A Novel Rectangle Plasmonic Optical Nano-Antenna with Two Protrusions in the Middle Gap

2011 ◽  
Vol 415-417 ◽  
pp. 682-685
Author(s):  
Zong Heng Yuan ◽  
Zhi Wei Liu ◽  
Mei Jie Song ◽  
Jing Huang
Keyword(s):  
Resonant Frequency ◽  
Strong Field ◽  
Visible Region ◽  
Field Enhancement ◽  
Infrared Region ◽  
Good Effect ◽  
Visible Range ◽  
High Quality ◽  
Resonant Frequencies ◽  
New Type

The strong field enhancement of a new type of rectangle plasmonic optic nano-antenna with two protrusions in the middle gap is studied by the comparison with two another common rectangle structures using CST software. The intensity of the new type presented in the paper is about 2.5 times more than its common counterpart, up to about 60V/m in the center of antenna, and the position of peak shifts to visible region (406THz) from infrared region (382THz). Further more, the resonant magnitude in the region of corners of protrusions in the middle gap is somewhat larger than that in center region of antenna, and the resonant frequencies all are controlled in the visible range, about 410THz,the results indicate that the protrusions have a good effect on the performance of antenna. Moreover, when a glass substrate is used, the maximum of field magnitude is about 3 times lager than the same structure without substrate, up to 214 V/m, and the resonant frequency red-shifts to about 359THz, which demonstrates that the substrate plays a important role in the excitation of stronger enhancement. The type presented in the paper has a certain reference for the fabrication of high-quality optical nano-antennas and solar cells etc.

scholarly journals Broadband plasmonic silver nanoflowers for high-performance random lasing covering visible region

Nanophotonics ◽  
2017 ◽  
Vol 6 (5) ◽  
pp. 1151-1160 ◽  
Author(s):  
Qing Chang ◽  
Xiaoyu Shi ◽  
Xuan Liu ◽  
Junhua Tong ◽  
Dahe Liu ◽  
...  
Keyword(s):  
Quality Factor ◽  
High Performance ◽  
Coupling Effect ◽  
Synthesis Method ◽  
Visible Region ◽  
High Quality Factor ◽  
Visible Range ◽  
Random Lasing ◽  
High Quality ◽  
Random Lasers

AbstractMulticolor random lasing has broad potential applications in the fields of imaging, sensing, and optoelectronics. Here, silver nanoflowers (Ag NF) with abundant nanogaps are fabricated by a rapid one-step solution-phase synthesis method and are first proposed as effective broadband plasmonic scatterers to achieve different color random lasing. With abundant nanogaps and spiky tips near the surface and the interparticle coupling effect, Ag NFs greatly enhance the local electromagnetic field and induce broadband plasmonic scattering spectra over the whole visible range. The extremely low working threshold and the high-quality factor for Ag NF-based random lasers are thus demonstrated as 0.24 MW cm−2 and 11,851, respectively. Further, coherent colorful random lasing covering the visible range is realized using the dye molecules oxazine (red), Coumarin 440 (blue), and Coumarin 153 (green), showing high-quality factor of more than 10,000. All these features show that Ag NF are highly efficient scatterers for high-performance coherent random lasing and colorful random lasers.

scholarly journals Enhanced Molecular Infrared Spectroscopy Employing Bilayer Graphene Acoustic Plasmon Resonator

Biosensors ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 431
Author(s):  
Chunchao Wen ◽  
Jie Luo ◽  
Wei Xu ◽  
Zhihong Zhu ◽  
Shiqiao Qin ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Structural Information ◽  
Strong Field ◽  
Field Enhancement ◽  
Infrared Region ◽  
Bilayer Graphene ◽  
Plasmonic Sensors ◽  
Protein Molecules ◽  
Molecular Infrared Spectroscopy ◽  
Graphene Plasmons

