Sensitivity of imaging properties of metal-dielectric layered flat lens to fabrication inaccuracies

Abstract

We characterize the sensitivity of imaging properties of a layered silver-TiO2 flat lens to fabrication inaccuracies. The lens is designed for approximately diffraction-free imaging with subwavelength resolution at distances in the order of a wavelength. Its operation may be attributed to self-collimation with a secondary role of Fabry-Perot resonant transmission, even though the first order effective medium description of the structure is inaccurate. Super-resolution is maintained for a broad range of overall thicknesses and the total thickness of the multilayer is limited by absorption. The tolerance analysis indicates that the resolution and transmission efficiency are highly sensitive to small changes of layer thicknesses.

Engineering the point spread function of layered metamaterials

“…Notably, surface roughness with RMS=5 nm of a thin silver film is sufficient to suppresses an SPP mode completely [35]. A detailed study of sub-wavelength imaging with MDM indicates that the tolerances to other parameters such as layer thickness or permittivity values are also critical [36]. Finally, in contrast to other reports, in [37] it has been found that a lens with periodic or random roughness can reduce field interference effects and provide improved focus on the transmission field.…”

Plasmonic lenses with long focal lengths

“…We consider antireflection coatings either in a form of single dielectric slab or a multilayer metaldielectric structure. This second approach is based on properties of similar metal-dielectric plasmonic lenses extensively studied in the last years [6][7][8][9][10][11][12].…”

Numerical analysis of transmission through a sub-wavelength metallic aperture or grating at visible and Terahertz wavelengths

“…A sub-wavelength slit in a perfect conductor can be used to couple a wavefront with the dimension in the order of 20 nm into a layered superlens [9][10][11][12]. …”