Frequency Transformation of a Whistler Wave by A Collapsing Plasma Medium in a Cavity: FDTD Solution

A whistler wave in a cavity filled with a magnetoplasma medium is strongly affected when the plasma source is switched-off. Due to such a collapse of the plasma, the whistler wave is converted to an electric- field-intensified higher frequency wave (with an order of magnitude upshift of the frequency). In principle, it is possible to transform a 2.45 GHz source radiation to 300 GHz Terahertz radiation, with significant strength of the electric field. Finite difference time domain (FDTD) technique is used to study the effect of the following parameters: the rate of collapse, spatial plasma-density profile, collision frequency as well as the switching angle.