Few-mode fiber mode coupling measurement device based on two-photon lantern and few-mode fiber circulator

Abstract

The invention provides a few-mode fiber mode coupling measurement device based on a two-photon lantern and a few-mode fiber circulator and belongs to the technical field of fiber characteristic measurement. The few-mode fiber mode coupling measurement device is composed of a light source, a photon lantern A, a few-mode fiber circulator, a measured fiber, a photon lantern B, a photoelectric detection module and a signal processing module. An optical pulse signal generated by the light source is subjected to spatial mode conversion through the photon lantern A to output a designated single stimulus mode, combined with the single-way transmission characteristics of the few-mode fiber circulator, the stimulus mode enters the measured fiber through the few-mode fiber circulator, a backward Rayleigh scattered light generated by coupling the stimulus mode in the measured fiber and the stimulus mode to the non-stimulus mode enters the photon lantern B through the few-mode fiber circulator for spatial model demultiplexing and being output from a corresponding mode port, and the output backward scattered light of each path is subjected to photoelectric detection and data processing, so that the measurement of the few-mode fiber mode coupling coefficient is achieved.

Description

technical field [0001] The invention belongs to the technical field of optical fiber characteristic measurement, in particular to a few-mode fiber mode coupling measurement device based on a two-photon lantern and a few-mode fiber circulator. Background technique [0002] With the rapid growth of global bandwidth-consuming services, the capacity of single-mode optical fiber systems approaches the Shannon limit. In order to break through the nonlinear "Shannon limit" of the single-mode optical fiber communication system capacity, Mode Division Multiplexing (MDM) technology performs mode multiplexing by mining the new spatial dimension of the mode, which greatly improves the capacity of the optical fiber communication system. . However, with the improvement of capacity and transmission rate, the tolerance of MDM system to various signal impairments decreases, which reduces the reliability of the system. Therefore, it is of great practical significance to carry out the resear...

AI Technical Summary

Problems solved by technology

However, the current mode-coupling measurement device based on Rayleigh scattering needs to use an optical isolator and an acousto-optic modulator to form an optical switch to eliminate the Fresnel reflection caused by the input end of the fiber, so as to reduce the dead zone and improve the dynamic range of the measurement. more complicated structure

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