Fiber bragg grating array sensing method, device and system based on distributed feedback laser array

Abstract

The invention discloses a fiber bragg grating array sensing method based on a distributed feedback laser array, and the method measures the physical quantity change of a to-be-measured object througha fiber bragg grating array coupled to the to-be-measured object, and constructs a quasi-distributed physical quantity measurement system based on the distributed feedback laser array and the fiber bragg grating array. And a spectrum of the grating array is obtained by adopting an equal optical frequency interval sampling mode, so that wavelength demodulation and quasi-distributed physical quantity measurement of the fiber grating array are realized. A large-range access bandwidth is obtained, so that more fiber gratings can be multiplexed, and the measurement range of a physical quantity which can be detected by a single fiber grating is increased. The invention further discloses a corresponding device and system.

Description

technical field [0001] The invention belongs to the technical field of optical fiber sensing, and in particular relates to a fiber grating array sensing method, device and system based on a distributed feedback laser array. Background technique [0002] A fiber grating array is a fiber sensor that writes fiber gratings one by one on an optical fiber. Each fiber grating usually has a strong reflectivity, and the center wavelength is different. Since the fiber gratings on the sensor are distributed at discrete positions in space, the fiber grating array with this form is a quasi-distributed fiber sensor. The sensor is generally located at the measured object when in use, and can sense physical quantities such as temperature or strain at different positions of the measured object. The change of physical quantity will cause the central wavelength of the grating to shift. There are many demodulation methods for fiber grating arrays for sensing, including FP filter method, tunab...

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Problems solved by technology

However, the tuning range of this method is limited (the tuning range of the DBR laser is about 15nm) and because it is a step-by-step scan, the original sampling point of the spectrum is also a step amount of 1pm, which limits the resolution of the original spectrum and also limits the resolution of the measured physical quantity. force

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