Modular Analysis of Arbitrary Dipolar Scatterers

Within the paradigm of metamaterials and metasurfaces, the electromagnetic properties of composite materials can be engineered by shaping or modulating their constituents, the so-called meta-atoms. Synthesis and analysis of complex-shaped meta-atoms with general polarization properties is a challenging task. In this paper, we demonstrate that the most general dipolar response of any small object can be conceptually decomposed into a set of basic fundamental polarization phenomena, which enables immediate all-direction characterization of the electromagnetic properties of arbitrary linear materials and metamaterials. The proposed platform for modular characterization is tested on several examples of bianisotropic and nonreciprocal meta-atoms. As a demonstration of the potential of this modular analysis, we use it to design a single-layer metasurface of vanishing thickness with unitary circular dichroism. The analysis approach developed in this paper is supported by a ready-to-use computational code and can be further extended to meta-atoms engineered for other types of wave interactions, such as in acoustics and mechanics.