Frequency shifting of electromagnetic radiation by sudden creation of a plasma slab

The effect of switching a plasma medium of finite width (slab) on a time-harmonic plane electromagnetic wave propagating in free space is considered. The transient solution is obtained through the use of Laplace transforms. The solution is broken into two components: A component which in steady state has the same frequency as the incident wave frequency (ω0) and a B component which has an upshifted frequency ω1 =√ω20+ω2p. Here ωp is the plasma frequency of the switched plasma slab. Numerical results are presented to show the effect of the slab width on the reflected and transmitted waves. A proper choice of ω0, ωp and the slab width will yield a transmitted electromagnetic pulse of significant strength at the upshifted frequency.