Potential application of a homogeneous and anisotropic slab as an angle insensitive absorbing material

In this paper, a flat and incident angle independence absorbing material is proposed and numerically verified in the optical spectrum. A homogeneous and anisotropic dielectric slab as a non-reflecting layer is first reviewed, and a feasible realization strategy of the slab is then given by using layered isotropic materials. When the loss components of the constitutive materials are not zero, the slab will work as an angle insensitive absorbing layer, and the absorption rate augments with increase of the losses. As the numerical verifications, the field distributions of a metallic cylinder and a triangular metallic object individually covered by the designed absorbing layer are demonstrated. The simulation results show that the designed absorbing layer can efficiently absorb the incident waves with the property of incident angle independence at the operation frequency. This homogeneous slab can be used in one and two dimensional situations for the realization of an invisibility cloak, a carpet cloak and even a skin cloak, if it is used to conformally cover target objects.