FDTD and PSTD simulations for plasma applications

Three-dimensional finite-difference time-domain (FDTD) and pseudospectral time-domain (PSTD) algorithms, with perfectly matched layer absorbing boundary condition, are presented for nonmagnetized plasma as a special case of general inhomogeneous, dispersive, conductive media. The algorithms are tested for three typical frequency bands, and an excellent agreement between the FDTD/PSTD numerical results and analytical solutions is obtained for all cases. Several applications, such as laser-pulse propagation in plasma hollow channels, surface-wave propagation along a plasma column of finite length, and energy deposition of electron cyclotron resonance plasma source, demonstrate the capability and effectiveness of these algorithms. The PSTD algorithm is more efficient and accurate than the FDTD algorithm, and is suitable for large-scale problems, while the FDTD algorithm is more suitable for fine details. The numerical results also show that plasma has complex transient responses, especially in the low-frequency and resonance regimes. Because of their flexibility and generality, the algorithms and computer programs can be used to simulate various electromagnetic waves-plasma interactions with complex geometry and medium properties, both in time and frequency domains.