Photoacoustic, photothermal, and related techniques: a review

Abstract

A review is presented of the current theoretical and conceptual understanding of physical processes involved in photoacoustic and photothermal techniques, and in related techniques employing particle beams. Emphasis is given to recent developments, and to problems needing attention. The thermoacoustic theory of the photoacoustic cell is reviewed and contrasted with the isochoric model, and the effects of mass transfer, viscosity, and porous samples are discussed. Thermal-imaging techniques are reviewed, with attention to questions of resolution, definition, and sensitivity. Progress in understanding and modeling techniques based on thermoelestic processes is considered.