Surface Wave Excitation Studied By Photography

Abstract

The scattering of visible and infrared plane waves into surface waves is studied by using photographic analysis. The surface waves are excited at either dielectric or geometric discontinuities on the surface. The standing-wave field which is generated by interference between the plane and the surface waves is recorded in a suitable layer covering the surface. When the plane wave is chosen to be incident normally on the surface it serves as a reference wave with constant phase along the surface. In this case both the amplitude and the phase of the interference pattern are entirely due to the surface wave, and thus provide a direct mapping of the surface wavetrain. As for a recording material we use photoresist for visible and PMMA for infrared radiaton, respectively. The wave images are analysed by using a phase contrast microscope in the latter or a scanning electron microscope in the former case. From the photographs the type of excited mode - bulk wave, guided wave or surface wave - can be readily identified. Furthermore the phase of scattering, the velocity of propagation and the attenuation length are directly obtained.© (1989) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.