Homogeneous-materials-constructed electromagnetic field concentrators with adjustable concentrating ratio

Abstract

Based on a two-step linear optical transformation method, a homogeneous-materials-constructed electromagnetic field concentrator whose energy concentrating ratio varies with the incident angle of the electromagnetic wave is proposed. The design is achieved by compressing the space in different directions with different ratios. Numerical simulations are performed to demonstrate the properties, especially the wave-incident angle-dependent concentrating effect of the concentrator. The relationship between the wave-incident angle and the concentrating ratio is investigated and the corresponding analytical expression is given and verified. This wave-incident angle-dependent concentrator constructed with homogeneous materials shows an advantage of facilitating the implementation in practice and provides a convenient route to continuously adjust the concentrated energy density in a pre-defined strategy.

EXPERIMENTAL REALIZATION OF STRONG DC MAGNETIC ENHANCEMENT WITH TRANSFORMATION OPTICS (Invited Paper)

“…The method we use is space compression transformation [22,23], which has been used for optical energy concentration. For simplicity, we consider a two-dimensional (2D) structure.…”

Dc Magnetic Concentrator and Omnidirectional Cascaded Cloak by Using Only One or Two Homogeneous Anisotropic Materials of Positive Permeability

“…By designing the coordinates of transformations or the geometry of the reference space, one can obtain a different distribution of special materials in the real space, which can allow for many predesigned functions (e.g., invisibility, optical illusions, subwavelength focusing, and etc.). The basic idea in this paper is the space compression transformation, which has been used for optical energy concentration [18,19]. For simplicity, we consider a two-dimensional (2D) structure in this paper.…”

“…1 of Ref. [19], where, however, energy concentration for an optical field, instead of DC magnetic field, was considered; a half-structure has also been used to cloak an object on a half-space [20]). In the reference space, all regions are free space whatever colors are used.…”

Three Dimensional Electromagnetic Concentrators With Homogeneous Material Parameters

“…Recently, Li et al [25] proposed a two dimensional homogeneousmaterials-constructed electromagnetic field concentrator whose energy concentrating ratio varies with the incident angle of the electromagnetic wave. Although the two dimensional model can help us to understand the electromagnetic properties of the homogeneous concentrator, it is just the first step towards the realization of electromagnetic concentrator.…”

“…Therefore, it is urgent to develop the three-dimensional (3D) concentrator with non-singular and homogeneous material parameters. Inspired by the work of Li et al [25] and Wang et al [26] who developed a three-step coordinate transformation method for designing invisible cloak, a 3D diamond-shaped concentrator composed of tetrahedral homogeneous blocks is presented in this paper. Permittivity and permeability of the concentrator is derived, and validated by numerical simulation.…”