Surface plasmon

Abstract In this chapter, the classical Drude model is used to understand the basic mechanism of plasma wave generation and sub-wavelength propagation, the concept of plasma frequency, the nature of variation of dielectric function, the dispersion relation of surface plasmons in metal-insulator and metal-insulator-metal structures, mentioning the excitation techniques. The use of metal-based plasmonics or alternative materials, like semiconductors in different ranges of EM spectra is examined. Since semiconductors and other conductors are the only materials suitable for mid-IR and THz regimes, the plasmonic properties of, and basic plasmonic devices made of semiconductors in these ranges are studied and discussed. At the end, the envisaged role of semiconductor plasmonics in information processing, uses in communication systems, and data centres will be mentioned. The chapter ends by covering a few applications like surface-enhanced Raman scattering and as biosensors.