Ultrasonic imaging of seismic physical models using fiber Bragg grating Fabry-Perot probe

Abstract

A fiber-optic sensor has been proposed and demonstrated for the ultrasonic wave (UW) imaging of seismic physical models. The sensor probe comprises a fiber Bragg grating Fabry-Perot (FBG-FP) mounted inside the tip of an aluminum cone focusing the UW into the fiber. The FBG-FP probe possesses an excellent UW sensitivity because of the narrow-band notches on the top of the reflection spectrum caused by the Fabry-Perot (FP) interference. Because of the symmetrical structure of the sensor, it provides a directional UW detection with a high signal-to-noise ratio. As expected, the two-dimensional (2D) images of two physical models are reconstructed.