Distributed optic fiber sensor based on multi-domain mixed and multiplex mode and modulation and demodulation method thereof

Abstract

The invention relates to a distributed optic fiber sensor based on a multi-domain mixed and multiplex mode and a modulation and demodulation method of the distributed optic fiber sensor. The optic fiber sensor comprises a data processing and controlling device (1), a light source module, an optical fiber sensing unit (13), a filter (4), a filter controlling module, a data collecting module and a light circulator (9). The data processing and controlling device (1) is respectively connected with the light source module, the filter controlling module and the data collecting module, the light circulator (9) is respectively connected with the light source module, the optical fiber sensing unit (13) and the filter (4), the filter controlling module is connected between the data processing and controlling device (1) and the filter (4), and the output end of the filter (4) is further connected with the input end of the data processing and controlling device (1) through the data collecting module. The distributed optic fiber sensor based on the multi-domain mixed and multiplex mode has the advantages of being large in capacity, low in cost, high in modulation and demodulation speed, compact in structure and the like and is suitable for large-scale and distributed sensing multiplexing.

Description

technical field [0001] The invention relates to the technical field of optical fiber sensing, and realizes large-capacity optical fiber sensing by expanding the multi-domain characteristics of optical signals in the optical fiber, and specially designs an embedded demodulation system for the sensing method. Background technique [0002] Optical fiber sensing is widely used in the monitoring of geological disasters, oceans, and large structures. Its anti-electromagnetic properties, compact structure, high sensing accuracy, and high scalability have attracted more and more attention. Because the demodulation system of fiber optic sensing is relatively expensive, increasing the number of single-fiber multiplexing can significantly reduce the demodulation cost of a single sensing node and expand its application field. [0003] U.S. Naval Research Laboratory T.A.Berkoff and others in the paper "HYBRID TIME AND WAVELENGTH DIVISION MULTIPLEXED FIBER BRAGG GRATING SENSOR ARRAY" Proc...

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Problems solved by technology

[0003] U.S. Naval Research Laboratory T.A.Berkoff and others in the paper "HYBRID TIME AND WAVELENGTH DIVISION MULTIPLEXED FIBER BRAGG GRATING SENSOR ARRAY" Proc. SPIE2444, Smart Structures and Materials1995: Smart Sensing, Processing, and Instrumentation, 288 (April20, 1995); doi: 10.1117 / 12.207684" put forward the concept of time division and wavelength division multiplexing, but its time division signal demodulation cannot achieve real-time performance, and the demodulation accuracy is too low to make frequency division multiplexing impossible

[0004] The application number is 201110420315.8, and the patent application titled "quasi-distributed sensor based on microstructure fiber Fabry-Perot resonator" proposes wavelength division and frequency division multiplexing, which uses a spectrum analyzer, which is expensive and can only To realize two-dimensional multiplexing, due to the long demodulation period of the spectrum analyzer, and the spectrum analyzer cannot provide an external control interface, TDM (time division multiplexing) multiplexing cannot be performed

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