Transparent High-Frequency Ultrasonic Transducer for Photoacoustic Microscopy Application

We report the development of an optically transparent high-frequency ultrasonic transducer using lithium niobate single-crystal and indium-tin-oxide electrodes with up to 90 % optical transmission in the visible to near infrared spectrum. The center frequency of the transducer was at 36.9 MHz with 33.9 %, at -6 dB fractional bandwidth. Photoacoustic imaging capability of the fabricated transducer was also demonstrated by successfully imaging a resolution target and mouse ear vasculatures in vivo, which were irradiated by a 532 nm pulse laser transmitted through the transducer.