Abstract

The development of photoacoustic microscopy (SPAM)^(1,2) has provided a means of studying the surface and subsurface features of solids including subsurface voids or layer disbonding which modify the efficiency of thermal diffusion into the sample. We have recently introduced a new method of thermal imaging⁽²⁾ which shares some of the features of SPAM but, rather than acoustic detection, uses the "mirage effect"⁽⁴⁾ or deflection of an optical probe beam to determine the sample surface temperature distribution.⁽⁵⁾ A theory of photothermal imaging has recently been developed for homogeneous samples⁽⁶⁾ (i.e., samples containing no thermal diffusion boundaries important to the experiment). This development includes a full treatment of 3-dimensional diffusion in the sample and the gas. The theoretical results are in good agreement with those obtained experimentally.

© 1981 Optical Society of America