ON THE ACCURACY OF DEPTH-DEPENDENT THERMAL-CONDUCTIVITY RETRIEVAL IN PHOTOACOUSTIC EXPERIMENTS

We investigate the intrinsic error sensitivity of photoacoustic experi ments in obtaining reliable and accurate information on the inhomogene ous thermal conductivity below the surface. The analysis is based on t hermal wave properties and does not depend on any approximate inversio n technique. As an example, the theory is applied to the important cla ss of monotonic profiles. The theory can help us in choosing the lower frequency limit in an actual experiment. (C) 1997 American Institute of Physics.