The electron-induced surface plasmon excitation is investigated using the finite-difference time-domain (FDTD) method. The frequency-dependent dielectric function of metal is approximated by the Drude model and implemented by the auxiliary difference equation (ADE) method. The interaction between electromagnetic fields and electrons is simulated by the electromagnetic particle-in-cell (PIC) method. The fundamental physics of the surface plasmon excitation on a silver surface by an electron bunch is well presented. The dispersion curve of surface plasmons (SPs) in the metal is obtained through a series of simulations. Some characteristic features of the excited SPs and important length scales are observed, and the influence of SPs on the electron bunch is considered. The numerical results agree well with the analytical and experimental results in the literature.

surface plasmon excitation; FDTD analysis; Drude model; PIC method; electron bunch

University of Electronic Science and Technology of China