8 research outputs found
Plus-minus construction leads to perfect invisibility
Recent theoretical advances applied to metamaterials have opened new avenues
to design a coating that hides objects from electromagnetic radiation and even
the sight. Here, we propose a new design of cloaking devices that creates
perfect invisibility in isotropic media. A combination of positive and negative
refractive indices, called plus-minus construction, is essential to achieve
perfect invisibility (i.e., no time delay and total absence of reflection).
Contrary to the common understanding that between two isotropic materials
having different refractive indices the electromagnetic reflection is
unavoidable, our method shows that surprisingly the reflection phenomena can be
completely eliminated. The invented method, different from the classical
impedance matching, may also find electromagnetic applications outside of
cloaking devices, wherever distortions are present arising from reflections.Comment: 24 pages, 10 figure
A Novel Design of Dielectric Perfect Invisibility Devices
The aim of an invisibility device is to guide light around any object put
inside, being able to hide objects from sight. In this work, we propose a novel
design of dielectric invisibility media based on negative refraction and
optical conformal mapping that seems to create perfect invisibility. This
design has some advantages and more relaxed constraints compared with already
proposed schemes. In particular, it represents an example where the time delay
in a dielectric invisibility device is zero. Furthermore, due to impedance
matching of negatively refracting materials, the reflection should be close to
zero. These findings strongly indicate that perfect invisibility with optically
isotropic materials is possible. Finally, the area of the invisible space is
also discussed