Full-wave analysis of conical cloaking structures

Concealing an object by only covering an open space can be realized with a conical cloak. It is shown that we can not only use a conical cloak to guide the electromagnetic (EM) wave totally around an open region without introducing any scattered field, but also design one which produces the reflection exactly the same as that caused by a dielectric half space, in addition, it is demonstrated that introducing a little loss can significantly reduce the electric field distributed at the infinite side of the conical cloak, which indicate the possibility of truncating the conical cloak in axial direction and opens a path to its physical realization. Our approach provides a practical way to achieve invisibility, especially in the case where there are two half spaces composed of different media.