Graphene plasmon resonators with the ability to support plasmonic resonances in the infrared region make them a promising platform for plasmon-enhanced spectroscopy techniques. Here we propose a resonant graphene plasmonic system for infrared spectroscopy sensing that consists of continuous graphene and graphene ribbons separated by a nanometric gap. Such a bilayer graphene resonator can support acoustic graphene plasmons (AGPs) that provide ultraconfined electromagnetic fields and strong field enhancement inside the nano-gap. This allows us to selectively enhance the infrared absorption of protein molecules and precisely resolve the molecular structural information by sweeping graphene Fermi energy. Compared to the conventional graphene plasmonic sensors, the proposed bilayer AGP sensor provides better sensitivity and improvement of molecular vibrational fingerprints of nanoscale analyte samples. Our work provides a novel avenue for enhanced infrared spectroscopy sensing with ultrasmall volumes of molecules.

scholarly journals A study on geospatial technology for detecting and mapping of Solenopsis mealybug (Hemiptera: Pseudococcidae) in cotton crop

2016 ◽  
Vol 8 (4) ◽  
pp. 2175-2181 ◽  
Author(s):  
S. K. Singh ◽  
Sujay Dutta ◽  
Nishith Dharaiya
Keyword(s):  
Remote Sensing ◽  
Near Infrared ◽  
Linear Regression Analysis ◽  
Visible Region ◽  
Remote Sensing Data ◽  
Multiple Linear Regression Analysis ◽  
Infrared Region ◽  
Visible Range ◽  
Cotton Crop ◽  
Remote Sensing Indices

Detection of crop stress is one of the major applications of remote sensing in agriculture. Many researchers have confirmed the ability of remote sensing techniques for detection of pest/disease on cotton. The objective of the present study was to evaluate the relation between the mealybug severity and remote sensing indices and development of a model for mapping of mealybug damage using remote sensing indices. The mealybug-infested cotton crop had a significantly lower reflectance (33%) in the near infrared region and higher (14%) in the visible range of the spectrum when compared with the non-infested cotton crop having near infrared and visible region reflectance of 48 % and 9% respectively. Multiple Linear regression analysis showed that there were varying relationships between mealybug severity and spectral vegetation indices, with coefficients of determination (r2) ranging from 0.63 to0.31. Model developed in this study for the mealybug damage assessment in cotton crop yielded significant relationship (r2=0.863) and was applied on satellite data of 21st September 2009 which revealed high severity of mealybug and it was low on 24th September 2010 which confirmed the significance of the model and can be used in the identification of mealybug infested cotton zones. These results indicate that remote sensing data have the potential to distinguish damage by mealybug and quantify its abundance in cotton.

A Process of Glocalisation? Roman Marble Imports and the Rise of Blocked-Out Capitals in Local Stone

2020 ◽  
pp. 33-45
Author(s):  
Matthias Grawehr
Keyword(s):  
Roman Empire ◽  
Eastern Mediterranean ◽  
High Quality ◽  
White Marble ◽  
Aesthetic Preference ◽  
Local Responses ◽  
Global Trend ◽  
Short Period ◽  
New Type ◽  
Local Materials

In the Augustan Age, a new aesthetic preference was propagated in the Roman Empire – the surface of white marble was valued as it symbolised the strength and superiority of the ‘new age’. Soon, an immense trade in high quality marble over land and sea developed to meet the emergent demand. While the development and scale of this trade is well studied, the repercussions that the new aesthetic preference had on the local architectural traditions in areas where no marble was close at hand is not commonly considered. In this contribution, two developments are traced, taking the Corinthian capital as the leitmotif. First, in the short period between c. 40 and 10 BC, patrons would choose imitation of marble in plaster to meet up with the demands of the new standard and to demonstrate their adherence to the Empire. In the second line of development, a different path was taken – a conscious use of local materials which went hand in hand with the development of a new type of capital, the so-called ‘Nabataean blocked-out’ capital. This combination turned into a new vernacular tradition across large parts of the eastern Mediterranean. Both developments were local responses to a new ‘global’ trend and can therefore be viewed as a phenomenon of glocalisation in the Roman Period.

