Low-attenuation bending insensitive single mode fiber

Abstract

The invention relates to a low-attenuation bending insensitive single mode fiber which comprises a core layer and wrapping layers. The low-attenuation bending insensitive single mode fiber is characterized in that the relative refractive index difference delta1 of the core layer ranges from 0.30% to 0.38%, the radius R1 of the core layer ranges from 3.5 micrometers to 4.5 micrometers, the four wrapping layers are arranged outside the core layer, the first wrapping layer is a first inner wrapping layer tightly surrounding the core layer, the relative refractive index difference delta2 of the first wrapping layer ranges from -0.02% to 0.02%, the radius R2 of the first wrapping layer ranges from 6.5 micrometers to 8.5 micrometers, the second wrapping layer is a second inner wrapping layer tightly surrounding the first inner wrapping layer, the relative refractive index difference delta3 of the second wrapping layer ranges from -0.02% to 0.02%, the radius R3 of the second wrapping layer ranges from 8 micrometers to 11 micrometers, the third wrapping layer is a downwards-concave wrapping layer tightly surrounding the second inner wrapping layer, the relative refractive index difference delta4 of the third wrapping layer ranges from -0.5% to -0.2%, the radius R4 of the third wrapping layer ranges from 12 micrometers to 20 micrometers, and the fourth wrapping layer is an outer wrapping layer tightly surrounding the downwards-concave wrapping layer and is a pure quartz glass layer. The low-attenuation bending insensitive single mode fiber can be completely matched with a G.652.D optical fiber, and therefore the low attenuation, the large effective area and the bending resistance can be better unified.

Description

technical field [0001] The invention relates to a single-mode optical fiber used in an optical fiber communication system. The optical fiber has a mode field diameter that completely matches G.652.D, better bending resistance and lower attenuation than G.657.A1, and belongs to optical fiber communication technology field. Background technique [0002] Single-mode optical fiber is widely used in optical fiber communication networks due to its fast transmission rate, large information carrying capacity, and long transmission distance. Among them, the optical fiber that meets the ITU-T G.652 standard is the most used single-mode optical fiber. Optical fibers are widely used in backbone networks and metropolitan area networks. With the continuous development of FTTX in recent years, the performance of the original G.652 optical fiber can no longer meet the requirements of users. The actual application environment requires the optical fiber to have a certain bending resistance. ...

AI Technical Summary

Problems solved by technology

However, the reduction of the mode field diameter will result in a reduction of the effective area, and it is easy to cause more defects and increase the attenuation during wire drawing. At the same time, the cut-off wavelength of the fiber must be smaller than the working wavelength to ensure the single-mode working characteristics, so by There is limited space to change the MAC value of the fiber to improve the bending performance of the fiber

The second is that the bending performance can be improved by using a double-clad structure in which the inner cladding is a depressed cladding, but the depressed cladding may cause the "LP01 mode leakage" phenomenon of the optical fiber

Due to the large amount of doping, the viscosity of the core layer is very small, so that the optical fiber is easily subjected to tensile stress under the action of drawing tension, which causes the distortion of the fiber core layer section, and also makes the stress distribution gradient of the optical fiber in the bent state larger. , thus affecting the bending resistance

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