Highly Sensitive Zno Doped Pet Diaphragm-Based Fiber Optic Microphone for Acoustic Pressure Sensing

In this study, a highly sensitive fiber optic microphone (FOM) based on ZnO-doped PET (PET:ZnO) diaphragm, used for the first time in the literature, is presented. The average signal-to-noise ratio (SNR) of the proposed FOM in the frequency range 1 kHz–20 kHz was determined as 51.74 dB. In the specified range, the highest SNR was measured as 73.57 dB under 14 mPa acoustic pressure for 5 kHz frequency. Corresponding to this value, the minimum detectable pressure (MDP) that can be measured with the proposed FOM at 100 Hz resolution is calculated as low as 2 µPa/Hz. With the calibration chart obtained, the sensitivity value of the proposed FOM was determined to be 151.36 mV/Pa. In addition, apart from the static pressure analysis of FOM, dynamic sound quality analysis was carried out with the PESQ algorithm. FOM achieved a high-quality score of 3.21 from this analysis, showing that it can compete with commercial microphones. Moreover, the proposed FOM is also highly advantageous because of its ease of production and low cost. The results show that the FOM has potential use in various applications, such as voice recognition, real-time communication in extreme environments, and long-distance listening in public/military/private security.