Contemporary Physics, 1991, volume 32, number 3, pages 173-183 Optical excitation of surface plasmons: an introduction J. R. SAMBLES, G. W. BRADBERY and FUZI YANG Beginning from low level concepts the basic understanding for the optical excitation of surface plasmons is developed. Prism coupling using the attenuated total reffection technique is discussed as well as the less traditional grating coupling technique. A brief discussion of some recent developments using twisted gratings is also presented. Finally a short summary of the potential device applications is given 1.Introduction 2. Simple theory The interaction of electromagnetic radiation with an In order that we may study this interface and the interface can generate interesting surface excitations interesting electromagnetic phenomenon which oc ccurs ere are, in electromagnetic terms, a range of interfaces there we need first to examine some relatively simple of interest, for example dielectric to dielectric, dielectric concepts of solid state physics and electromagnetism. Electromagnetic radiation in isotropic media consists of ong orthogonal oscillating electric and magnetic fields rmal transverse to the direction of propagation. If, as is often h are both the case, we pass such radiation through a linear ansm polarizer then the radiation being transmitted will be plane polarized. This means there is a well specified plane ir and in which E or B oscillate, this plane containing the gnetic field vector and the propagation. Now if we consider such ident angle 0. upon a smooth anar interface then we have to consider two important d in figure 1, the incident contains orthogonal to the 0010-7514/91