Low Attenuation LMF

Abstract

The invention relates to a low-attenuation and few-mode fiber. A core layer has three layers and comprises three claddings from inside to outside; the relative refractive index difference delta 1 of a first core layer is 0.34%-0.45%, R1 ranges from 4.5 mu m to 7.5 mu m, the relative refractive index difference delta 2 of a second core layer is 0.20%-0.29%, R2ranges from8 mu m to 10 mu m, the relative refractive index difference delta 3 of a third core layer is 0.15%-0.24%, R3 ranges from 10 mu m to 13 mu m, the relative refractive index difference delta 4 of a first cladding is minus 0.02%-0.02%, R4 ranges from14 mu m to 18 mu m, the second cladding is a concave cladding, the relative refractive index difference delta 5 of the second cladding is minus 0.8%-minus 0.4%, R5 ranges from19 mu m to 31 mu m, and a third cladding is a pure quartz glass layer. According to the low-attenuation and few-mode fiber, four stable transmission modes are supported within 1550 nm, small DGD is provided, the process is simple, and the manufacturing is easy; at the same time, the low-attenuation and few-mode fiber has low attenuation and better 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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