Propagation Of Surface Plasmon Polariton Waves Research Articles

Transmitting Surface Plasmon Polaritons across Nanometer-Sized Gaps by Optical near-Field Coupling

Metallic nanostructures can transport electromagnetic fields in the form of surface plasmon polariton (SPP) excitations, focus them into nanometric spots, and transfer them to nearby nanostructures by near-field coupling. This provides a basic functionality for designing new plasmonic devices that can greatly enhance light–matter coupling and facilitate ultrafast and efficient all-optical switching on the nanoscale. Here, we study a prototypical device geometry, a bow-tie antenna equipped with curved line gratings, for the efficient coupling of light into and across the antenna nanogap. We experimentally demonstrate the spectrally broadband launching and propagation of SPP waves over more than 10 μm on one arm of the antenna, their focusing into and transmission across the gap being studied by the plasmon outcoupling on the other arm. A substantial increase in the coupling efficiency for antennas with gap widths below 20 nm proves that the optical near-field coupling between the two antenna arms dominates the gap transmission. We find overall transmission efficiencies for nanofocusing, gap transmission, and plasmon outcoupling of up to 4%. A finite-difference time-domain simulation supports our experimental findings. This makes such bow-tie couplers an interesting platform for sensitively probing near-field coupling to single quantum emitters and for the ultrafast switching of light by light on the nanoscale.

Surface plasmon-polariton waves guided by an interface of a metal and an obliquely mounted uniaxially chiral, bianisotropic material

ABSTRACT The excitation of surface plasmon-polariton (SPP) waves was delineated for an interface of a metal and an obliquely mounted uniaxially chiral, bianisotropic material with optic axis making an arbitrary angle with the interface plane. Such a material can be fabricated as a parallel assembly of hellixes with the axis of the hellixes making an arbitrary tilt angle with the metallic substrate. The canonical boundary-value problem as well as the two prism-coupled configurations were investigated. The direction of propagation of SPP waves was restricted to be in the morphologically significant plane of the bianisotropic material that contains titled hellixes. It was found that the chirality parameter of the bianisotropic material has to have a magnitude smaller than a threshold in order for SPP waves to exist for all tilt angles. Also, the SPP wave can be excited in both prism-coupled configurations only by p-polarized plane waves.

Characteristics of Surface Plasmon Polaritons in Magnetized Plasma Film Walled by Two Graphene Layers

The theoretical analysis of surface plasmon polaritons in magnetized plasma film walled by two graphene layers is presented in this manuscript. The conductivity of graphene is calculated from the Kubo's formula. By tailoring the graphene conductivity, the propagation of Surface Plasmon Polariton wave can be controlled. Under the certain boundary conditions Maxwell's Equations in differential form are used to solve the problem. For using these wave guides we also investigate factor of confinement and comparatively length of shorter propagation for parallel plate waveguide. The effects of chemical potential (μ), plasma frequency (ωp), cyclotron frequency (ωc), relaxation time (τ), and number of layers of graphene (N) on the dispersion curve are investigated. The present work may have potential applications in nano-waveguide designing and plasma optics technology in the gigahertz frequency range.

Surface plasmon polariton waves propagation at the boundary of graphene based metamaterial and corrugated metal in THz range

Herein we study theoretically surface plasmon polariton (SPP) wave propagation along the nanostructured graphene-based metamaterial/corrugated metal interface. We apply the effective medium approximation formalism aiming to physically model nanostructured metamaterial. The transfer matrix approach is applied to compute the dispersion relationship for SPP waves. It has been concluded that the groove width (a) and the chemical potential (µ) parameters have a dramatical impact aiming to engineer resonance surface plasmon frequencies of the propagation modes. Moreover, one can tune the bandgap corresponding to non-propagation regime by modifying groove width parameter. The impact of the groove width (a) and the chemical potential (µ) on the propagation length was investigated. The present work may have potential applications in optical sensing in terahertz frequency range.

Rigorous formulation of surface plasmon-polariton wave propagation along the direction of periodicity of a one-dimensional photonic crystal: erratum

Rigorous formulation of surface plasmon-polariton wave propagation along the direction of periodicity of a one-dimensional photonic crystal: erratum

Rigorous formulation of surface plasmon-polariton wave propagation along the direction of periodicity of a one-dimensional photonic crystal

A rigorous formulation of the canonical boundary-value problem is presented to find the surface plasmon-polariton waves guided by the interface of a one-dimensional photonic crystal and metal along the direction of the periodicity. The problem is formulated using the rigorous coupled-wave approach and a dispersion equation has been obtained. The Muller's method and Newton--Raphson method were used to obtain illustrative numerical results of the dispersion equation. The solutions were found to converge as the number of Floquet harmonics increased. This formulation does not require the computation of the photonic bandgaps and directly computes the surface-wave modes. This formulation could engender new applications of plasmonics exploiting the neglected interface along the direction of periodicity of the one dimensional photonic crystals.

