Fiber Optic Photoacoustic-Based Steering Imaging Transducer

This letter presents a novel fiber optic imaging transducer for solving ultrasound steering problems for photoacoustic imaging (PAI). The design of the transducer is explored and verified by photoacoustic (PA) effect and Fabry-Perot (FP) principle. A directional ultrasound beam that is based on PA effect is excited by coating gold nanocomposites with polydimethylsiloxane (PDMS) at the distal end of an optical fiber with a certain degree of offset. A microlens with a concave surface is attached to the surface to focus on the length of ultrasound waves. A pulse echo signal is collected by an FP fiber optic sensor. Ultrasound field distribution is captured in order to confirm that the ultrasound beam is directional and focused as a result of the microlens. B mode imaging tests on
ex vivo
swine back rib muscle-fat slices report the transducer to own a higher depth of penetration. Ultrasound imaging is formed by combining the scanned pulse echo signal without the need for an image reconstruction algorithm. The results demonstrate a promising foundation for the prototype of the fiber optic ultrasound imaging transducer in terms of challenging environments and in
vivo
.