A novel plate-type fiber optic sensor for enhanced underwater detection

This paper presents a novel plate-type fiber optic sensor (PT-FOS) designed for enhanced underwater detection. The sensor consists of a Mach-Zehnder interferometer (MZI), with the sensing arm featuring multiple multi-layer fiber optic coils (FOCs) adhered to a rectangular thin plate. This coils detect deformations caused by underwater acoustic waves, which are then used to reconstruct the wave information. Finite element analysis (FEA) demonstrates that the sensor achieves a sensitivity of up to 97152.93 rad/g, corresponding to a sound pressure sensitivity of -147.85 dB re rad/μPa@1Hz. Furthermore, experimental results further validate the sensor's significant response to low-frequency underwater acoustic signals, highlighting the potential of fiber optic technology in advancing underwater detection applications.