Periodic Arrays Of Split Ring Resonators Research Articles

Efficient parallel strategy for molecular plasmonics – A numerical tool for integrating Maxwell-Schrödinger equations in three dimensions

An efficient parallelization approach to simulate optical properties of ensembles of quantum emitters in realistic electromagnetic environments is considered. It relies on balancing computing load of utilized processors and is built into three-dimensional domain decomposition methodology implemented for numerical integration of Maxwell's equations. The approach employed enables directly accessing dynamics of collective effects as the number of molecules in simulations can be drastically increased. Numerical experiments measuring speedup factors demonstrate the efficiency of the proposed methodology. As an example, we consider dynamics of nearly 700,000 diatomic molecules with ro-vibrational degrees of freedom explicitly accounted for coupled to electromagnetic radiation crafted by periodic arrays of split-ring resonators and triangular nanoholes. As an application of the approach, dissociation dynamics under strong coupling conditions is scrutinized. It is demonstrated that the dissociation rates are significantly affected near polaritonic frequencies.

Dual‐band transmission‐type circular polariser based on frequency selective surfaces

A design of dual-band transmission-type linear-to-circular polarisation converter based on frequency selective surfaces (FSSs) has been presented in this study. The proposed converter is implemented by cascading a two-dimensional periodic array of split-ring resonators bisected by metal strips and an array of rectangular patches surrounded by rectangular microstrip rings. The structure composed of metal layers and dielectric layers is designed to behave differently for field components of the two orthogonal polarisations and transmit a circularly polarised wave once illuminated by a linearly polarised plane wave within two frequency bands. Using the equivalent circuit models of the FSSs, the operating principle of the converter is presented and discussed in detail. Also, as an illustrating example, a prototype of the proposed polarisation converter operating in two frequency bands of 6.4-8.8 GHz and 12.1-13.9 GHz is simulated, fabricated and experimentally characterised. The measurement results demonstrate that the dual-band polarisation converter operates <;3 dB axial ratio in a field view of ±25° with fractional bandwidths of 31.6 and 13.8%.

On the Existence and Uniqueness of a Solution for Some Frequency-Dependent Partial Differential Equations Coming from the Modeling of Metamaterials

Several systems coming from the theory of linear wave propagation are investigated, on a bounded domain, in the presence of frequency-dependent materials like metamaterials. For each system we show generic well-posedness results under assumptions that are relevant for some models in the literature. This means existence and uniqueness of a solution for all frequencies except for a discrete locally finite and possibly empty set of frequencies. Finally, some examples of materials are studied, like a periodic array of split-ring resonators (SRR), a chiral metamaterial based on the $\Omega$-particle resonator model, a bi-anisotropic metamaterial made from SRR, absorbing boundary conditions of perfectly matched layers type for the acoustics waves, an example of acoustic metamaterial having negative bulk modulus and an elastic metamaterial.

Analysis, modeling, and applications of coaxial waveguide-based left-handed transmission lines

In this paper, a new realization of left-handed transmission lines (LHTLs) is presented. The proposed structure employs a coaxial waveguide structure to host periodic arrays of split-ring resonators (SRRs) and capacitively loaded strips (CLSs). The SRRs and CLSs are radially mounted on the inner conductor of the coaxial waveguide structure, which provides the necessary polarization for the periodic arrays of SRRs and CLSs to exhibit a negative index of refraction over a specific frequency band. The structure of the proposed coaxial waveguide-based LHTL (CW-LHTL) is optimized by studying the effect of inductive and capacitive couplings on the performance of the structure. The properties of CW-LHTL are studied by analyzing the dispersion diagram and extracting its effective permittivity and permeability. The analysis shows that the proposed CW-LHTL exhibits negative effective permittivity and permeability around the resonant frequency of the SRRs. The inductive and capacitive couplings of the SRRs and CLSs of a CW-LHTL unit cell are related to the periodicity of left-handed material (LHM) in free space. Therefore, the proposed CW-LHTL provides a reliable measurement setup to study the behavior of LHM in free space without the need to use a large number of unit cells. The coaxial waveguide measurement setup is also used to analyze different modified SRRs, which have a smaller size while operating at the same resonant frequency. A coaxial waveguide structure housing a unit cell of the proposed SRR is fabricated and tested. The measurement results show that the proposed modified SRR is up to 46% smaller in size in comparison with the traditional SRR. The applications of CW-LHTL in guided microwave systems are also discussed.