Metal–dielectric hybrid nanoantennas for efficient frequency conversion at the anapole mode

• Valerio F. Gili,
• Lavinia Ghirardini,
• Davide Rocco,
• Giuseppe Marino,
• Ivan Favero,
• Iännis Roland,
• Giovanni Pellegrini,
• Lamberto Duò,
• Marco Finazzi,
• Luca Carletti,
• Andrea Locatelli,
• Aristide Lemaître,
• Dragomir Neshev,
• Costantino De Angelis,
• Giuseppe Leo and
• Michele Celebrano

Beilstein J. Nanotechnol. 2018, 9, 2306–2314, doi:10.3762/bjnano.9.215

• -field enhancement, which are characteristic of this mode. Plasmonic nanostructures, on the other hand, remain the most promising solution to achieve strong local field confinement, especially in the NIR, where metals such as gold display relatively low losses. Results: We present a nonlinear hybrid

• circulates in the plane of the disk and is confined inside it. We also evaluated the electric field enhancement inside the cylinder, defined as the ratio between the total field E and the incident field E0, as a figure of merit to assess the performance of the ring-assisted antenna. The maximum field

• , therefore, the field enhancement inside the structure remains rather limited. In this work, by exploiting the plasmonic ring, we obtain a 20-fold increase in the field intensity enhancement averaged over the whole structure volume, F, as compared to the bare nanopillar (see Figure 3d), which is comparable

The role of adatoms in chloride-activated colloidal silver nanoparticles for surface-enhanced Raman scattering enhancement

• Nicolae Leopold,
• Andrei Stefancu,
• Krisztian Herman,
• István Sz. Tódor,
• Stefania D. Iancu,
• Vlad Moisoiu and
• Loredana F. Leopold

Beilstein J. Nanotechnol. 2018, 9, 2236–2247, doi:10.3762/bjnano.9.208

• nanoparticles (also called surface plasmon resonances) [8]. Although this model does not require a chemical contact, the magnitude of the electromagnetic field outside the particle decreases with the third power of radial distance [9]. This means that the field enhancement of Raman scattering decreases strongly

Dumbbell gold nanoparticle dimer antennas with advanced optical properties

• Janning F. Herrmann and
• Christiane Höppener

Beilstein J. Nanotechnol. 2018, 9, 2188–2197, doi:10.3762/bjnano.9.205

• electromagnetic field enhancement and confinement. This ratio, taken as a measure of the performance of an antenna, can even exceed that exhibited by trimer AuNP antennas composed of comparable building blocks with larger gap sizes. Fluctuations in the far-field and near-field properties are observed, which are

• likely caused by distinct deviations of the gap geometry arising from the faceted structure of the applied colloidal AuNPs. Keywords: atomistic plasmonics; dumbbell dimer antennas; electromagnetic field enhancement; light confinement; nanolens; nanoscale morphology; Introduction The introduction of the

• non-linear responses generated in these structures [39]. In addition, the asymmetry induces a cascade of the electromagnetic field enhancement towards the pointed end of the structure such that these structures are often discussed in terms of acting as a nanolens [10][40][41][42][43]. Although the

Toward the use of CVD-grown MoS₂ nanosheets as field-emission source

• Geetanjali Deokar,
• Nitul S. Rajput,
• Junjie Li,
• Francis Leonard Deepak,
• Wei Ou-Yang,
• Nicolas Reckinger,
• Carla Bittencourt,
• Jean-Francois Colomer and
• Mustapha Jouiad

Beilstein J. Nanotechnol. 2018, 9, 1686–1694, doi:10.3762/bjnano.9.160

• factor) is a particular value of the principal Schottky–Nordheim barrier function U. β is the local electrical field enhancement factor. is the work function of the emitter (considered to be 4.04 eV here [29]). In Figure 6a, the current density versus electric field (J–E) curve of the transferred MoS2

