The optical grating fiber sensing technology be used in geological hazards monitoring

摘要

The wavelength demodulation for fiber Bragg grating uses the property that the fiber grating's average refractive index and grid cycle are sensitive to the environment parameters, and to convert environmental parameters' change into a shift of the Bragg wavelength. The environment parameters can be measured through demodulating the shift of Bragg wavelength. This paper introduces the principle of FBG, and using the wavelength demodulation technology to design a wavelength demodulation instrument, and then discusses the mounting craft of the optical fiber sensor and how to eliminate temperature influence in the strain wavelength. Finally gives some application examples about geo-hazard monitoring. As a result, it is suited that the optical fiber sensing technology be used in the strain monitoring.