Coupling of slow phase velocity surface waves of a planar plasma bounded by two dielectrics

Abstract EN

Coupling of electrostatic surface waves (ESW) in unmagnetized cold planar plasma has been studied analytically for various structures.

We obtained the dispersion relation governing the ESW spectra at the four interfaces involved in the general case of a plasma layer bounded by two dielectric layers of finite thicknesses with the rest of space being vacuum.

Many interesting limiting cases corresponding to the structures vacuum plasma, plasma-dielectric, vacuum-plasma-vacuum, and vacuum-plasma-dielectric have been considered and discussed.

Two surface wave modes were observed corresponding to symmetric and antisymmetric ESW modes.

In the long wavelength limit or for a thin bulk plasma, the two ESW modes were found to have distinct spectra.

For bounding layers of identical electrical properties, the two modes become degenerate and merge into a single oscillation mode for large bulk plasma thickness.

On the other hand, when the electrical properties of the bounding layers are different and for all plasma thicknesses, the modes are non-degenerate since they characterize different bounding interfaces.

Long wavelength asymptotic of the ESW modes spectra were found to shift down for a finite thickness of the bounding dielectrics.