• from the local electric field. The ratio of the actual local electric field to the applied average electric field is known as the field-enhancement factor. In the present case, the field-enhancement factor, commonly used for evaluating FE properties, is calculated from the slope m of the F–N plot (a

• density as a function of the electric field for the transferred MoS2 NSs on FTO/glass. The inset shows the corresponding FN plot with a linear fitting used for estimating the field-enhancement factor. (b) The long-term field-emission stability for the same sample at the pressure of ca. 10−6 mbar with

Mechanistic insights into plasmonic photocatalysts in utilizing visible light

• Kah Hon Leong,
• Azrina Abd Aziz,
• Lan Ching Sim,
• Pichiah Saravanan,
• Min Jang and
• Detlef Bahnemann

Beilstein J. Nanotechnol. 2018, 9, 628–648, doi:10.3762/bjnano.9.59

• the LSPR feature in the Cu7S4@Pd catalyst. They found that Pd NPs showed weak LSPR absorption at 808, 980 and 1500 nm, while Cu7S4 exhibited obvious electrical field enhancement at these wavelengths; thus Cu7S4 was found to be the dominant contributor to the LSPR feature [111]. Using a similar

Ta₂N₃ nanocrystals grown in Al₂O₃ thin layers

• Krešimir Salamon,
• Maja Buljan,
• Iva Šarić,
• Mladen Petravić and
• Sigrid Bernstorff

Beilstein J. Nanotechnol. 2017, 8, 2162–2170, doi:10.3762/bjnano.8.215

• light to nano-scale structures via local surface plasmon resonance (LSPR) [1]. LSPR produces a strong near-field enhancement and a local heating [2][3], which are considered to be promising in several applications ranging from surface-enhanced Raman scattering [4], to catalysis [5] and heat-assisted

Optical response of heterogeneous polymer layers containing silver nanostructures

• Miriam Carlberg,
• Florent Pourcin,
• Olivier Margeat,
• Judikaël Le Rouzo,
• Gérard Berginc,
• Rose-Marie Sauvage,
• Jörg Ackermann and
• Ludovic Escoubas

Beilstein J. Nanotechnol. 2017, 8, 1065–1072, doi:10.3762/bjnano.8.108

• information about the reflection, transmission, absorption of the material as well as the complex optical indices, n and k. Finite difference time domain simulations of nanoparticles in thin film layers allow the visualization of the nanoparticle interactions or the electric field enhancement on and around

• electric field enhancement. The incoming light is either absorbed or scattered by the NPs [8]. The absorption and scattering are commonly referred to as optical extinction. Single NPs are widely studied under different characterization techniques and computer modeling, such as Mie theory for spherical NPs

• NPs, the thin film layers will absorb in the visible wavelength range. This leads to applications of plasmonic thin film layers for photodetectors [10], photovoltaics [6][11] or nonreflective coatings [12][13][14]. In this works, silver NPs were chosen for their high electric field enhancement in the

Near-field surface plasmon field enhancement induced by rippled surfaces

• Mario D’Acunto,
• Francesco Fuso,
• Ruggero Micheletto,
• Makoto Naruse,
• Francesco Tantussi and
• Maria Allegrini

Beilstein J. Nanotechnol. 2017, 8, 956–967, doi:10.3762/bjnano.8.97

• of local surface patterns in the tuning of these resonances as a function of wavelength and electric field polarization. The effect of nanoscale roughness on the surface plasmon polaritons of randomly patterned gold films is numerically investigated. The field enhancement and relation to specific

• of fundamental relevance to study near-field nonlinear optical phenomena [1][2]. Particularly relevant is the strong electric field enhancement on resonance that can be of special interest for various applications, such as surface-enhanced Raman spectroscopy (SERS) [3][4], tip-enhanced Raman

• properties [13][14]. Although the occurrence of surface plasmon-enhanced nonlinear optical effects is rather well understood, further investigation into the spectral dependence and magnitude dependence of the field enhancement as related to surface morphology [2]. Particular attention has been paid to the

