Active Manipulation of Fano Resonance at Visible and Near-Infrared Wavelengths in Metal Plasmonic Nanodevices Using Graphene

Abstract Active manipulation of Fano resonance at visible and near-IR wavelengths in metal nanodevices is one of the important challenges for applications such as chemical and biological sensing. Here, we theoretically research an active manipulation of Fano resonance at visible and near-IR wavelengths in gold plasmonic nanodevices with graphene. The surface plasmon resonance of the gold plasmonic nanodevice with graphene has three resonance peaks, and this can be explained by the distribution of the electric field in the nanodevice. The Fano resonance wavelength of the gold plasmonic nanodevice with graphene has a significant blue-shift compared with the gold nanodevices without graphene. Moreover, the Fano resonance dependens on the length and position of Au nanorods and the environment refractive index. The figure of merit of the gold nanodevice with graphene can be as high as 41.3, which makes the system suitable for high sensitivity applications. Finally, we actively manipulate the absorption spectrum and the reflected light phase through changing the Fermi energy of graphene. These results suggest an original method for the design of an actively manipulated Fano resonance nanodevice.

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Optical Properties of Near-Infrared Cyanine Dye Molecules Adsorbed on Silver Nanoparticles

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.457-458.1250 ◽

2012 ◽

Vol 457-458 ◽

pp. 1250-1253

Author(s):

Tao Meng ◽

Chun Mei Zhang ◽

Mi Dan Li ◽

Chun Liu ◽

Shan Shan Meng

Keyword(s):

Silver Nanoparticles ◽

Optical Properties ◽

Optical Property ◽

Silver Nanoparticle ◽

Near Infrared ◽

Blue Shift ◽

Cyanine Dye ◽

Dye Molecules ◽

Near Ir ◽

Spectral Peaks

The optical property of near-infrared cyanine dye adsorbed on silver nanopaticals has been studied by means of UV-Vis spectrophotometer. The adsorption of near-IR cyanine dye on silver nanopaticles was highly dependent on the concentration of silver nanoparticles. As a result, in the UV-Vis spectra, it was shown that the “red-shift”, as silver nanoparticles size, increased and the “blue-shift”, as concentration of silver nanoparticle increased as well. The adsorbed spectral peaks of near-infrared cyanine dye disappeared as concentration of silver nanoparticles increased.

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Research on Fano Resonance Sensing Characteristics Based on Racetrack Resonant Cavity

Micromachines ◽

10.3390/mi12111359 ◽

2021 ◽

Vol 12 (11) ◽

pp. 1359

Author(s):

Yaxin Yu ◽

Jiangong Cui ◽

Guochang Liu ◽

Rongyu Zhao ◽

Min Zhu ◽

...

Keyword(s):

Integrated Circuits ◽

Fano Resonance ◽

Near Infrared ◽

Resonant Cavity ◽

High Sensitivity ◽

Infrared Region ◽

Optical Integrated Circuits ◽

Element Simulation ◽

Metal Insulator Metal ◽

Sensing Characteristics

To reduce the loss of the metal–insulator–metal waveguide structure in the near-infrared region, a plasmonic nanosensor structure based on a racetrack resonant cavity is proposed herein. Through finite element simulation, the transmission spectra of the sensor under different size parameters were analyzed, and its influence on the sensing characteristics of the system was examined. The analysis results show that the structure can excite the double Fano resonance, which has a distinctive dependence on the size parameters of the sensor. The position and line shape of the resonance peak can be adjusted by changing the key parameters. In addition, the sensor has a higher sensitivity, which can reach 1503.7 nm/RIU when being used in refractive index sensing; the figure of merit is 26.8, and it can reach 0.75 nm/°C when it is used in temperature sensing. This structure can be used in optical integrated circuits, especially high-sensitivity nanosensors.

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Plasmons driven by single electrons in graphene nanoislands

Nanophotonics ◽

10.1515/nanoph-2012-0035 ◽

2013 ◽

Vol 2 (2) ◽

pp. 139-151 ◽

Cited By ~ 35

Author(s):

Alejandro Manjavacas ◽

Sukosin Thongrattanasiri ◽

F. Javier García de Abajo

Keyword(s):

Cross Sections ◽

Near Infrared ◽

Near Field ◽

Field Enhancement ◽

High Sensitivity ◽

Quantum Mechanical ◽

Single Electrons ◽

Electromagnetic Simulations ◽

Highly Sensitive ◽

Infrared Wavelengths

AbstractPlasmons produce large confinement and enhancement of light that enable applications as varied as cancer therapy and catalysis. Adding to these appealing properties, graphene has emerged as a robust, electrically tunable material exhibiting plasmons that strongly depend on the density of doping charges. Here we show that adding a single electron to a graphene nanoisland consisting of hundreds or thousands of atoms switches on infrared plasmons that were previously absent from the uncharged structure. Remarkably, the addition of each further electron produces a dramatic frequency shift. Plasmons in these islands are shown to be tunable down to near infrared wavelengths. These phenomena are highly sensitive to carbon edges. Specifically, armchair nanotriangles display sharp plasmons that are associated with intense near-field enhancement, as well as absorption cross-sections exceeding the geometrical area occupied by the graphene. In contrast, zigzag triangles do not support these plasmons. Our conclusions rely on realistic quantum-mechanical calculations, which are in ostensible disagreement with classical electromagnetic simulations, thus revealing the quantum nature of the plasmons. This study shows a high sensitivity of graphene nanoislands to elementary charges, therefore emphasizing their great potential for novel nano-optoelectronics applications.

