Ultrahigh Resolution Fiber Bragg Grating Sensors for Quasi-Static Crustal Deformation Measurement

Recently developed ultrahigh resolution optical fiber grating sensors provide powerful tools for crustal deformation monitoring thanks to their unique advantages such as high resolution, low cost, easy deployment, and capability of remote and multiplexed sensing. This paper reviews the development of several types of fiber-optic sensors with ultrahigh resolution in quasi-static domain, including a fiber Bragg grating sensor interrogated with a narrow-linewidth wavelength-sweeping laser, a fiber grating based Fabry-Perot interferometer sensor by using Pound-Drever-Hall technique, sensors interrogated with sideband interrogation method, and the realization of time division multiplexed ultrahigh resolution fiber sensors. The implementation of fiber grating sensors for in situ measurement of crustal deformation are also introduced.