Enhanced acoustic sensitivity through high-<i>Q</i>-resonator mechanical resonance sidebands

This paper presents a method for high-resolution and high-sensitivity detection of weak acoustic signals based on the mechanical resonance calcium fluoride (<i>C</i><i>a</i><i>F</i>₂) resonator. The method utilizes sideband signals generated by the coupling of the frequency of the acoustic signals to be measured and the intrinsic mechanical frequency of the resonator. At a quality factor (<i>Q</i>-factor) of 1.25×10⁸, the signal-to-noise ratio (SNR) of the acoustic signal, as measured by the sensor in the 1-10 kHz frequency range, exhibits an improvement of over 20 dB in comparison to the non-resonant state. At 6 kHz, the system achieves an SNR of 75 dB, a sensitivity of 7.69 V/Pa, and a minimum detectable acoustic pressure (MDP) of 8.69µ<i>P</i><i>a</i>/<i>H</i><i>z</i>^1/2.