ABSTRACT
Optoacoustic image reconstruction based on the time-resolved measurement of surface displacement has employed interferometric approaches well known in the optical metrology community. This chapter provides a brief exposition of the physical principles underlying thermoelastic stress and displacement generation, and how these thermoelastic effects can be measured using interferometry. It details the use of homodyne, hetero-dyne, and confocal Fabry-Perot interferometry in optoacoustics. The chapter also provides examples of the use of these interferometric techniques for optoacoustic imaging and discusses their strengths and limitations relative to other approaches. It explains the challenges and future directions for interferometric optoacoustic imaging. Optoacoustic tomography of heterogeneous targets is possible by measuring transient displacements at multiple locations and processing the data with appropriate image reconstruction algorithms. The reduction of image acquisition time is thus an important hurdle that the optoacoustic-imaging community faces. A reduction of image acquisition time may be obtained by using multibeam interferometry combined with parallel optical detection.
