaneously satisfied that 1.1 delta eta 2< delta eta 1<0.9 delta eta 2 and delta eta 3>3 delta eta 2. The invention can greatly reduce the attenuation of the weakly coupled multi-core optical fiber.

Inventors

  • YANG LIUBO
  • ZHANG LEI
  • SHEN LEI
  • XU SHUO
  • LUO JIE

Assignees

  • 长飞光纤光缆股份有限公司

Dates

Publication Date
20260512
Application Date
20260127

Claims (10)

  1. 1. The ultra-low attenuation weakly coupled multi-core optical fiber is characterized by comprising a common outer cladding and a plurality of fiber cores arranged in the common outer cladding, wherein each fiber core comprises a core layer, an inner cladding layer and a sunken layer from inside to outside in sequence; The material of the core layer is germanium-fluorine co-doped silicon dioxide, and the influence of doping on the viscosity of the core layer is defined as delta eta 1; the material of the inner cladding is silicon dioxide co-doped with germanium and fluorine, and the influence of doping on the viscosity of the inner cladding is defined as delta eta 2; The material of the sinking layer is silicon dioxide doped with fluorine singly or silicon dioxide doped with germanium and fluorine together, and the influence of doping on the viscosity of the sinking layer is defined as delta eta 3; Δη1, Δη2, Δη3 satisfy 1.1Δη2< Δη1<0.9Δη2, Δη 3>3 Δη2 at the same time.
  2. 2. The ultra-low attenuation weakly coupled multicore fiber of claim 1, wherein the effect Δη1 of doping on core viscosity is expressed as Δη1= - Δge1+3Δf1, Δge1 being the effect of germanium in the core on refractive index and Δf1 being the effect of fluorine in the core on refractive index; The effect of the doping on the viscosity of the inner cladding is expressed as Deltaeta 2= -DeltaGe2+3DeltaF2, deltaGe2 is the effect of germanium in the inner cladding on the refractive index, deltaF 2 is the effect of fluorine in the inner cladding on the refractive index; The effect of doping on the viscosity of the depressed layer Δη3 is expressed as Δη3= - Δge3+3Δf3, Δge3 being the effect of germanium in the depressed layer on the refractive index and Δf3 being the effect of fluorine in the depressed layer on the refractive index.
  3. 3. The ultra-low attenuation weakly coupled multicore fiber of claim 1, wherein a plurality of the cores are equally distributed in the circumferential direction, the number of the cores is greater than 2, and the distance between adjacent cores is P, P >30 μm.
  4. 4. The ultra-low attenuation weakly coupled multicore fiber of claim 1, wherein the core has a radius r1 ranging from 3 μm to 6 μm, the inner cladding has a radius r2 ranging from 6 μm to 10 μm and r2> r1, and the depressed layer has a radius r3 ranging from 10 μm to 13 μm and r3> r2.
  5. 5. The ultra-low attenuation, weakly coupled multi-core fiber of claim 1, wherein the optical waveguide is weakly coupled between the individual cores of the ultra-low attenuation, weakly coupled multi-core fiber; In the O band, each core attenuation of the ultra-low attenuation weakly coupled multi-core optical fiber is less than 0.27dB/km; in the C wave band, each core attenuation of the ultra-low attenuation weak coupling multi-core optical fiber is less than 0.175dB/km; In the L band, each core attenuation of the ultra-low attenuation weakly coupled multi-core fiber is less than 0.19dB/km.
  6. 6. The ultra-low attenuation, weakly coupled multi-core fiber of claim 1, wherein the macrobend loss of each core of the ultra-low attenuation, weakly coupled multi-core fiber is less than or equal to 0.1dB at R30mm bend radii for the O-, C-, and L-bands.
  7. 7. The ultra-low attenuation, weakly coupled multi-core fiber of claim 1 having fusion loss of each core less than or equal to 0.2dB in the O-, C-and L-bands.
  8. 8. A method of manufacturing an ultra-low attenuation coupling multicore fiber according to any of claims 1 to 7, comprising the steps of: Preparing a plurality of homogeneous core rods by adopting a plasma chemical vapor deposition process; sleeving a plurality of homogeneous core rods and the multi-core sleeve to obtain a weakly-coupled multi-core optical fiber preform; Drawing the weakly coupled multi-core optical fiber preform rod to obtain an ultralow attenuation weakly coupled multi-core optical fiber; the ultra-low attenuation coupling multi-core optical fiber simultaneously satisfies 1.1 delta eta 2< delta eta 1<0.9 delta eta 2, delta eta 3>3 delta eta 2, delta eta 1 is the influence of doping on the viscosity of a core layer, delta eta 2 is the influence of doping on the viscosity of an inner cladding layer, and delta eta 3 is the influence of doping on the viscosity of a sinking layer.
  9. 9. A multicore cable comprising a first number n1 of loose tubes, each of said loose tubes having a second number n2 of the ultra-low attenuation coupling multicore fibers of any one of claims 1 to 7.
  10. 10. The multi-core optical cable of claim 9, wherein the multi-core optical cable comprises a number of channels of n1×n2×n3 when the number of cores in the ultra-low attenuation coupling multi-core optical fiber is n3.

