WGM microprobe device for high-sensitivity ultrasound sensing

Whispering-gallery-mode (WGM) microcavities has emerged as a promising alternative to traditional probes, offering high sensitivity and wide bandwidth. In our research, we propose a novel silicon dioxide WGM microprobe device, with impressive Q factors up to 10⁷. With a sensitivity of 5.4 mPa√Hz and a bandwidth of 41 MHz at -6 dB, we have successfully conducted photoacoustic imaging on various samples using this device. What’s more, it can measure the resonance spectrum of microparticles by contact. Meanwhile, our compact and lightweight device exhibits waterproof, corrosion-resistant, and pressure-resistant properties by encapsulating in a 2 mm aluminum case which shows significant application potential in photoacoustic endoscopic detection, near-field ultrasonic detection and other aspects.