Tilted fiber Bragg grating fixed in a polypropylene tube for ultrasonic sensing and imaging of simulated geological models

A fiber ultrasonic sensor based on tilted fiber Bragg grating (TFBG) is proposed and demonstrated both in theory and experiment. The sensor probe is packaged in a sturdily tilted polypropylene tube resulting improvements in great stability and direction dependence. In experiments, the proposed sensor performs a high ultrasonic wave (UW) sensitivity and thus it can obtain layers information in rock models. After scanning slope and surface seismic physical models, cross-section imaging of models is achieved finally by data processing and reconstruction.