Simulation of all fiber optic acoustic vector sensor and analysis of system sensitivity

Fiber optic sensor systems developed for acoustic vector detection are utilized in acoustic wave measurements due to their high sensitivity, small volume, low cost and insensitive to electromagnetic interference. Fiber optic based acoustic systems offer alternative methods in various fields ranging from underwater security in ports, submarine flank array sonars, underwater natural gas exploration, to fish detection. Research studies have been conducted usually on the mandrel-based interferometric systems with Fiber Bragg Grating (FBG) technology in fiber optic-based acoustic sensor designs. The applicability of FBG structure in small dimensions holds promising prospects, as it can compete with existing commercial products as well as high-sensitivity sensor designs found in the literature. This thesis presents the design of an inertial accelerometer which uses the FBG-based optical sensing method. The simulation of the system was performed based on the central wavelength shift. The simulation studies were conducted using aluminum alloy and polylactic acid (PLA) materials. As it is quite easy to process, PLA was used to produce an acoustic sensor which is capable of operating at low frequnecies. Additionally, the directional response of the inertial vector sensor made of PLA to the incident acoustic signal was investigated. The simulation studies were done for different sets of geometric parameters. The simulation results were compared to actual measured values.