Design, fabrication and testing of a dual-band photoacoustic transducer

Combining photoacoustic and ultrasonic imaging allows both optical and acoustic properties to be displayed simultaneously. In this paper, we describe a dual-band transducer for implementing such a multimodality imaging setup. The transducer exhibits two frequency bands so that it matches the frequency of interest in both imaging methods. An optical fiber is included in the center so that it is inherently coregistered. The transducer was fabricated from lithium niobate and comprises two concentric rings whose center frequencies are 4.9 MHz and 14.8 MHz. Pulse-echo measurements and phantom imaging were performed to demonstrate its performance characteristics.