In 1952 Pines and Bohm discussed a quantized bulk plasma oscillation of electrons in a metallic solid to explain the energy losses of fast electrons passing through metal foils [1]. They called this excitation a “plasmon.” Today these excitations are often called “bulk plasmons” or “volume plasmons” to distinguish them from the topic of this book, namely surface plasmons. Although surface electromagnetic waves were first discussed by Zenneck and Sommerfeld [2, 3], Ritchie was the first person to use the term “surface plasmon” (SP) when in 1957 he extended the work of Pines and Bohm to include the interaction of the plasma oscillations with the surfaces of metal foils [4].

SPs are elementary excitations of solids that go by a variety of names in the technical literature. For simplicity in this book we shall always refer to them as SPs. However, the reader should be aware that the terms “surface plasmon polariton” (SPP) or alternately “plasmon surface polariton” (PSP) are used nearly as frequently as “surface plasmon” and have the advantage of emphasizing the connection of the electronic excitation in the solid to its associated electromagnetic field. SPs are also called “surface plasma waves” (SPWs), “surface plasma oscillations” (SPOs) and “surface electromagnetic waves” (SEWs) in the literature, and as in most other technical fields, the acronyms are used ubiquitously. Other terms related to SPs which we will discuss in the course of this book include “surface plasmon resonance” (SPR), “localized surface plasmons” (LSPs), “longrange surface plasmons” (LRSPs) and of course “short-range surface plasmons” (SRSPs).