Chenghao Lao

Abstract Ultrasonic sensors are widely used for object detection and localization in underwater and biological settings. The operational range and spatial resolution are inherently limited by sensor sensitivity, in which conventional piezoelectric transducers have been overwhelmed by advanced photonic sensors. Here, we demonstrate an optomechanical ultrasonic sensor integrated into a photonic platform, which comprises a suspended SiO2 membrane embedded with a high-Q Si3N4 microring resonator.

Popular Summary When light shines on a solid, it causes the solid to vibrate, generating sound waves. This optomechanical process is known as Brillouin scattering, and it has numerous applications in microscopy, sensing, and lasing. However, Brillouin scattering in bulk materials is often quite weak and requires devices like optical microresonators to enhance it.