Numerical investigation of a microwave-band surface plasmon excited on an overdense plasma cylinder

The finite-difference time-domain (FDTD) method was employed to investigate the surface plasmon (SP) of the microwave band excited on an overdense plasma cylinder with various geometric scales. The extinction efficiency was calculated to determine the resonant frequency of the SP. A sequence of angular eigenmodes was observed via field distribution. The effect of plasma frequency and collision rate on the SP was also investigated. The results show that an SP on the cylinder surface can be treated as a standing wave pattern of two surface waves propagating in opposite directions. When the SP is formed around the plasma cylinder, the scatter field can be enhanced significantly. The solid plasma cylinder can be replaced by a hollow one without significant change of the SP's features, as long as its layer width well exceeds the skin depth.