Electromagnetic wave transmission through inhomogeneous over-dense plasma

Here، the transmission of electromagnetic waves was studied through an inhomogeneous over-dense plasma medium in the presence of a magnetic field. This plasma medium is in fact a kind of left handed material (LHM)، in which the excitation of the surface waves is the principle actor for the transmission of electromagnetic waves. A specific structure was introduced for the overdense plasma and results showed that the surface waves can effectively be excited on both sides of the structure. The charge density of the plasma layer is supposed to have spatial variation، and in such a way that the density gradually (linearly) increases from both sides of the slab. In this way، the generalized electric permittivity of the plasma structure linearly acquires negative values and then، with the same rate، becomes positive. It is only considered the normal mode of the system. The amplitude of the electromagnetic waves was studied for the total structure، in the normal mode، for the perpendicular and oblique incidences. It was found that in this mode the surface waves can be excited effectively at the plasma surface، and hence the introduced structure has the capability of being used as a super lens.