The gain-assisted plasmonic analog of electromagnetically induced transparency (EIT) in a metallic metamaterial is investigated for the purpose to enhance sensing performance EIT-like structure. structure composed three bars one unit, two which are parallel each other (dark quadrupolar element) but perpendicular third bar (bright dipolar element), results show that, addition high sensitivity refractive-index fluctuation surrounding medium, figure merit such active metamaterials can be...

This work is published at "Optics Express 18, 18229 (2010

The flexible control of surface plasmon polaritons (SPPs) is important and intriguing due to its wide application in novel plasmonic devices. Transformation optics (TO) offers the capability either confine SPP propagation on rigid curved/uneven surfaces, or flow SPPs planar surfaces. However, TO has not permitted us confine, manipulate, waves curved Here, we propose freely using graphene. We show that can be naturally confined propagate uneven graphene surfaces with little bending radiation...

We demonstrate that the toroidal dipolar response can be realized in optical regime by designing a feasible nanostructured metamaterial, comprising asymmetric double-bar magnetic resonators assembled into toroid-like configuration. It is confirmed numerically an moment dominates over other moments. This characterized strong confinement of E-field component at toroid center, oriented perpendicular to H-vortex plane. The resonance-enhanced provide experimental avenue for various interesting...

Metalens is one kind of two-dimensional ultrathin lenses with subwavelength artificial structures that can focus light in a compact, flexible way. However, most strategies for designing metalenses only work on specific spin state (i.e., either right- or left-circularly polarized light), hindering simultaneous control both spins. Utilizing the Pancharatnam-Berry phase and propagation phase, we rationally each light. As proof-of-concept demonstrations, here numerically experimentally realize...

The toroidal response is numerically investigated in a multifold double-ring metamaterials at the antibonding magnetic-dipole mode (i.e., antiparallel magnetic dipoles one fold). This intriguing resonance considered as result of magnetoelectric effect due to broken balance electric near-field environment. We demonstrate that dipole can improve quality factor spectrum. In viewing design flexibility on geometry, such will offer advantages application potentials dipolar moment.

Abstract Multichannel metasurfaces become one of the most significant development trends, as they exhibit versatile manipulation abilities on electromagnetic fields and provide a promising approach to constitute compact devices with various complex functions, especially in optical encryption due its capabilities multichannel, high complexity, concealment. However, existent multichannel based technology can only realize two channels near-field, or perform three near- far-field. In this paper,...

Abstract Image steganography based on intelligent devices is one of the effective routes for safely and quickly transferring secret information. However, optical image has attracted far less attention than digital due to state‐of‐the‐art technology limitations high‐resolution imaging in integrated devices. Optical metasurfaces, composed ultrathin subwavelength meta‐atoms, are extensively considered flat optical‐imaging nano‐components with high‐resolutions as competitive candidates...

Dynamic dipolar toroidal response is demonstrated by an optical plasmonic metamaterial composed of double disks. This with a hotspot localized E-field concentration well-behaved cavity mode that exhibits large Purcell factor due to its deep-subwavelength volume. All-optical Hall effect (photovoltaic) this moment numerically, in mimicking the magnetoelectric multiferroic systems. The result shows promising avenue explore various phenomena associated intriguing dynamic moment.

The propagation of surface plasmon polariton (SPP) wave can be controlled by tunable graphene conductivity via electrostatic gating and/or chemical doping. Here, we propose an alternative way to manipulate the SPP waves efficiently designing thickness dielectric cladding on graphene. Meanwhile, properties changed gradually rather than abruptly through topology cladding. Compared traditional method, proposed approach is more convenient for machining with lower scattering loss. A plasmonic...

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

The optical propagation properties and magnetic polariton behaviors in perforated metal/dielectric layered structures are numerically investigated at near-IR region. A developed three-metal-layer (TML) structure is specially inspected as a simple case. Strong coupling effect of discovered this system, which explains why TML reveals better negative-refraction property than the reported double-metal-layer (DML) structure. clear LC-circuit model presented to describe physical mechanism...

An otherwise dark magnetic dipole resonance in a split-ring resonator can be excited electrically with Fano-type profile once the symmetric environment for this is broken respect to polarized electric-field direction of incident waves. When asymmetrically induced narrow coincides broad dipolar at an identical frequency regime, metamaterial analogue electromagnetically-induced transparency (EIT) window formed. We demonstrate that environmental-asymmetry condition introduced dielectrically as...

We propose a novel approach to generating optical pulling forces on gold nanowire, which are placed inside or above hyperbolic metamaterial and subjected plane wave illumination. Two mechanisms found induce the force, including concave isofrequency contour of excitation directional surface plasmon polaritons. systematically study under various conditions, wavelength, angle incidence light, nanowire radius. It is shown that force enabled by metamaterials broadband insensitive incidence. The...