Tuning the Localized Surface Plasmon Resonance of Al-Al2O3 Nanosphere Towards NIR Region by Gold Coating

2020 ◽  
Vol 12 ◽  
Author(s):  
Jyoti Katyal ◽  
Shivani Gautam
Keyword(s):  
Electric Field ◽  
Field Distribution ◽  
Dielectric Layer ◽  
Electric Field Distribution ◽  
Active Material ◽  
Visible Region ◽  
Field Enhancement ◽  
Localized Surface Plasmon ◽  
Sers Substrate ◽  
Al Nanoparticles

Background: A relatively narrow LSPR peak and a strong inter band transition ranging around 800 nm makes Al strongly plasmonic active material. Usually, Al nanoparticles are preferred for UV-plasmonic as the SPR of small size Al nanoparticles locates in deep UV-UV region of the optical spectrum. This paper focused on tuning the LSPR of Al nanostructure towards infrared region by coating Au layer. The proposed structure has Au as outer layer which prevent the further oxidation of Al nanostructure. Methods: The Finite Difference Time Domain (FDTD) and Plasmon Hybridization Theory has been used to evaluated the LSPR and field enhancement of single and dimer Al-Al2O3-Au MDM nanostructure. Results: It is observed that the resonance mode show dependence on the thickness of Al2O3 layer and also on the composition of nanostructure. The Au layered MDM nanostructure shows two peak of equal intensities simultaneously in UV and visible region tuned to NIR region. The extinction spectra and electric field distribution profiles of dimer nanoparticles are compared with monomer to reveal the extent of coupling. The dimer configuration shows higher field enhancement ~107 at 1049 nm. By optimizing the thickness of dielectric layer the MDM nanostructure can be used over UV-visible-NIR region. Conclusion: The LSPR peak shows dependence on the thickness of dielectric layer and also on the composition of nanostructure. It has been observed that optimization of size and thickness of dielectric layer can provide two peaks of equal intensities in UV and Visible region which is advantageous for many applications. The electric field distribution profiles of dimer MDM nanostructure enhanced the field by ~107 in visible and NIR region shows its potential towards SERS substrate. The results of this study will provide valuable information for the optimization of LSPR of Al-Al2O3-Au MDM nanostructure to have high field enhancement.

scholarly journals A MEMS Fabrication Process with Thermal-Oxide Releasing Barriers and Polysilicon Sacrificial Layers for AlN Lamb-Wave Resonators to Achieve fs·Qm > 3.42 × 1012

Micromachines ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 892
Author(s):  
Jicong Zhao ◽  
Zheng Zhu ◽  
Haiyan Sun ◽  
Shitao Lv ◽  
Xingyu Wang ◽  
...  
Keyword(s):  
Resonant Frequency ◽  
Lamb Wave ◽  
Piezoelectric Layer ◽  
Sacrificial Layer ◽  
High Quality ◽  
Micro Electro Mechanical Systems ◽  
Mems Fabrication ◽  
Thermal Oxide ◽  
Series Resonant ◽  
Releasing Process

This paper presents a micro-electro-mechanical systems (MEMS) processing technology for Aluminum Nitride (AlN) Lamb-wave resonators (LWRs). Two LWRs with different frequencies of 402.1 MHz and 2.097 GHz by varying the top interdigitated (IDT) periods were designed and fabricated. To avoid the shortcomings of the uncontrollable etching of inactive areas during the releasing process and to improve the fabrication yield, a thermal oxide layer was employed below the platted polysilicon sacrificial layer, which could define the miniaturized release cavities well. In addition, the bottom Mo electrode that was manufactured had a gentle inclination angle, which could contribute to the growth of the high-quality AlN piezoelectric layer above the Mo layer and effectively prevent the device from breaking. The measured results show that the IDT-floating resonators with 12 μm and 2 μm electrode periods exhibit a motional quality factor (Qm) as high as 4382 and 1633. The series resonant frequency (fs)·Qm values can reach as high as 1.76 × 1012 and 3.42 × 1012, respectively. Furthermore, Al is more suitable as the top IDT material of the AlN LWRs than Au, and can contribute to achieving an excellent electrical performances due to the smaller density, smaller thermo-elastic damping (TED), and larger acoustic impedance difference between Al and AlN.

