  We study the excitation of harmonic waves in thin elastic samples by a single
dislocation in arbitrary motion. We consider both screw and edge dislocations
that move perpendicularly to the surfaces of the layer. In Fourier space the
displacement velocity and dynamic stress fields generated by the motion of the
dislocations are factored as the product of two terms: one depends on the
motion of the dislocation only, while the other is independent of it, and
represents the medium's response. The latter term exhibits poles at frequencies
that satisfy the dispersion relation of the harmonic modes of the plate. In the
case of a screw dislocation the modes that are excited are a subfamily of the
antisymmetric Rayleigh-Lamb modes. For an edge dislocation a subfamily of the
symmetric Rayleigh-Lamb modes is excited, as well as the lowest lying shear
mode. The expression corresponding to a uniformly moving screw is worked out in
detail; it has singular behavior at velocities coincident with the phase
velocities of the allowed modes.
