FDTD simulation of frequency upshifting from suddenly created magnetoplasma slab

Abstract

Electromagnetic wave propagation in a suddenly created magnetoplasma slab has been studied with the use of a modified FDTD method. This method has been suitably changed so as to allow simulations of electromagnetic wave propagation problems in frequency-dependent media, such as plasma. The present formulation consists of two curl equations for electric and magnetic fields and an electron equation of motion, while ions are assumed to be motionless. The electron equation of motion includes both externally applied and self-generated magnetic fields, thus enabling examination of various phenomena that arise in suddenly created plasma. We report the influence of an external static magnetic field positioned along the direction of propagation of incident wave on frequency upshifting and power conversion of plane monochromatic and Gaussian-shaped sine waves for different ratios of characteristic frequencies of such plasmas. The concentration of charged particles has been assumed constant over the whole volume occupied by the plasma while the ionization time has been taken to be small compared to the time period of carrier frequency. The influence of a self-generated stationary magnetic field inside a suddenly created plasma and collisions have been also taken into account. The transmitted fields have been fast Fourier-transformed enabling power spectral analysis and, hence, determination of the spectral component which carries the biggest portion of the incident wave power.