Sensing multiplexing system based on non-equidistant weak Bragg reflection fiber Bragg grating array

Abstract

The invention discloses a sensing multiplexing system based on a non-equidistant weak Bragg reflection fiber Bragg grating array. The system comprises a tunable laser (T), a modulator (E), an optical isolator (I), an optical circulator (C) and a wavelength demodulation device (D) which are connected in turn, wherein the optical circulator (C) is connected to a sensing optical fiber with a plurality of fiber Bragg gratings. The interference effect caused by multiple reflection among the fiber Bragg gratings can be avoided, the multiplexing capacity of the system can be greatly improved, and long-distance high-density high-capacity distributed detection is realized.

Description

technical field [0001] The invention relates to the field of sensing technology, in particular to a sensing multiplexing method based on non-equally spaced weak Bragg reflection fiber grating arrays. Background technique [0002] FBG (Fiber Bragg Grating) sensing is characterized by central wavelength encoding, and the change of external parameters can be measured by monitoring the movement of the FBG central wavelength, and the detection signal is not affected by the power fluctuation of the light source. However, a major problem faced by FBG-based distributed sensing is that the multiplexing capacity of the system is limited by the bandwidth of the light source and filter. [0003] There have been reports of multiple multiplexing methods, such as space division multiplexing, time division multiplexing, wavelength division multiplexing, subcarrier multiplexing, frequency modulation continuous wave multiplexing, etc., and combinations of these multiplexing methods. There ar...

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Problems solved by technology

However, a major problem faced by FBG-based distributed sensing is that the multiplexing capacity of the system is limited by the bandwidth of the light source and filter.

[0003] There have been reports of multiple multiplexing methods, such as space division multiplexing, time division multiplexing, wavelength division multiplexing, subcarrier multiplexing, frequency modulation continuous wave multiplexing, etc., and combinations of these multiplexing methods. It has its own characteristics, but none of them can solve factors such as multiplexing, cost, and practicality well, and it is far from enough for long-distance and high-density distributed detection

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