Ring ultrasound transducer based miniaturized photoacoustic imaging system.

In recent years photoacoustic microscopy systems have attracted significant attention from biomedical researchers due to its ability to provide label-free imaging of hemoglobin (vasculature), lipids, and melanin with high spatial and temporal resolutions even from deeper (> 1 mm) depths inside biological tissue. This work reports the development of a low-cost and miniaturized photoacoustic (PA) imaging device for microscopy applications. A ring ultrasound transducer with 2.5 mm outer diameter and 0.5 mm inner diameter is fabricated using a 150 μm thick PZT element as the piezoelectric layer. The ring ultrasound transducer is integrated with a pulsed laser diode with integrated optical fiber which is coaxially fed through the transducer. Raster scanning of the integrated device is used to obtain 3 dimensional images of a tissue-mimicking phantom.