Influence of hydrofluoric acid treatment on electroless deposition of Au clusters

• Rachela G. Milazzo,
• Antonio M. Mio,
• Giuseppe D’Arrigo,
• Emanuele Smecca,
• Alessandra Alberti,
• Gabriele Fisichella,
• Filippo Giannazzo,
• Corrado Spinella and
• Emanuele Rimini

Beilstein J. Nanotechnol. 2017, 8, 183–189, doi:10.3762/bjnano.8.19

• surface. The process stops after a certain thickness of oxide is formed and on top of it gold atoms agglomerate as solid clusters [18][19][20][21]. The optical properties of these gold clusters depend on their shape and morphology. It is reported in literature that the local field enhancement factor of

Effect of Anderson localization on light emission from gold nanoparticle aggregates

• Mohamed H. Abdellatif,
• Marco Salerno,
• Gaser N. Abdelrasoul,
• Ioannis Liakos,
• Alice Scarpellini,
• Sergio Marras and
• Alberto Diaspro

Beilstein J. Nanotechnol. 2016, 7, 2013–2022, doi:10.3762/bjnano.7.192

• -similar pattern allowed nanofocusing and high field enhancement to be achieved in the subwavelength regime. The principle of confinement of optical pulses in metal nanoparticles arises from the existence of plasmons in metals, consisting of collective oscillations of an electron gas. In this work, we

• symmetric plasmon has a larger dipole moment and couples easily with light giving rise to plasmon absorption [20]. This can be seen in the PL emission from the AuNPs, since field enhancement due to confinement is possible by controlling the gaps and distances between the nanoparticles to create hot spots

• field enhancement. However, the scattered values indicate that the plasmonic response does not originate from a uniform distribution of the aggregated mass. In other words, the size distribution and the distances between the aggregated objects, following Equation 6, vary widely around those of the

The role of morphology and coupling of gold nanoparticles in optical breakdown during picosecond pulse exposures

• Yevgeniy R. Davletshin and
• J. Carl Kumaradas

Beilstein J. Nanotechnol. 2016, 7, 869–880, doi:10.3762/bjnano.7.79

• -field enhancement than on the mass or absorption cross-section of the nanostructure. These findings can be used to advance the nanoparticle-based nanoscale manipulation of matter. Keywords: electron plasma; finite element method; optical breakdown; plasmon coupling; plasmonic nanoparticles

• resonance peaks of gold nanospheres towards the near infrared region. (This is useful in biological applications, where light has a good penetration depth) [5][16]. The use of plasmonic nanoparticles and the associated near-field enhancement has been used in applications based on the laser-induced breakdown

• a high near-field enhancement surrounding the gold nanorod (the near-field regime). At picosecond pulses with low irradiation fluence, nanoparticle-mediated LIB is dominated by photo-thermal emission due to the fast temperature increase of the electrons in the nanostructure. The lack of a detailed

Templated green synthesis of plasmonic silver nanoparticles in onion epidermal cells suitable for surface-enhanced Raman and hyper-Raman scattering

• Marta Espina Palanco,
• Klaus Bo Mogensen,
• Marina Gühlke,
• Zsuzsanna Heiner,
• Janina Kneipp and
• Katrin Kneipp

Beilstein J. Nanotechnol. 2016, 7, 834–840, doi:10.3762/bjnano.7.75

• confined local optical fields in the vicinity of metal nanostructures. Plasmonic field enhancement enables optical and spectroscopic measurements at unprecedented sensitivity and spatial resolution [2]. For chemical analysis, Raman spectroscopy performed in enhanced local fields allows for the detection

Linear and nonlinear optical properties of hybrid metallic–dielectric plasmonic nanoantennas

• Mario Hentschel,
• Bernd Metzger,
• Bastian Knabe,
• Karsten Buse and
• Harald Giessen