Description

Ultralow attenuation coupling weakening multi-core optical fiber, manufacturing method thereof and multi-core optical cable Technical Field The invention belongs to the technical field of optical fiber communication, and particularly relates to an ultralow-attenuation weak-coupling multi-core optical fiber, a manufacturing method thereof and a multi-core optical cable. Background In recent years, with the rising of cloud computing, big data and mobile internet, a data center with efficient inter-server cooperation and data processing capability becomes an obvious information total amount and information density increasing hot spot, and urgent requirements are also provided for the improvement of the interconnection communication rate of the data center. Because the interconnection communication of the data center has the characteristics of numerous equipment, complex wiring, high interface density and the like, the cost, the power consumption, the complexity and the like of the operation or the maintenance of the system are increased by only increasing the modulation bandwidth of devices and increasing the number of optical fiber links or output light sources with different stable wavelengths, and therefore, the transmission rate of single optical fibers/wavelengths is increased under the condition of a new modulation/multiplexing mode, and the method is regarded as an effective solution for increasing the interconnection rate of the data center. In practical optical fiber systems, the high-order modulation and polarization multiplexing technology has limited capacity expansion due to factors such as system signal-to-noise ratio, optical fiber nonlinearity and the like, and has a great challenge for meeting the requirements of interconnection communication of next-generation data centers, such as 800G,1T and even 1.6T. Space Division Multiplexing (SDM) technology based on multi-core optical fibers or multi-mode optical fibers has larger expansion potential in the mode and space dimension of the optical fibers, and can be compatible with a high-order modulation format and a polarization multiplexing technology, so that the communication capacity of single optical fiber/wavelength can be greatly improved. In addition, for communication systems with higher power consumption requirements, more spatial channels are employed, and the communication capacity of each spatial channel can be relatively reduced. Therefore, by adopting the SDM technology of multiple spatial channels, a higher transmission capacity can be realized in theory per unit power consumption without increasing the number of optical fiber links. At present, in the preparation process of the optical fiber preform, the core layer, the inner cladding layer and the depressed layer are usually doped for changing the refractive index, but doping substances are introduced into pure silicon dioxide materials to cause the viscosity change of the materials, if the materials are not designed, the viscosity among the layers of the preform is definitely changed severely, and the difference of the viscosity can cause the internal stress of the core rod, so that the residual thermal stress and broken bonds in the optical fiber are caused in the subsequent process of manufacturing the optical fiber, and the attenuation of the optical fiber is increased. Disclosure of Invention The invention provides an ultralow attenuation coupling-weakening multi-core optical fiber, a manufacturing method thereof and a multi-core optical cable, which solve the problem of larger attenuation of a weak coupling multi-core optical fiber in the prior art. The invention provides an ultralow attenuation weakly-coupled multi-core optical fiber, which comprises a common outer cladding and a plurality of fiber cores arranged in the common outer cladding, wherein each fiber core comprises a core layer, an inner cladding layer and a sunken layer from inside to outside in sequence; The material of the core layer is germanium-fluorine co-doped silicon dioxide, and the influence of doping on the viscosity of the core layer is defined as delta eta 1; the material of the inner cladding is silicon dioxide co-doped with germanium and fluorine, and the influence of doping on the viscosity of the inner cladding is defined as delta eta 2; The material of the sinking layer is silicon dioxide doped with fluorine singly or silicon dioxide doped with germanium and fluorine together, and the influence of doping on the viscosity of the sinking layer is defined as delta eta 3; Δη1, Δη2, Δη3 satisfy 1.1Δη2< Δη1<0.9Δη2, Δη 3>3 Δη2 at the same time. Preferably, the effect Δη1 of the doping on the viscosity of the core layer is expressed as Δη1= - Δge1+3Δf1, Δge1 being the effect of germanium in the core layer on the refractive index and Δf1 being the effect of fluorine in the core layer on the refractive index; The effect of the doping on the viscosity of the inner cladding is expressed as Deltaeta 2= -DeltaG