Transparent plates with optically dense surfaces such as can be obtained by thermal tempering or chemical diffusion are shown to transmit significant amounts of optical energy along their surfaces. The surface-guided waves thus obtained will carry images; some special properties of these images are described, including the chromatic variation and independence of lateral and longitudinal magnifications. The energy can be endfired from the polished end of one plate and received by another. Both direct transmission along the surface and endfire have been accomplished over distances in excess of 0.75 m.
Osterberg et al. (1964) studied this question.