Beilstein J. Nanotechnol. 2016, 7, 111–120, doi:10.3762/bjnano.7.13

• ]. One can also transport energy on deep subwavelength length scales [5], create the plasmonic analogue of electromagnetically induced transparency (EIT) [6][7][8][9], and construct systems with tailorable near-field enhancement and confinement [10][11][12][13]. What is more, the resonant behavior of

• combination of field enhancement and nonlinear optics has already been proposed in the first publications on metamaterials and plasmonics [57], only a very limited number of papers report conclusive experiments that are well supported by data [58][59][60][61][62][63][64][65][66][67][68]. In most experiments

Improved optical limiting performance of laser-ablation-generated metal nanoparticles due to silica-microsphere-induced local field enhancement

• Zheren Du,
• Lianwei Chen,
• Tsung-Sheng Kao,
• Mengxue Wu and
• Minghui Hong

Beilstein J. Nanotechnol. 2015, 6, 1199–1204, doi:10.3762/bjnano.6.122

• the nanoparticle dispersion. Keywords: laser ablation; local field enhancement; microspheres; nanoparticles; optical limiting; Introduction Laser ablation in liquid (LAL) is a versatile technique to fabricate nanoparticles. Conventional synthesis of nanoparticles by chemical reactions is usually

• effect induced by the light focusing of the silica microspheres. We have also simulated the light energy enhancement for different sizes of microspheres, as shown in Table 1. It is found that larger sized microspheres induce a stronger local field enhancement. In our experiment, we found that large sized

• (>1 μm) microspheres were not stable in the nanoparticle dispersion. The microspheres settle to the bottom of the cuvette after tens of seconds after introducing them in the dispersion. Since the local field enhancement can be increased by larger sized microspheres, high viscosity liquids need to be

Superluminescence from an optically pumped molecular tunneling junction by injection of plasmon induced hot electrons

• Kai Braun,
• Xiao Wang,
• Andreas M. Kern,
• Hilmar Adler,
• Heiko Peisert,
• Thomas Chassé,
• Dai Zhang and
• Alfred J. Meixner

Beilstein J. Nanotechnol. 2015, 6, 1100–1106, doi:10.3762/bjnano.6.111

• intensity, the effective Raman scattering coefficient in the tunneling junction taking the near field enhancement into account is estimated as σR ≈ 10−9. Having found the steady-state solution to Equation 1 and Equation 3, the total radiative yield γem of the hybrid system at different bias voltages and

Electromagnetic enhancement of ordered silver nanorod arrays evaluated by discrete dipole approximation

• Guoke Wei,
• Jinliang Wang and
• Yu Chen

Beilstein J. Nanotechnol. 2015, 6, 686–696, doi:10.3762/bjnano.6.69

• by the exponential dependence of EF on the lateral gap size. Our results also suggested that absorption rather than extinction or scattering could be a good indicator of EM enhancement. It is expected that the understanding of the dependence of local field enhancement on the structure of the

• understanding of the dependence of local field enhancement on the structure of the nanoarrays and incident excitations will shine light on the optimal design of efficient SERS substrates and facilitate their applications in biomedical sensing and chemical analysis. Numerical calculations DDA method DDA is a

• . showed that this generalized DDA method was an efficient and versatile numerical approach for calculations of optical properties of AgNR array [23]. To investigate the SERS enhancement of AgNR arrays fabricated by OAD method in terms of EM mechanism, we simulated the local field enhancement of the

Hollow plasmonic antennas for broadband SERS spectroscopy

• Gabriele C. Messina,
• Mario Malerba,
• Pierfrancesco Zilio,
• Ermanno Miele,
• Michele Dipalo,
• Lorenzo Ferrara and
• Francesco De Angelis

Beilstein J. Nanotechnol. 2015, 6, 492–498, doi:10.3762/bjnano.6.50

• field enhancement; plasmonics; Raman spectroscopy; SERS; Introduction Cells are extremely complex systems that consist of hundreds of different molecules that can react and give rise to many different chemical processes. In addition to the complexity of the cellular chemical environment, it must also

