Beam-to-mode conversion of a high frequency Gaussian P-wave input in an elastic plate embedded in vacuum

Using the complex source point method the mechanism was explored by which an incident well collimated beam excites the spectrum of guided modes that can be supported in a layered structure. A single elastic plate embedded in vacuum was chosen. Results for the P and SV potentials in successive cross sections were computed by the beam tracking algorithm and by normal mode expression. Results for these cross sections, where the field initially resembles a beam and after successive reflections has become blurred to the point that any resemblance to a beam has disappeared and the wave pattern becomes oscillatory, suggests the use of a hybrid ray-mode algorithm which can be structured to encompass automatically the transition from one good observable parametrization to the other.