scholarly journals Gauge invariant canonical symplectic algorithms for real-time lattice strong-field quantum electrodynamics

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Qiang Chen ◽  
Jianyuan Xiao ◽  
Peifeng Fan
Keyword(s):  
Field Theory ◽  
Real Time ◽  
Quantum Electrodynamics ◽  
Symplectic Form ◽  
Strong Field ◽  
Relativistic Quantum ◽  
High Order ◽  
High Quality ◽  
Geometric Structures ◽  
Gauge Invariant

Abstract A class of high-order canonical symplectic structure-preserving geometric algorithms are developed for high-quality simulations of the quantized Dirac-Maxwell theory based strong-field quantum electrodynamics (SFQED) and relativistic quantum plasmas (RQP) phenomena. With minimal coupling, the Lagrangian density of an interacting bispinor-gauge fields theory is constructed in a conjugate real fields form. The canonical symplectic form and canonical equations of this field theory are obtained by the general Hamilton’s principle on cotangent bundle. Based on discrete exterior calculus, the gauge field components are discreted to form a cochain complex, and the bispinor components are naturally discreted on a staggered dual lattice as combinations of differential forms. With pull-back and push-forward gauge covariant derivatives, the discrete action is gauge invariant. A well-defined discrete canonical Poisson bracket generates a semi-discrete lattice canonical field theory (LCFT), which admits the canonical symplectic form, unitary property, gauge symmetry and discrete Poincaré subgroup, which are good approximations of the original continuous geometric structures. The Hamiltonian splitting method, Cayley transformation and symmetric composition technique are introduced to construct a class of high-order numerical schemes for the semi-discrete LCFT. These schemes involve two degenerate fermion flavors and are locally unconditional stable, which also preserve the geometric structures. Admitting Nielsen-Ninomiya theorem, the continuous chiral symmetry is partially broken on the lattice. As an extension, a pair of discrete chiral operators are introduced to reconstruct the lattice chirality. Equipped with statistically quantization-equivalent ensemble models of the Dirac vacuum and non-trivial plasma backgrounds, the schemes are expected to have excellent performance in secular simulations of relativistic quantum effects, where the numerical errors of conserved quantities are well bounded by very small values without coherent accumulation. The algorithms are verified in detail by numerical energy spectra. Real-time LCFT simulations are successfully implemented for the nonlinear Schwinger mechanism induced e-e+ pairs creation and vacuum Kerr effect, where the nonlinear and non-perturbative features captured by the solutions provide a complete strong-field physical picture in a very wide range, which open a new door toward high-quality simulations in SFQED and RQP fields.

Highly luminescent InP-In(Zn)P/ZnSe/ZnS core/shell/shell colloidal quantum dots with tunable emission synthesized based on growth-doping

2021 ◽  
Author(s):  
Cong Shen ◽  
Yan Qing Zhu ◽  
Zixiao Li ◽  
Jingling Li ◽  
Hong Tao ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Near Infrared ◽  
Infrared Region ◽  
Colloidal Quantum Dots ◽  
High Quality ◽  
Promising Alternative ◽  
Lower Toxicity ◽  
Near Infrared Region ◽  
Inp Quantum Dots ◽  
Tunable Emission

InP quantum dots (QDs) are considered as the most promising alternative to Cd-based QDs with the lower toxicity and emission spectrum tunability ranging from visible to near-infrared region. Although high-quality...

scholarly journals Terahertz quantum plasmonics at nanoscales and angstrom scales

