Optoacoustic imaging with an air-coupled transducer using coaxially aligned focused illumination

Optoacoustic (OA) methods have become powerful tools in biomedical research capable of retrieving functional information from biological tissues vivo. Acquisition OA signals generally relies on direct physical contact a transducer or an acoustic coupling medium with the tissue surface, which prevents applicability, e.g., open surgeries wounded tissues. Non-contact imaging has been achieved air-coupled piezoelectric transducers, provide straightforward approach for remote sensing ultrasound vibrations. However, sensitivity was hampered by suboptimal alignment between illumination and detection fields. Herein, we devised featuring central aperture light delivery coaxially aligned optical foci, thus providing optimal signal detection. Imaging phantoms mouse ear vivo is showcased raster-scanning being delivered through multimode fiber.