• ][18] and magnetic field enhancement [19]. In these various disciplines, the rise of a trend targeting high performance spectroscopy techniques for biomolecules and cells can be recognized. Raman spectroscopy has already been implemented for whole live cell imaging [20] as well as its biological

• without disrupting the plasmon activity, thus opening their exploitation in the majority of the above cited fields. Results and Discussion Optimization of the electric field enhancement The possibility of obtaining three-dimensional hollow nanoantennas with a high aspect ratio through an innovative

Green preparation and spectroscopic characterization of plasmonic silver nanoparticles using fruits as reducing agents

• Jes Ærøe Hyllested,
• Marta Espina Palanco,
• Nicolai Hagen,
• Klaus Bo Mogensen and
• Katrin Kneipp

Beilstein J. Nanotechnol. 2015, 6, 293–299, doi:10.3762/bjnano.6.27

• Raman signal of the molecule. Using excitation in the NIR, the green silver nanoparticles provide only modest enhancement factors between 10 and 100 in agreement with computations of field enhancement factors for individual small silver spheres in the near infrared (NIR) [24]. The poor aggregation

Exploring plasmonic coupling in hole-cap arrays

• Thomas M. Schmidt,
• Maj Frederiksen,
• Vladimir Bochenkov and
• Duncan S. Sutherland

Beilstein J. Nanotechnol. 2015, 6, 1–10, doi:10.3762/bjnano.6.1

• results from the large structural asymmetry between the cap and the BW-SPP. The field distributions, particularly for the two anti-symmetric modes (peak at 803 nm and dip at 1045 nm) show a strong field confinement between the cap and the hole with field enhancement up to 25 and 29. Figure 8 shows the

Localized surface plasmon resonances in nanostructures to enhance nonlinear vibrational spectroscopies: towards an astonishing molecular sensitivity

• Dan Lis and
• Francesca Cecchet

Beilstein J. Nanotechnol. 2014, 5, 2275–2292, doi:10.3762/bjnano.5.237

• of biological properties and behaviours, and has opened the way to fascinating biomedical and biotechnological applications of single molecules and nanomaterials [7][17][18][19][20]. This success is mostly due to the electromagnetic near-field enhancement achieved thanks to more and more

• IR or spontaneous Raman spectroscopies. To push forward the performance of both techniques, the coupling of the molecular coherence and power-law intensity dependence with the near-field enhancement from surface plasmon resonance has been initiated, and some demonstrations of an extreme sensitivity

• surface of the nanoparticle [54][55][56][57][58]. Besides, the near-field enhancement has led to a very large variety of advances in many fundamental and applied areas of science. Large boosts in the sensitivity and intensity have been reported for a very wide variety of nanoparticle shapes, dimensions

Properties of plasmonic arrays produced by pulsed-laser nanostructuring of thin Au films

• Katarzyna Grochowska,
• Katarzyna Siuzdak,
• Peter A. Atanasov,
• Carla Bittencourt,
• Anna Dikovska,
• Nikolay N. Nedyalkov and
• Gerard Śliwiński

Beilstein J. Nanotechnol. 2014, 5, 2102–2112, doi:10.3762/bjnano.5.219

• microscope and inspection spectroscopic measurements. The effect of the nanostructure morphology on plasmonic properties (such as resonance position and damping), the near- and mid-field enhancement of the optical signal, and evidence of sensing capability are discussed. Moreover, the possibility of tuning

• -field intensities |E|2 refer to the plane parallel to substrate surface and distanced by R from it. Magnitude of the electromagnetic field enhancement is related to the electric field strength of the incident light (E = 1 V/m) which is illuminating the surface orthogonally. Distributions obtained under

• depending on the excitation energy where the distribution in particle size, shape and also inter-particle distance are the main contributions to the observed effect. Values of the field enhancement due to SPR lie within one order of magnitude for the sparsely-packed Au nanostructures in Figure 1a and

Observation and analysis of structural changes in fused silica by continuous irradiation with femtosecond laser light having an energy density below the laser-induced damage threshold

