The detection of ultrasound is conventionally performed by using piezoelectric transducers. Despite the ubiquity of this approach, it suffers from several drawbacks that limit its application. In particular, in the field of optoacoustic imaging, the opacity of piezoelectric materials in use puts constraints on possible illumination patterns. In addition, piezoelectric transducers generally lose sensitivity upon miniaturization, hindering the development of minimally invasive optoacoustic endoscopes. At LBIS, we develop ultrasound detectors based on interferometric principles to enable new imaging devices. Our approach relies on miniature optical resonators in silica and silicon platforms and on a unique interrogation approach called pulse interferometry.
