A fiber grating demodulator and demodulation method based on digitally tunable light source

Abstract

The invention provides a fiber bragg grating interrogator based on a digitization tunable light source. The fiber bragg grating interrogator based on the digitization tunable light source is characterized by comprising the digitization tunable light source, a coupler of a circulator, a photovoltaic conversion module, a data acquisition unit and a calculation and control unit, wherein wavelength and power of the digitization tunable light source are capable of being arbitrarily set, and the data acquisition unit is provided with synchronizing signals. Light emitted by the digitization tunable light source passes through the coupler or the circulator, enters a testing optical fiber, and is reflected by a fiber bragg grating on the testing optical fiber, and the light which carries tested information reversely passes through the coupler of the circulator and lights onto the photovoltaic conversion module. Signals of the light are collected by the synchronous data acquisition unit, and are sent into the calculation and control unit, reflected wavelength of the fiber bragg grating is calculated according to reflectivity of different wavelength, and information of temperature and strain of the fiber bragg grating to be tested is obtained. The fiber bragg grating interrogator based on the digitization tunable light source has the advantage of being capable of eliminating the synchronization problem of a traditional scanning type light resource caused by different distance of the fiber bragg grating.

Description

technical field [0001] The invention belongs to the technical fields of optical fiber sensing and optical measurement, and in particular relates to a fiber grating demodulator based on a digitally tunable light source. Background technique [0002] As a sensor with an intelligent structure, the fiber grating sensor has the advantages of small size, light weight, corrosion resistance, strong anti-electromagnetic interference, easy integration, simple structure, and high reliability. At the same time, it can also be applied in the fields of water conservancy and hydropower, coal mines, material industry, shipbuilding, chemical medicine, and can be embedded in concrete structures and components in the field of civil engineering to monitor the integrity and strain status of structures. In particular, its wavelength coding characteristics and the advantages of quasi-distributed measurement on a single optical fiber are unmatched by other sensors and have broad application prospec...

AI Technical Summary

Problems solved by technology

But the disadvantage is: during the AD sampling and holding time, the wavelength of the light source is still changing, and the measured result is the average wavelength, which is easy to cause test errors

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