Polarimetric absorptivities and Floquet-mode coherent patterns in bistatic scattering from a periodic left-handed material surface

The numerical Maxwell model is extended to electromagnetic calculations of a periodic surface of the left-handed material (LHM). Numerical simulations are illustrated for scattering, absorptivities, and absorptivity differences between ±45^∘ linear polarizations, as well as between left-handed circular (LC) and right-handed circular (RC) polarizations at 120 and 200 THz, respectively. Results indicate that the coherent wave scattering for LHM is significantly stronger than that for right-handed material (RHM), leading to markedly lower polarimetric absorptivities. In particular, it is interesting to observe the two absorptivity differences are much larger than RHM's, whereas the difference between LC and RC polarizations has never appeared from RHM's rough surface alone. Moreover, LHM absorptivities exhibit higher sensitivity to permittivity compared to RHM. The physical mechanism of such a behavior is explicated by the phenomena of local Fresnel refractions. A series of abnormal physical phenomena offer physical insights for geometric and physical parameters' information of such an azimuthal structure. Potential applications are suggested for LHM in qualitative discrimination, permittivity retrieval, and geometric information detection.