Step ultralow-attenuation dual-mode optical fiber

Abstract

The invention relates to a step ultralow-attenuation dual-mode optical fiber comprising a core layer and a cladding layer. The core layer has a radius R1 from 4.5 to 14 micrometers and a relative refractive index difference [delta]1 from -0.05% to 0.15%, and is successively wrapped in, from inside to outside, an inner cladding layer, a recessed inner cladding layer, an auxiliary outer cladding layer and the outer cladding layer. The inner cladding layer has a radius R2 from 9 to 18 micrometers, and a relative refractive index difference [delta]2 from -0.4% to -0.15%. The inner cladding layer has a radius R3 from 14 to 23 micrometers and a relative refractive index difference [delta]3 from -0.8% to -0.3%. The auxiliary outer cladding layer has a radius R4 from 37 to 50 micrometers and a relative refractive index difference [delta]4 from -0.6% to -0.25%. The outer cladding layer is a pure silica glass layer. The optical fiber supports the propagation of two LP modes including LP01 and LP11 on the C-band. The optical fiber can support long-distance signal transmission in two modes, and each mode has a low attenuation coefficient. The optical fiber is low in manufacturing cost, and thecomprehensive performances such as bending loss and dispersion of the optical fiber is at a good level in the stress band.

Description

technical field [0001] The invention relates to a few-mode optical fiber used in an optical fiber communication system, in particular to a step-type ultra-low attenuation two-mode optical fiber. Background technique [0002] Single-mode optical fibers are widely used in optical fiber communication networks due to their advantages such as fast transmission rate, large information carrying capacity, and long transmission distance. In recent years, with the increasing demand for capacity of communication and big data services, the network bandwidth has rapidly expanded, and the capacity of optical transmission networks is gradually approaching the Shannon limit of a single optical fiber: 100Tb / s. Space-division multiplexing and mode-division multiplexing technologies can break the traditional Shannon limit and achieve higher bandwidth transmission, which is the best way to solve the problem of transmission capacity. The fibers that support this multiplexing technology are mult...

AI Technical Summary

Problems solved by technology

In this way, the viscosity of the core layer of the pure silicon core is relatively high, and at the same time, the viscosity of the inner cladding layer doped with a large amount of F is relatively low, which will cause an imbalance in the viscosity matching of the fiber structure, so that the virtual temperature of the fiber will increase rapidly, resulting in the R of the fiber. d Increase

This not only offsets the benefits brought by the reduction of doping, but also may cause the fiber attenuation reverse anomaly

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