A low-attenuation step-type orbital angular momentum optical fiber

Abstract

The invention discloses a stepped low-attenuation orbital angular momentum optical fiber. The stepped low-attenuation orbital angular momentum optical fiber comprises a core layer and a cladding layer, wherein the core layer has R1 of 3-5 microns and delta 1 of -0.08% to 0.08%; an annular core layer, a sunken cladding layer and an outer cladding layer sequentially coat the core layer from inside to outside; the annular core layer sequentially comprises an inner annular core layer, a sunken annular core layer and an outer annular core layer from inside to outside; the inner annular core layer has R2 of 4-6 microns and delta 2 of 0.7%-1%; the sunken annular core layer has R3 of 5-7 microns and delta 3 of 0.6%-0.9%; the outer annular core layer has R4 of 7-9 microns and delta 4 of 0.7%-1%, and delta 4 is equal to or basically equal to delta 2; the sunken cladding layer has R5 of 11-16 microns and delta 5 of -0.6% to -0.3%; the relative refractive index difference is a relative refractiveindex difference between each layer of the optical fiber and the outer cladding layer; and the outer cladding layer is an outer cladding layer with a negative refractive index relative to a pure silicon dioxide layer. According to the stepped low-attenuation orbital angular momentum optical fiber, the long-distance signal transmission of four mode groups can be supported; the attenuation is low; and the comprehensive performance of the crosstalk of the optical fiber, the macro-bending and micro-bending loss of each mode, and the like is good.

Description

technical field [0001] The invention relates to a space-division multiplexing transmission optical fiber used in an optical fiber communication system, in particular to a low-attenuation step-type orbital angular momentum (OAM) optical fiber. Background technique [0002] In recent years, with the rise of cloud computing, big data, and mobile Internet, data centers with efficient inter-server collaboration and data processing capabilities have become an obvious hotspot for the growth of information volume and information density, thus affecting the interconnection communication rate of data centers. urgent demands for improvement. Due to the characteristics of large number of devices, complex wiring, and high interface density in data center interconnection communication, relying only on improving device modulation bandwidth, increasing the number of optical fiber links or output light sources with different stable wavelengths will inevitably increase the cost of system oper...

AI Technical Summary

Problems solved by technology

In this way, the actual drawing and laying of defects in the core-cladding interface will have a more obvious impact on the coupling between modes, resulting in increased crosstalk and fiber attenuation

Chinese patent CN108680990A reports a ring-core orbital angular momentum optical fiber, but its attenuation is greater than 1dB / km, so it can only be used for short-distance transmission

Chinese patent CN106338793A reports that an RCF fiber can suppress some high-order modes that are easy to couple, but its attenuation is 0.31dB / km, which still has a certain gap with low-loss FMF

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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