Об электронной эмиссии из фокальной области симметрично сходящейся поверхностной плазмонной волны на свободной поверхности металлической пленки

Abstract

Based on the theory of reflection of a plane electromagnetic wave from a plane-layered structure, the excitation and focusing of a radially converging surface plasmon wave on the free surface of a gold film in the Kretschmann scheme are considered. The distribution of the electric field in the vicinity of the focus on the free surface of the film is quantitatively studied. Based on this distribution and the theory of thermofield electron emission from a metal, the time averaged current of electron emission is estimated depending on the amplitude of the normal component of the electric field of the wave at the center of the focal distribution. It was shown that the main part of the emission current comes from a region around the focus center with a diameter of the order of a tenth of the working wavelength in vacuum, and a negligible part of the emission current comes from surrounding the central maximum of the diffraction rings.