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 the 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.