Frequency Translation of EM Waves using Time-Varying Dielectrics: Insights on Slab-Width and Duration of Permittivity Variation using FDTD

A comprehensive analysis of the effects on the electromagnetic (EM) waves propagating in the dielectric slab due to the temporal variation of the permittivity is deliberated in this paper. Frequency translation of a sine-modulated Gaussian pulse is demonstrated for different source frequencies. Using in-house one-dimensional (1D) FDTD code, a relation between source and translated frequency with permittivity contrast is established and validated using analytical solution. Finally, the independence of frequency shift from the duration of permittivity variation and the dependence on dielectric slab width to achieve the desired translated frequency is determined via detailed parametric studies.