The general two-dimensional open-closed cloak with tunable inherent discontinuity and directional communication

We propose general two-dimensional open-closed cloaks with controllable and inherent discontinuity, which is manipulated to create fully open, partially open, and fully closed cloaks rigorously. Multiple objects can be concealed separately in multiple controllable touching domains, with or without openings. The openings in proposed open-closed cloaks are introduced by inherent discontinuity without any approximation, and can be much larger compared to the approximate method [H. Ma, S. B. Qu, Z. Xu, and J. F. Wang, Appl. Phys. Lett. 94, 103501 (2009)]. More importantly, quasiperfect cloaking performance is kept while allowing the cloaked objects to communicate with the outer region directionally. (C) 2010 American Institute of Physics. [doi:10.1063/1.3493182]