Complex harmonic wave scattering as the framework for investigation of bounded beam reflection and transmission at plane interfaces and its importance in the study of vibrational modes

Deformation of bounded beams, when reflected from or transmitted through layered media, have always been discussed in connection with the generation of surface waves assuming an inhomogeneous field of leaking energy reradiating from the interface and interfering with the reflected or transmitted wave. By extending the theory of Claeys and Leroy [J. Acoust. Soc. Am. 72, 585–590 (1982)], who introduced a description of a bounded beam by means of inhomogeneous waves, it is possible to separate the scattered profile from the leaky wave component and prove that all of the features occurring in the neighborhood of critical angles can be explained as purely reflection/transmission phenomena of particular complex harmonic waves, where no propagation along the interface or reradiation is involved. The findings are illustrated for various profiles incident on different layered media both for reflection and for transmission.