Experimental demonstration of irregular thermal carpet cloaks with natural bulk material

摘要

Invisibility carpet cloak has been typically captivated as a popular notion that can render the objects beneath invisible from detection. Previous attempts either forcefully remove the small anisotropy caused by quasi-conformal mapping or resort to stacked multilayers according to the linear transformation optics. However, these classical prescriptions face complex implications of material parameter approximations and large carpet-to-object ratio in volume. Here, we build an easy-to-implement high-performance bilayer carpet cloak based on the analytical design for three different cloaking scenarios corresponding to bell-shaped, flat and semicircular carpet cloaks. The proposed methodology, which makes no approximation in any parameters, could fit irregular shapes of objects with existing natural bulk materials. We experimentally validate the proposed design for the above three cloaking scenarios. Our approach may inspire new alternatives to the functionalities for Laplacian fields. (C) 2019 Elsevier Ltd. All rights reserved.