Ultra low-loss super-resolution with extremely anisotropic semiconductor metamaterials

Abstract

We investigate the mechanisms for the reduction of losses in doped semiconductor multilayers used for the construction of uniaxial metamaterials and show that maximizing the mean scattering time of the doped layers is key to spectrally isolating losses and maximizing anisotropy. By adjusting the layer thickness ratio of the multilayer, we show that the spectral regions of extreme anisotropy can be separated from those of high loss. Using these insights and coupled with realistic semiconductor growth parameters, we demonstrate an InAs-based superlens with an excellent loss factor α ≈ 52mm-1 and maximum perpendicular permittivity, ε⊥ > 250. By tuning the doping concentration, we show that such a system can be designed to operate anywhere in the region λ0 ≈ 5 to 25μm. We find that such a structure is capable of deep sub-wavelength imaging (< λ0/15) at superlens thicknesses up to ∼85μm (∼8λ0).

Limitations and potentials of generalized Veselago-Pendry lenses

“…Notice also that both transverse and longitudinal components of the tensors (either ε, µ) are negative for GVP lenses. The anisotropic metamaterial lenses are the subject of extensive research in this area [21][22][23][24][25][26][27][28][29][30][31][32][33][34][35]. The material properties derived there are typically optimized for ϵ z → −∞ and ϵ x → 0, which represents the limit case for the material properties derived here based on equation (15).…”

“…The material properties derived there are typically optimized for ϵ z → −∞ and ϵ x → 0, which represents the limit case for the material properties derived here based on equation (15). The proposed GVP lenses (simplified) can be realized using the metal-dielectric structures [21][22][23][24][25][26][27][28][29][30][31][32][33][34][35].…”

“…Due to the sensitivity to deviations and lens thickness, in most practical applications, subwavelength imaging is realized in the quasi-static case, where the sensitivity is relatively eased with the realistic loss and other deviation levels. In addition to VP lenses, other alternatives, such as anisotropic indefinite media, have also been extensively studied for subwavelength imaging [21][22][23][24][25][26][27][28][29][30][31][32][33][34][35].…”