Design of plasmonic rectangular ribbon antenna based on graphene for terahertz band communication

This study proposes a new idea for designing antenna based on graphene for THz application in detailed analysis. Here, design of a novel graphene-based ribbon antenna is presented based on surface plasmon polariton (SPP) behavioural in graphene. Noble metals support and confine EM waves in infrared region. However, SPP wave propagation is supported by graphene in much lower frequencies of infrared region, in THz region. The conductivity of graphene and SPP waves behavioural in graphene sheet is analysed and studied for designing antenna based on new idea of ribbon antenna. The numerical simulations with COMSOL and CST are presented in proposed new idea structure of antenna. In order to achieve the desired tunable THz band communication, the parametric study method is used for the proposed graphene-based ribbon antenna to achieve higher efficiency.

Plasmonic patch antenna based on graphene with tunable terahertz band communications

This paper proposes a plasmonic graphene-based patch antenna for THz application in detailed analysis. Here, a rectangular patch antenna based on graphene presenting the Surface Plasmon Polariton (SPP) waves behavioral in graphene sheet is proposed and analyzed. In addition, the characteristics of graphene are presented and analyzed. In the Ffollowing, the SPP wave propagation in graphene is numerically and analytically studied. The numerical simulations with COMSOL and CST, Computer Simulation Technology transient solver, are presented in proposed structure. These solvers demonstrate that the efficiency of a rectangular graphene patch drastically improved by increasing the graphene layers. In order to achieve the desired low tunable terahertz band communication, parametric study method is applied on the proposed antenna.

Subfemtosecond and Nanometer Plasmon Dynamics with Photoelectron Microscopy: Theory and Efficient Simulations

We develop a theoretical model of the excitation and interference of surface plasmon polariton (SPP) waves with femtosecond laser pulses and use the model to understand the features in images from subfemtosecond time-resolved two-photon photoelectron microscopy (2PPE- PEEM). The numerically efficient model is based on the optics of SPP modes on multi-layer thin films and takes account of the excitation and interference by the incident light, its polarization, the boundary shape on the film where the plasmons are generated, the pulsed form of the excitation and the time integration associated with the PEEM method. The model explains the dominant features observed in the images including the complex patterns formed in experiments involving orbital angular momentum. The model forms the basis of an efficient numerical method for simulating time-resolved 2PPE-PEEM images of SPP wave propagation. The numerics is extremely fast, efficient and accurate, so that each image can takes as little as a few seconds to c...

Design and Optimization of a 3D Pyramidal Nanowaveguide with a Square Cross-section for Plasmonic Field Enhancement for High Harmonic Generation

Surface plasmon polariton wave propagation in a pyramidal 3D nanostructural waveguide carved in silver substrate is numerically studied by using FDTD method. Maximum field enhancement of 97 dB is obtained by using such structure which is enough to initiate high harmonic generation process. Furthermore, three times increase in amplification volume is acquired as compared with other geometries, which make the process of high harmonic generation more feasible. Moreover, effect of the polarization of the incident beam on field enhancement is also numerically investigated.

Рефлектометричні дослідження нанопористих плівок з масивом наночастинок золота

The influence of conditions occurring at the pulsed laser deposition of films with gold nanoparticles on the film porosity has been studied, by using the X-ray reflectometry. The films of two types were obtained by depositing particles (i) from the direct high-energy flow of erosion-torch particles and (ii) from the backward low-energy one. In both cases, the films were deposited either at the residual air pressure p = 10^−2 Pa or in the argon atmosphere with the pressures pAr = 5–100 Pa. In case (i), the film porosity was 0.1% at p = 10^−2 Pa and 1% at pAr ≤ 5 Pa. The plasmon properties of those films are associated with the propagation of surface plasmon-polariton waves. As the argon pressure grew further up to 100 Pa, the porosity increased to approximately 30%. In case (ii), the porosity of films deposited at pAr = 5–100 Pa onto substrates located in the target plane equaled 30 to 70% and depended on the distance from the film to the torch axis. All films with the porosity higher than 20% turned out nanocomposite structures with arrays of gold nanoparticles, which enabled us to observe the excitation of local surface plasmons.

Scalability of the Channel Capacity in Graphene-enabled Wireless Communications to the Nanoscale

Graphene is a promising material which has been proposed to build graphene plasmonic miniaturized antennas, or graphennas , which show excellent conditions for the propagation of Surface Plasmon Polariton (SPP) waves in the terahertz band. Due to their small size of just a few micrometers, graphennas allow the implementation of wireless communications among nanosystems, leading to a novel paradigm known as Graphene-enabled Wireless Communications (GWC). In this paper, an analytical framework is developed to evaluate how the channel capacity of a GWC system scales as its dimensions shrink. In particular, we study how the unique propagation of SPP waves in graphennas will impact the channel capacity. Next, we further compare these results with respect to the case when metallic antennas are used, in which these plasmonic effects do not appear. In addition, asymptotic expressions for the channel capacity are derived in the limit when the system dimensions tend to zero. In this scenario, necessary conditions to ensure the feasibility of GWC networks are found. Finally, using these conditions, new guidelines are derived to explore the scalability of various parameters, such as transmission range and transmitted power. These results may be helpful for designers of future GWC systems and networks.

