A low-attenuation multi-mode fiber

Abstract

The invention relates to a low-attenuation few-mode fiber. The low-attenuation few-mode fiber is that two core layers are provided; three wrapping layers ware arranged at the outsides of the core layers from inside to outside; the relative refractive rate difference delta 1 of the first core layer is 0.30 to 0.42%, and the radius R1 is 5.4 to 8 microns; the relative refractive rate difference delta 2 of the second core layer is 0.20 to 0.25%, and the radius R2 is 10 to 13 microns; the first wrapping layer is an inner wrapping layer which is closely arranged around the core layers, the relative refractive rate difference delta 4 is -0.02 to 0.02%, and the radius R4 is 13.6 to 17 microns; the second wrapping layer is a sunken wrapping layer which is arranged closely around the inner wrapping layers, the relative refractive rate difference delta 5 is -0.8 to 0.4%, and the radius R5 is 17.5 to 30 microns; the third wrapping layer is an outer wrapping layer which is arranged closely around the sunken wrapping layer and is a pure quartz glass layer. The low-attenuation few-mode fiber supports four stable transmission modes under 1550nm, is relatively small in DGD, simple in process, convenient to manufacture, relatively low in attenuation and relatively high in bending resistance.

Description

technical field [0001] The invention relates to a low-attenuation reduced-mode optical fiber used in an optical fiber communication system. The fiber core of the optical fiber has a stepped cross-section structure, and the four modes supported by it in the 1550nm communication band have lower differential mode group delay (DGD) , lower attenuation and better bending resistance, belonging to the technical field of optical fiber communication. 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 mo...

AI Technical Summary

Problems solved by technology

The few-mode fiber with parabolic profile has more adjustable parameters, so that the intermode crosstalk and DGD can reach a very low level, but its preparation process is complicated, and the alpha parameter is difficult to control accurately and uniformly, and the repeatability is not high.

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