Optical fiber mode revolver, full-fiber mode multiplexer and demultiplexer

Abstract

The invention discloses an optical fiber mode revolver, a full-fiber mode multiplexer and a demultiplexer. The optical fiber mode revolver comprises two inner cores which are symmetrically distributed, and the distances between the fiber core of the optical fiber and the two inner cores are preset distances; the angle between the connection line between the inner cores and the optical axis of the guided mode is the preset angle; the refractive index of the fiber core and the refractive indexes of two inner cores are different; the length of the optical fiber mode revolver is the beat length of two propagation constants of two guided modes which realize the mode conversion. Because the two inner cores are symmetrically arranged on two sides of the fiber core of the optical fiber, the refractive index of the inner core is different from that of the fiber core, and the incident guided mode can be rotated for 90 degrees. As a result, the mode conversion can be realized on the basis of the optical fiber, and the reusing of the mode can be realized. Besides, the mode revolver is based on the optical fiber, which prevents the insertion loss and effectively improves the performance of the communication system.

Description

technical field [0001] The invention relates to the technical field of optical communication, in particular to an optical fiber mode rotator, an all-fiber mode multiplexer and a demultiplexer. Background technique [0002] With the continuous evolution of communication technology and the emergence of new services, people have higher and higher requirements on the capacity of communication networks. In the past ten years, in order to improve the capacity of optical fiber communication, researchers have developed many advanced technologies based on single-mode optical fiber, for example, using high-order quadrature modulation format instead of simple amplitude modulation format, polarization multiplexing (PDM), Dense Wavelength Division Multiplexing (DWDM) technology, Orthogonal Frequency Division Multiplexing (OFDM) technology, etc., make the current single-mode fiber capacity close to Shannon's limit. In this case, people began to turn their attention to multimode fiber aga...

AI Technical Summary

Problems solved by technology

Although these mode multiplexers/demultiplexers can achieve mode multiplexing/demultiplexing, their insertion loss and mode crosstalk are very serious

This is because in order to realize the multiplexing of degenerate modes, it is necessary to set the mode multiplexers on the same plane at different angles of the few-mode fiber, and the technology based on optical fiber devices in the prior art cannot

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