On the possibility of manipulating lightwaves via active electric charges

Abstract

In a source-free space, i.e., the classical vacuum, transverse-electro-magnetic (TEM) waves are spontaneous normal modes propagating within. Namely, a standard electromagnetic (EM) wave equation, in terms of either the electric or magnetic vector field, can be arrived at by combining Faraday’s and Ampere’s laws of Maxwell’s equations under the source-free condition. This implies that whenever there are electric charges, stationary or moving, the above EM or light waves have to be distorted in form (i.e., becoming driven modes at least), should their presence be still allowable in the now charged space. That is, electric charges may in fact be used to manipulate the formation, topology, transport and refractive manners of EM or light waves. One already well-acquainted example of such lightwave-influencing charges is passively bound charge carriers, or more precisely, the electric dipoles within optical dielectric materials in general. In this theoretical exploration, instead, attempt is aimed at electrically active charges which may be capable of affecting EM refractive properties, or maneuvering lightwaves in favorable ways to be exploited. It is noted that existing electronically-operated spatial light modulators, which mainly function through controlling liquid crystals, are irrelevant to this study.