A photoacoustic (PA) imaging methodology utilizing coded optical excitation and correlation signal processing has been described. The basic principles of using relatively long coded waveforms and a matched filter signal compression to increase signal-to-noise ratio (SNR) and axial resolution are common in conventional radar and sonar systems. To emphasize these similarities, the proposed technique is called the photoacoustic sonar (or radar). We describe the implementation of the PA sonar using a near-IR intensity modulated continuous wave laser source and frequency-domain correlation processing of the acoustic response. Application of the PA sonar for imaging of biological materials with discrete chromophores was studied using tissue mimicking phantoms. The SNR gain achieved with linear chirps is analyzed and compared with conventional time-domain photoacoustics.

Date Published: 17 February 2011
PDF: 9 pages
Proc. SPIE 7899, Photons Plus Ultrasound: Imaging and Sensing 2011, 78990Y (17 February 2011); doi: 10.1117/12.878849

Published in SPIE Proceedings Vol. 7899:
Photons Plus Ultrasound: Imaging and Sensing 2011
Alexander A. Oraevsky; Lihong V. Wang, Editor(s)