DEPTH-DEPENDENT TWO-DIMENSIONAL THERMAL-WAVE SOURCE PROFILING IN HOMOGENEOUS MEDIA.

The main thrust of thermal-wave infrared (IR) microscopy has largely been concerned with the characterization of the amplitude and phase of the received IR radiation emitted from the surface of a solid in which thermal waves are propagating. An experiment designed to test the physical validity of a thermal-wave inversion technique is described. This technique allows one to spatially characterize a thermal-wave source in a homogeneous, isotropic medium, given certain boundary conditions and a priori statistical assumptions. Results for the thermal-wave profiling in an ultrasonically excited thin sheet of mylar are compared with those obtained using an equivalent mathematical model.