The study of band topology in photonic crystals was primarily focused on near-field effects, including edge states and high-order corner states. However, this work investigated the polarization distribution radiated fields for crystal slabs to get their far-field properties topology. We introduced a topological invariant—the winding number around Brillouin zone boundary confirmed robust correspondence between it Chern energy bands from perspective symmetry, which can be used analyze process...

A wedge-shaped structure made of split-ring resonators (SRR) and wires is numerically simulated to evaluate its refraction behavior. Four frequency bands, namely, the stop band, left-handed ultralow-index positive-index are distinguished according refracted field distributions. Negative phase velocity inside wedge demonstrated in band Snell's Law conformed terms behaviors different bands. Our results confirmed that negative index indeed exists such a composite metamaterial also provided...

This paper investigates the radiation properties of two coupled split-ring resonators (SRRs). Due to electromagnetic coupling, hybrid magnetic plasmon modes were induced in structure. Our calculations show that loss structure was greatly suppressed by hybridization effect. led a remarkable increase $Q$ factor system compared single SRR. By adjusting distance between SRRs, changed correspondingly due different coupling strengths. resulted functioned as type nanocavity with an adjustable factor.

A bulk left-handed metamaterial with fishnet structure is investigated to show the optical loss compensation via surface plasmon amplification assistance of gain medium PbS quantum dots. Simultaneously negative permittivity and permeability are confirmed at telecommunication wavelength (1.5 μm) by retrieval effective electromagnetic property. The dependence enhanced transmission on coefficient, as well propagation layers, demonstrates that ultralow feasible in metamaterials.

Plasmon toroidal mode is a unique electromagnetic resonance that cannot be expanded by general electronic or magnetic multipoles. Usually, this excitation needs complicated nanostructures, which challenge for sample fabrications, especially nanodesigns with optical resonant frequencies. In work, we designed circular V-groove array and studied its toroidal-mode angle-resolved reflection experimentally numerically. Our results show plasmon around wavelength 700 nm can excited in simple...

Analogues of electromagnetically induced transparency (EIT) in metamaterials were usually based on complex structures, either by different resonators or an introduction symmetry-broken geometry. In this work, we propose a symmetric U-shaped structure to demonstrate EIT-like transmission peak that is tunable with the rotation angle resonators. It demonstrated doubly degenerate modes quality factors, sharing same resonator, responsible for spectrum due destructive interference between them.

Due to metal losses in plasmonic metamaterials, high-refractive-index dielectrics are promising improve optical performances of their metallic counterparts. In this paper, a LiTaO(3) microtube metamaterial is numerically investigated explore the toroidal dipolar resonance based on multipole expansion theory. The local field strength probed central axis greatly enhanced for mode, forming strong hot spot concentrated deep-subwavelength scale. Furthermore, we also show influences geometrical...

Abstract We mimic unique honeycomb structure as well its functions of storing honey and pollen to assemble Au nanoparticle pattern on honeycomb-like Al nanobowl array by utilizing solid state dewetting process. Patterned nanoarrays ‘one particle per bowl’ with tunable plasmonic bands ranging from the visible near-infrared region are fabricated finely selecting initial thickness film, geometry thermal treatment parameters. This work presents a powerful approach nanoparticles into high density...

Using various monosaccharides as reductant, we synthesized Ag nanoparticles (NPs) in seconds employing the household microwave method described earlier. The NPs containing colloidal solution showed distinctive colors with varying <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mrow><mml:msub><mml:mrow><mml:mi>λ</mml:mi></mml:mrow><mml:mrow><mml:mtext>max</mml:mtext></mml:mrow></mml:msub></mml:mrow></mml:math>. sizes of formed varied significantly from 10 to 35 nm good...

Defects lower the performance of perovskite solar cells by playing as recombination centers carriers and migration channels ions under illumination. Here we used various kinds lights to assist synthesis in sequential vapor deposition perovskite. Without applying light, iodine accumulated on film surface, plenty defects existed as-fabricated device. White light forced more into bulk, removing excess surface leading improved homogenization, consequently, most were annihilated. Devices with...

The high sensitivity detection of chirality is great importance in fields physics, biology, and life sciences. Emerging strategies attempt to generate the superchiral with metasurfaces maximize chiral light-matter interaction. Although these studies have mostly considered transverse superchirality, longitudinal optical also plays a very important role interactions. In this paper, conditions for generating optimal superchirality are demonstrated vector diffraction theory. Accordingly,...