Graphene-based Plasmonic Nano-Antenna for Terahertz Band Communication in Nanonetworks

Nanonetworks, i.e., networks of nano-sized devices, are the enabling technology of long-awaited applications in the biological, industrial and military fields. For the time being, the size and power constraints of nano-devices limit the applicability of classical wireless communication in nanonetworks. Alternatively, nanomaterials can be used to enable electromagnetic (EM) communication among nano-devices. In this paper, a novel graphene-based nano-antenna, which exploits the behavior of Surface Plasmon Polariton (SPP) waves in semi-finite size Graphene Nanoribbons (GNRs), is proposed, modeled and analyzed. First, the conductivity of GNRs is analytically and numerically studied by starting from the Kubo formalism to capture the impact of the electron lateral confinement in GNRs. Second, the propagation of SPP waves in GNRs is analytically and numerically investigated, and the SPP wave vector and propagation length are computed. Finally, the nano-antenna is modeled as a resonant plasmonic cavity, and its frequency response is determined. The results show that, by exploiting the high mode compression factor of SPP waves in GNRs, graphene-based plasmonic nano-antennas are able to operate at much lower frequencies than their metallic counterparts, e.g., the Terahertz Band for a one-micrometer-long ten-nanometers-wide antenna. This result has the potential to enable EM communication in nanonetworks.

Reconfigurable surface plasmon polariton wave adapter designed by transformation optics

In this paper, we propose a reconfigurable surface plasmon polariton (SPP) wave adapter designed by transformation optics, which can control the propagation of SPP waves on un-even surfaces. The proposed plasmonic device is constructed using homogeneously tunable materials (e.g. liquid crystals) so that the corresponding SPP wave transmission can be reconfigured by applying different voltages. Additionally, modified designs optimized for practical fabrication parameters are investigated. Their performance is verified by full-wave simulations. The proposed devices will pave the way towards developing tunable plasmonic devices.

Beam-scanning planar lens based on graphene

One of the most important advantages of graphene is the capability of dynamically tuning its conductivity by means of chemical doping or gate voltage. Based on this property, we propose a planar gradient index graphene-based lens transforming spherical waves of the transverse-magnetic (TM) surface plasmon polariton (SPP) wave to plane waves of the TM SPP wave with specific beam deflections. Using numerical simulations, it is confirmed that a single-atomic-layered graphene can be a platform for planar gradient-index lens, which can be applied to modulate the propagation of SPP waves.

Surface plasmon–polariton wave propagation guided by a metal slab in a sculpturednematic thin film

Surface plasmon–polariton (SPP) wave propagation guided by a metal slab in a periodicallynonhomogeneous sculptured nematic thin film (SNTF) was studied theoretically.The morphologically significant planes of the SNTF on both sides of the metalslab could either be aligned or twisted with respect to each other. The canonicalboundary-value problem was formulated, solved for SPP wave propagation, andexamined to determine the effect of slab thickness on the multiplicity and the spatialprofiles of SPP waves. Decrease in slab thickness was found to result in moreintense coupling of two metal/SNTF interfaces. But when the metal slab becomesthicker, the coupling between the two interfaces reduces and eventually SPP waveslocalize to one of the two metal/SNTF interfaces. The greater the coupling betweenthe two metal/SNTF interfaces, the smaller is the phase speed. Both the phasespeed and the attenuation of an SPP wave also depend on the twist between themorphologically significant planes of the SNTF on the two sides of the metal slab.

Multiple surface‐plasmon‐polariton waves localized to a metallic defect layer in a sculptured nematic thin film

AbstractThe propagation of a surface‐plasmon‐polariton (SPP) wave guided by a thin metallic defect layer in a sculptured nematic thin film (SNTF) – a periodically nonhomogeneous, anisotropic, dielectric material – was studied theoretically. If the defect layer is sufficiently thick, SPP waves propagate independently along the two metal/SNTF interfaces formed by the presence of the defect layer in the SNTF. As the thickness of the defect layer is reduced, SPP wave propagation is modified by the coupling of the two interfaces. The number of SPP waves increases and lower attenuation rates along the direction of propagation become possible.magnified image(© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

On the surface plasmon polariton wave at the planar interface of a metal and a chiral sculptured thin film

The solution of a dispersion equation indicates the theoretical existence of multiple modes of surface plasmon polariton wave propagation at the planar interface of a metal and a chiral sculptured thin film (STF). One mode appears to occur over a wide range of the structural period of the chiral STF, while all other modes exist only above some minimum value of the structural period, the minimum value being different for each mode. In order to excite the different modes, the interface can be incorporated in the commonplace Kretschmann configuration, for which our calculations show that the efficient excitation of different modes would require different numbers of structural periods of the chiral STF.