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Understanding the impact of order and disorder is of fundamental importance to perceive and to appreciate the functionality of modern photonic metasurfaces. Metasurfaces with disordered and amorphous inner arrangements promise to mitigate problems that arise for their counterparts with strictly periodic lattices of elementary unit cells such as, e.g., spatial dispersion, and allows the use of fabrication techniques that are suitable for large scale and cheap fabrication of metasurfaces. In this study, we analytically, numerically and experimentally investigate metasurfaces with different lattice arrangements and uncover the influence of lattice disorder on their electromagnetic properties. The considered metasurfaces are composed of metal-dielectric-metal elements that sustain both electric and magnetic resonances. Emphasis is placed on understanding the effect of the transition of the lattice symmetry from a periodic to an amorphous state and on studying oblique illumination. For this scenario, we develop a powerful analytical model that yields, for the first time, an adequate description of the scattering properties of amorphous metasurfaces, paving the way for their integration into future applications. [ABSTRACT FROM AUTHOR]

Abstract: In this paper we present a macroscopic model of a metasurface—optically dense grids of resonant scatterers located on a refracting interface. Similar models were previously built for the case when the scatterers are non-resonant electric dipoles and for the case when there is no substrate. In the present case scatterers are resonant, can have magnetic response, and for substrates with large refraction index acquire also substrate-induced bianisotropic properties. Representing the homogenized response of a metasurface to incident electric and magnetic fields through surface susceptibilities we derive the reflection and transmission formulas for semi-infinite and finite-thickness substrates. We develop a robust algorithm of the retrieval of the characteristic surface parameters from the reflection and transmission coefficients measured or exactly calculated for three different incidence angles. With numerical examples we show that the retrieved susceptibilities of metasurfaces are independent on the incidence angle and can be really called characteristic parameters. [Copyright &y& Elsevier]

In this paper we theoretically study electromagnetic reflection, transmission, and scattering properties of periodic and random arrays of particles which exhibit both electric-mode and magnetic-mode resonances. We compare the properties of regular and random grids and explain recently observed dramatic differences in resonance broadening in the electric and magnetic modes of random arrays. We show that randomness in the particle positioning influences equally on the scattering loss from both electric and magnetic dipoles, however, the observed resonance broadening can be very different depending on the absorption level in different modes as well as on the average electrical distance between the particles. The theory is illustrated by an example of a planar metasurface composed of cut-wire pairs. We show that in this particular case at the magnetic resonance the array response is almost not affected by positioning randomness due to lower frequency and higher absorption losses in that mode. The developed model allows predictions of behavior of random grids based on the knowledge of polarizabilities of single inclusions. [ABSTRACT FROM AUTHOR]