Nanophotonics ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 435-451 ◽  
Author(s):  
Taehee Kang ◽  
Young-Mi Bahk ◽  
Dai-Sik Kim
Keyword(s):  
Electron Tunneling ◽  
Strong Field ◽  
Field Enhancement ◽  
Dipole Antenna ◽  
Strong Light ◽  
Metallic Structures ◽  
Terahertz Pulses ◽  
Matter Interaction ◽  
Light Matter Interaction ◽  
Quantum Phenomena

AbstractThrough the manipulation of metallic structures, light–matter interaction can enter into the realm of quantum mechanics. For example, intense terahertz pulses illuminating a metallic nanotip can promote terahertz field–driven electron tunneling to generate enormous electron emission currents in a subpicosecond time scale. By decreasing the dimension of the metallic structures down to the nanoscale and angstrom scale, one can obtain a strong field enhancement of the incoming terahertz field to achieve atomic field strength of the order of V/nm, driving electrons in the metal into tunneling regime by overcoming the potential barrier. Therefore, designing and optimizing the metal structure for high field enhancement are an essential step for studying the quantum phenomena with terahertz light. In this review, we present several types of metallic structures that can enhance the coupling of incoming terahertz pulses with the metals, leading to a strong modification of the potential barriers by the terahertz electric fields. Extreme nonlinear responses are expected, providing opportunities for the terahertz light for the strong light–matter interaction. Starting from a brief review about the terahertz field enhancement on the metallic structures, a few examples including metallic tips, dipole antenna, and metal nanogaps are introduced for boosting the quantum phenomena. The emerging techniques to control the electron tunneling driven by the terahertz pulse have a direct impact on the ultrafast science and on the realization of next-generation quantum devices.

scholarly journals Design and fabrication of a semi-transparent solar cell considering the effect of the layer thickness of MoO3/Ag/MoO3 transparent top contact on optical and electrical properties

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Çağlar Çetinkaya ◽  
Erman Çokduygulular ◽  
Barış Kınacı ◽  
Feyza Güzelçimen ◽  
Yunus Özen ◽  
...  
Keyword(s):  
Solar Cell ◽  
Layer Thickness ◽  
High Performance ◽  
Near Infrared ◽  
Visible Region ◽  
Infrared Region ◽  
Experimental Comparison ◽  
Top Contact ◽  
Cie Chromaticity ◽  
Design And Manufacture

AbstractWe conducted the present study to design and manufacture a semi-transparent organic solar cell (ST-OSC). First, we formed a transparent top contact as MoO3/Ag/MoO3 in a dielectric/metal/dielectric (DMD) structure. We performed the production of an FTO/ZnO/P3HT:PCBM/MoO3/Ag/MoO3 ST-OSC by integrating MoO3/Ag/MoO3 (10/$$d_{m}$$ d m /$$d_{{od}}$$ d od nm) instead of an Ag electrode in an opaque FTO/ZnO/P3HT:PCBM/MoO3/Ag (–/40/130/10/100 nm) OSC, after theoretically achieving optimal values of optical and electrical parameters depending on Ag layer thickness. The transparency decreased with the increase of $$d_{m}$$ d m values for current DMD. Meanwhile, maximum transmittance and average visible transmittance (AVT) indicated the maximum values of over 92% for $$d_{m} ~$$ d m  = 4 and 8 nm, respectively. For ST-OSCs, the absorption and reflectance increased in the visible region by a wavelength of longer than 560 nm and in the whole near-infrared region by increasing $$d_{m}$$ d m up to 16 nm. Moreover, in the CIE chromaticity diagram, we reported a shift towards the D65 Planckian locus for colour coordinates of current ST-OSCs. Electrical analysis indicated the photogenerated current density and AVT values for $$d_{m} = 6$$ d m = 6  nm as 63.30 mA/cm2 and 38.52%, respectively. Thus, the theoretical and experimental comparison of optical and electrical characteristics confirmed that the manufactured structure is potentially conducive for a high-performance ST-OSC.

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