Ultralow attenuation single-mode optical fiber

Abstract

The invention relates to an ultralow attenuation single-mode optical fiber, and the optical fiber comprises a core layer and a cladding layer. The optical fiber is characterized in that the radius r1 of the core layer is 3-5 microns; the relative refractive index delta n1 of the core layer is 0-0.20%; the exterior of the core layer is sequentially wrapped by an internal cladding layer, a recessed internal cladding layer and an external cladding layer from the inside to the outside; the radius r2 of the internal cladding layer is 6-10 microns, and the relative refractive index delta n2 is less than or equal to -0.23%; the radius r3 of the recessed internal cladding layer is 10.5-20 microns, and the relative refractive index delta n3 is less than or equal to -0.40%; the external cladding layer is a full fluorine-doped silicon dioxide glass layer, and the relative refractive index delta n4 is less than or equal to -0.23%. According to the invention, the core layer and the cladding layers are designed to be made of different materials, thereby optimizing the viscosity and optical fiber stress of each part of the optical fiber, reducing the mismatching of the structure relaxation time of the glass materials of the core layer and the internal cladding layer in a preparation process of the optical fiber, and reducing the interface defects. Moreover, the core layer is doped with an alkali metal, thereby effectively reducing the virtual temperature of the core layer, and achieving the ultralow attenuation performance of the single-mode optical fiber.

Description

technical field [0001] The invention relates to the field of optical communication, in particular to an ultra-low attenuation single-mode optical fiber. Background technique [0002] At present, the hot spot in the field of optical fiber manufacturing is the preparation of new ultra-low attenuation single-mode optical fiber products, so finding an effective method to reduce the attenuation coefficient of optical fiber and control manufacturing costs is a huge challenge for optical fiber manufacturing enterprises. The main difficulty lies in the following three points: First, how to reduce the attenuation: the main method at present is to reduce the Rayleigh scattering coefficient of the optical fiber; second, while obtaining an ultra-low attenuation coefficient, it is necessary to ensure that the optical parameters of the optical fiber meet the requirements of the ITU-T The standard mainly refers to the control of MFD, dispersion, cut-off wavelength and bending performance w...

AI Technical Summary

Problems solved by technology

The cross-sectional structure design and manufacturing process are quite complicated, and there are many factors that affect the fiber parameters, especially the dispersion of the fiber is difficult to control, and the fiber described in the article does not involve the dispersion coefficient of the fiber in each band and the microbending performance of the fiber

And because it adopts the concept of double outer cladding, at the interface of pure silica outer cladding and fluorine-doped outer cladding, in the process of drawing or manufacturing, it is inevitable to dope interface defects, which will affect the reduction of optical fiber attenuation performance

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