Presented in this paper is a guided wave focusing feasibility study in the thickness direction to precisely tune modes for monitoring layered materials. The in‐plane energy distributions through the thickness of multi‐layered waveguide models are numerically calculated. The experiments were also done with a pulse echo test using an angle beam transducer. The experimental results clearly show that the defect detection in a particular layer of multi‐layered specimens can indeed be established by appropriate manipulation of the phase velocity and frequency values based on the information from the wave structure profiles. © 2004 American Institute of Physics