A To-Packaged Photonic MEMS Microphone with Outstanding Sensitivity Based On Self-Mixing Interferometry

We propose a photonic MEMS microphone based on self-mixing interference (SMI). The device features a compact geometry with a diameter of 6 mm and delivers an optically transduced current output that is linearly correlated with incident acoustic pressure, thereby enabling direct sound readout by laser interferometry. It achieves a -118.50-dB sensitivity (ref: 1 <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{V}/\mu \text{Pa})$</tex> and a 67.83-dB maximum signal-to-noise ratio (SNR) across speech-relevant frequencies (0–2000 Hz). Its optical transduction mechanism ensures excellent performance in weak signal detection and high-fidelity sound capture. These results underscore its promising potential for applications in acoustic detection and sound cloning.