Wave Propagation in Metallic Slab Waveguides Undergoing Arbitrary Temporal Variations of Permittivity

A general and closed form solution of wave propagation in a metallic slab waveguide undergoing any arbitrary, time-varying function of permittivity is presented. The formulation is general and accurate to account for all temporal variations of permittivity. Parametric amplification and frequency conversion is demonstrated using this closed form formulation. Moreover, all results are validated and confirmed using full wave FDTD simulation. The in-house FDTD MATLAB code takes into account time variations of the permittivity.