On the Focusing of Surface Plasmonic Waves on the Free Surface of a Metal Film

Resumo

The excitation and focusing of a surface plasmonic wave on the free surface of a metal film in the Kretschmann scheme have been considered based on the theory of reflection of a plane electromagnetic wave from a flat-layered structure. A method of exciting a radially convergent surface plasmonic wave is proposed. The electric-field distribution at the focus is quantitatively investigated, and the conditions for its maximization are determined. The applications of the results obtained are discussed.