Magnetic liquids under high electric fields as broadband optical diodes

Abstract

We show and give examples of how unidirectional propagation of light rays in the limit of geometric optics could arise in some magnetic fluids due to the magnetoelectric effect under weak DC magnetic fields and strong DC electric fields around half of their dielectric breakdown. For such liquids as kerosene and transformer oils, one-way propagation of light may occur for 30 nm diameter magnetic nanoparticles (e.g. cobalt) and concentrations of 2% or larger.

Controlled opacity in a class of nonlinear dielectric media

“…Driven by the recent advances in designing and tailoring new (meta)materials [1], there has been increasing interest in studying new optical phenomena in recent years. In order to remind readers of some remarkable achievements of such investigations, we mention the interesting effects of electromagnetically induced transparency (EIT) [2,3], optical systems presenting a negative index of refraction [4,5], cloaking devices [1], one-way propagation and optical isolators [6][7][8], and light-trapping devices [9,10], among many others. Regarding EIT, an experimental demonstration of the effect was reported in 1991, where an optically thick medium was shown to become transparent by means of a destructive interference caused by the application of an external electromagnetic field [11].…”