Synchronous-sequence-based few-mode fiber mode-mode delay measurement system and method

Abstract

The invention discloses a synchronous-sequence-based few-mode fiber mode-mode delay measurement system and method, and relates to the field of optical communication. The method comprises the following steps: at a transmitting end, generating a group of synchronous sequences, modulating the synchronous sequences to optical carriers, dividing the synchronous sequences into N-path single-mode optical signals, performing different delays on the N-path single-mode optical signals, coupling the delayed N-path single-mode optical signals to form one-path N-mode multiplexed optical signals, and inputting the one-path N-mode multiplexed optical signals into a to-be-measured few-mode fiber; at a receiving end, demultiplexing the received one-path N-mode multiplexed optical signals so as to obtain N-path single-mode optical signals, and recovering synchronous sequence information of the N-path single-mode optical signals; by a digital signal processing module, determining relative start time positions of the received N-path synchronous sequences, comparing the determined relative start time positions of the received N-path synchronous sequences with the relative start time positions of the N-path synchronous sequences at the transmitting end so as to obtain a relative delay between any two modes, and by combining with the length of the to-be-measured few-mode fiber, computing an mode-mode delay parameter of the to-be-measured few-mode fiber between the any two modes. The synchronous-sequence-based few-mode fiber mode-mode delay measurement system and method have remarkably reduced costs and are suitable for future large-scale applications under engineering conditions.

Description

technical field [0001] The invention relates to the field of optical communication, in particular to a measurement system and method for intermode delay of a few-mode optical fiber based on a synchronous sequence. Background technique [0002] With the rapid development of the Internet, cloud computing, mobile broadband, and data centers, the demand for network transmission bandwidth has shown explosive growth, driving the development of ultra-large-capacity optical transmission systems. In order to increase the capacity of the existing optical transmission system, key technologies such as wavelength division multiplexing technology, digital coherent reception, and low-noise optical amplification are considered to be effective solutions to increase capacity. Since the introduction of wavelength division multiplexing technology into the field of optical fiber communication in the late 1980s, the single-fiber transmission capacity of single-mode optical fiber has increased exp...

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Problems solved by technology

The traditional few-mode optical fiber intermode delay measurement equipment adopts the pure optical principle. Although the measurem

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