The open cloak

By adopting the coordinate transformation theory and the corresponding numerical approach, we investigated the method of designing open cloaks that have one or more windows to exchange information and matter with the outer environment. Compared with close cloaks, open cloaks have the quasiperfect cloaking performance and are applied to any objects especially to the moving ones that must communicate and exchange matter with the outer region, which thus opens up possibilities for practical applications of cloak technologies developed recently.