High-sensitive ultrasonic sensor using fiber-tip PVC diaphragm Fabry-Perot interferometer and its imaging application

A polyvinyl chloride (PVC) diaphragm based on fiber-tip Fabry-Perot interferometer (FPI) is proposed and demonstrated experimentally for ultrasonic wave (UW) three-dimensional imaging. The sensor probe is created by coating the PVC diaphragm to the end facet of a well-cut single mode fiber (SMF) using a plastic welder. The probe performs with an ultra-high UW sensitivity due to high pressure sensitivity of the PVC, and thus is capable of detecting gradient seismic physical models with different angles. By scanning the model using the proposed sensor in water and three-dimensional signals reconstruction, the imaging of the spherical model is achieved.