Enhanced optical fiber Fabry-Perot acoustic sensor based on Mie resonant metamaterials

Advanced fiber Fabry-Perot (F-P) Acoustic sensor with anti-electromagnetic interference has been applied widely in some important monitoring fields. However, F-P acoustic sensors are limited by physical principles, and it is difficult to further improve the sensitivity and signal-to-noise ratio of the sensor. Here, a highly sensitive composite sensor, embedding a fiber F-P interferometer into a Mie resonant structure, is proposed for weak sound field detection. The customized Mie resonant metamaterials break through the sensitivity limit of F-P acoustic sensors, achieving local acoustic signal enhancement due to their high refractive index. The experimental and numerical results indicate a pressure gain of 27.60 dB and the sensor demonstrates a significant improvement in signal-to-noise ratio by 27.03 dB @1040 Hz. This technology offers a novel approach to overcoming the physical limitations of sensor detection by passively amplifying weak sound fields. The proposed sensor is suitable for applications in target azimuth identification and tracking applications.