• Wataru Nomura,
• Tadashi Kawazoe,
• Takashi Yatsui,
• Makoto Naruse and
• Motoichi Ohtsu

Beilstein J. Nanotechnol. 2014, 5, 1334–1340, doi:10.3762/bjnano.5.146

• polished by CMP. Thus, it is effective in reducing the drop in LIDT caused by electric field enhancement induced by the surface structure [5][6]. It has been reported that a dielectric multilayer mirror fabricated by using a silica substrate planarized by this technique exhibited an LIDT that was increased

• the reflectance were originated from the photogenerated carrier in samples D and E. In other words, in Samples D and E, we concluded that the generation probability of photogenerated carriers was higher than in Sample C because electric field enhancement occurred due to laser-induced degradation and

Nanostructure sensitization of transition metal oxides for visible-light photocatalysis

• Hongjun Chen and
• Lianzhou Wang

Beilstein J. Nanotechnol. 2014, 5, 696–710, doi:10.3762/bjnano.5.82

• proposed a new local electric field enhancement mechanism, which is totally different from the charge transfer mechanism proposed by the Tatsuma group. Cronin and co-workers shared a viewpoint similar to that of Ingram et al. and observed enhancements of up to 66 times in the photocatalytic splitting of

• local electric field enhancement. After a comparison of these two different mechanisms, the main difference is the origin of the photogenerated charges. The decision which mechanism takes center stage in the plasmonic enhancement traced back to the question whether there is an overlap in the absorption

• exhibit a much better photocatalytic performance than N-doped TiO2 nanoparticles or TiO2 nanotubes alone. Electromagnetic simulations based on the finite-difference time-domain method provided the theoretical support for this local electric field enhancement mechanism. In contrast to the local electric

Optical near-fields & nearfield optics

• Alfred J. Meixner and
• Paul Leiderer

Beilstein J. Nanotechnol. 2014, 5, 186–187, doi:10.3762/bjnano.5.19

• ” with a length of a few nanometers. This effect of strong near-field enhancement around sharp structures of noble metals has been known from Surface Enhanced Raman Scattering (SERS) for a long time [1]. Yet, the well-controlled tailoring of nanostructures necessary to quantitatively control the optical

• numerous other applications of near-field enhancement, e.g., in biosensors, solar cells and semiconductor quantum dots to name but a few. A challenging question, investigated in this series by Esmann et al. [3], is how light can be most efficiently coupled into sub-wavelength dimensions by means of an

• optical near-fields of nanostructures. Since the field enhancement can be quite large, light-induced local changes of the material can also be utilized to map the spatial distribution of the near-fields as demonstrated by Dickreuter et al. [4]. For this purpose, light-induced local changes of the material

Dye-doped spheres with plasmonic semi-shells: Lasing modes and scattering at realistic gain levels

• Nikita Arnold,
• Boyang Ding,
• Calin Hrelescu and
• Thomas A. Klar

Beilstein J. Nanotechnol. 2013, 4, 974–987, doi:10.3762/bjnano.4.110

• Nikita Arnold Boyang Ding Calin Hrelescu Thomas A. Klar Institute of Applied Physics, Johannes Kepler University, 4040 Linz, Austria 10.3762/bjnano.4.110 Abstract We numerically simulate the compensation of absorption, the near-field enhancement as well as the differential far-field scattering

• the semi-shell with h = 20 nm. Specifically, it shows an l = 1 and an l = 2 mode with resonances in the absorption spectra at 623 and 487 nm, respectively (c.f. Figure 2d). The upper panels in Figure 3 show the field enhancement |E|/E0, in which E0 is the amplitude of the electric field in the

• incident plane wave. The images are cut in the x–z plane, i.e., the plane spanned by the k-vector (z-axis) and the polarization of the electric field (x-axis). A three dimensional representation of the near field enhancement just outside the semi-shell structure is given on the lower left of both panels