Design of high-transmission metallic meander stacks with different grating periodicities for subwavelength-imaging applications

Abstract

When replacing a bulk negative index material (NIM) with two resonant surfaces that allow for surface plasmon polariton (SPP) propagation it is possible to recreate the same near-field imaging effects as with Pendry's perfect lens. We show that a metallic meander structure is perfectly suited as such a resonant surface due to the tunability of the short (SRSPP) and long range surface plasmon (LRSPP) frequencies by means of geometrical variation. Furthermore, the Fano-type pass band between the SRSPP and LRSPP frequencies of a single meander sheet retains its dominant role when being stacked. Hence, the pass band frequency position, which is determined by the meander geometry, controls also the pass band of a meander stack. When building up stacks with different periodicities the pass band shifts in frequency for each sheet in a different way. We rigorously calculate the spectra of various meander designs and show that this shift can be compensated by changing the remaining geometrical parameters of each single sheet. We also present a basic idea how high- transmission stacks with different periodicities can be created to enable energy transfer at low loss over practically arbitrary distances inside such a stack. The possibility to stack meander sheets of varying periodicity might be the key to far field superlenses since a controlled transformation of evanescent modes to traveling wave modes of higher diffraction order could be enabled.

Fano resonance in novel plasmonic nanostructures

“…Coupled waveguide grating structure is another compelling approach to generate FRs . Knowing that the grating structure exhibits waveguide resonance, Christ et al.…”

“…Coupled waveguide grating structure is another compelling approach to generate FRs [174][175][176][177][178][179][180]. Knowing that the grating structure exhibits waveguide resonance, Christ et al [181] investigated the coupling between localized particle plasmons and optical waveguide modes, which leads to the appearance of a Fano signature in transmission spectra.…”

“…One important factor in the above‐mentioned studies is the scaling of nanostructures exhibiting FR . Most of the experimentally realized plasmonic structures have a characteristic scale of 100 nm and beyond . It has a deep physical reason based on the Mie theory, which has been discussed in less detail.…”

Polarization scramblers with plasmonic meander-type metamaterials

“…It was found that with certain meander geometries, plasmon resonances induce a hightransmission pass band, which is bounded by two Fano-type resonances ( Fig. 2(a)) [21,29]. This high-transmission pass band is the main reason for using meander structures for the proposed depolarizer.…”

Near field of stacked diffraction gratings

“…In the near field, systems with 1 and 2 gratings have been well analyzed since they produce Talbot and Moiré effects, respectively [6,2]. Nevertheless, there exist optical devices which use three and even more diffraction gratings in stack as, for example, optical encoders [7][8][9][10], or other applications [11][12][13]. Besides, optical devices in which the beam passes through the same grating several times can also be found [14].…”