It has been shown recently, that varying the excitation sequence could deliver additional benefits for photoacoustic imaging, for instance, bringing additional information on the sample under study, or reducing the total acquisition time. However, for the typically used solid state laser systems, such modification requires significant increase of the systems’ complexity. We are taking an advantage of high pulse repetition rates that semiconductor laser diodes could offer. That allows the usage of dense pulse bursts with varied number of pulses and inter-pulse delays in the range of the transducer waveform duration to study the effects of the overlay of the single pulse photoacoustic responses. In this study, we conduct a pump-probe experiment, using multi-pulse excitation sequences with varied inter-pulse delays while registering the acoustic response. We show that pulse burst excitation can be beneficial for increasing the registered amplitude and suitable inter-pulse delay values can be obtained from the transducer transfer function, either known or measured. Additionally, we examine the frequency content of the multi-pulse photoacoustic response and show that it is dominated by the pulse repetition rate used. We focus on low central frequency transducers as being widely used for clinical applications.

Date Published: 13 March 2017
PDF: 6 pages
Proc. SPIE 10139, Medical Imaging 2017: Ultrasonic Imaging and Tomography, 101391J (13 March 2017); doi: 10.1117/12.2254577

Published in SPIE Proceedings Vol. 10139:
Medical Imaging 2017: Ultrasonic Imaging and Tomography
Neb Duric; Brecht Heyde, Editor(s)