Groove-assisted double-step ring core optical fiber

Abstract

The invention discloses a groove-assisted double-step ring core optical fiber. The groove-assisted double-step ring core optical fiber comprises a ring core and an outer cladding; the ring core sequentially comprises a central cladding, a second-layer step ring, a first-layer step ring and an annular groove from inside to outside; refractive indexes of the first-layer step ring core and the second-layer step ring core are distributed in a double-step ring core shape; the first-layer step ring core is used for controlling optical fiber normalization frequency so as to regulate and control the number of modes; the second-layer step ring core is used for increasing the effective area of the modes so as to reduce the nonlinear coefficient of each mode of the optical fiber and suppress a radialhigh-order mode; and the double-layer step structure is used for mode regulation and control with higher degree of freedom. The optical fiber can support eight-order OAM modules, the effective refractive index difference between the modules is larger than 10<-4>, and module weak coupling transmission can be adopted. Four modes in the modules are in a degenerate state, and a fixed 4*4-scale MIMO algorithm can be used. OAM modes supported by the optical fiber are all radial first-order modes.

Description

technical field [0001] The invention belongs to the field of optical fiber communication, and relates to a groove-assisted double-step ring-core optical fiber supporting multiple orbital angular momentum modes. Background technique [0002] The existing single-mode optical fiber communication technology has been developed for decades, and its capacity is close to the physical limit defined by Shannon's theorem. How to meet the continuously growing interconnection demand has become the core issue in the research of optical fiber communication technology. Time division, wavelength division, polarization division multiplexing technology and multi-level modulation make the capacity of single-mode fiber in large-capacity transmission systems quickly approach the Shannon theoretical limit. Space Division Multiplexing (SDM) technology can break through this limitation and provide a new solution for future growth of optical fiber capacity. [0003] In the space division multiplexi...

AI Technical Summary

Problems solved by technology

Excessive intrinsic crosstalk is a common pain point of ring-step fiber, which makes it difficult to apply to long-distance signal transmission

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