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Westbrook's Molecular Gun: Discovery of Near-Infrared Microstructures and Molecular Bullets in AFGL 618

Symposium - International Astronomical Union ◽

10.1017/s0074180900208279 ◽

2003 ◽

Vol 209 ◽

pp. 122-122

Author(s):

Toshiya Ueta ◽

David Fong ◽

Margaret Meixner

Keyword(s):

Planetary Nebula ◽

Near Infrared ◽

Line Emission ◽

Infrared Camera ◽

High Sensitivity ◽

Light Component ◽

Emission Component ◽

Near Ir ◽

Resolution Observation ◽

Circumstellar Shell

We present high-sensitivity near-IR images of a carbon-rich proto-planetary nebula, AFGL 618, obtained with the Infrared Camera and Spectrograph (IRCS) mounted on the 8.2m Subaru Telescope. The deep near-IR images have revealed “bullets” and “horns” extending farther out from the edges of the previously known bipolar nebulosities that consist of dust-scattered star light component and shock-excited line emission component. That these bullets and horns represent the positions from which [Fe II] IR lines arise is strongly suggested from the spatial coincidence between these near-IR microstructures and the optical collimated outflow structure observed by the recent HST/WFPC2 imaging, together with the previous detection of shock-excited, forbidden IR lines of atomic species at those locations. At these positions of the near-IR mincrostructures, we have also discovered CO clumps moving at > 200 km s-1 from our re-analysis of the existing 12CO J = 1 – 0 data obtained with the Berkeley-Illinois-Maryland Association (BIMA) interferometer array. These findings indicate that fast-moving CO clumps seem to be impinging upon the surrounding ambient circumstellar shell, thereby causing shocked emission regions which manifest themselves as the near-IR microstructures at the shock interface. To deepen our understanding of the connection between the near-IR microstructures and the CO outflow structure, we are currently conducting higher resolution observation in CO lines with the BIMA array.

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The VLT Interferometer

Symposium - International Astronomical Union ◽

10.1017/s0074180900107454 ◽

1994 ◽

Vol 158 ◽

pp. 143-150

Author(s):

T. R. Bedding ◽

J. M. Beckers ◽

M. Faucherre ◽

N. Hubin ◽

B. Koehler ◽

...

Keyword(s):

Adaptive Optics ◽

Near Infrared ◽

High Sensitivity ◽

Large Telescope ◽

Wavefront Correction ◽

Wavefront Aberrations ◽

Very Large Telescope ◽

Infrared Wavelengths ◽

Very High

One of the observing modes available with the ESO Very Large Telescope will be coherent combination of the light received by up to four 8 m unit telescopes and several 1.8 m auxiliary telescopes. The location of the main telescopes is fixed, while auxiliary telescopes can be moved among some 30 observing stations. The locations of these stations were chosen to augment the (u, v) coverage of the unit telescopes as well as to function as an independent interferometric array.The 8 m telescopes will be equipped with adaptive optics to correct for seeing-induced wavefront aberrations. This wavefront correction will be complete at near-infrared wavelengths, giving the interferometer very high sensitivity in this spectral regime. This paper gives a brief description of the VLT Interferometer and an update on its status.

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Time variability in the bipolar scattered light nebula of L1527 IRS: a possible warped inner disk

Astronomy and Astrophysics ◽

10.1051/0004-6361/201935419 ◽

2019 ◽

Vol 626 ◽

pp. A51

Author(s):

Brian T. Cook ◽

John J. Tobin ◽

Michael F. Skrutskie ◽

Matthew J. Nelson

Keyword(s):

Surface Brightness ◽

Near Infrared ◽

Scattered Light ◽

Time Variability ◽

Time Varying ◽

Spatially Resolved ◽

Near Ir ◽

Low Mass ◽

Infrared Wavelengths ◽

Brightness Variability

Context. The bipolar outflows associated with low-mass protostars create cavities in the infalling envelope. These cavities are illuminated by the central protostar and inner disk, creating a bipolar scattered light nebula at near-infrared and mid-infrared wavelengths. The variability of the scattered light nebula in both total intensity and intensity as a function of position in the scattered light nebula can provide important insights into the structure of the inner disk that cannot be spatially resolved. Aims. We aim to determine the likelihood that a warped inner disk is the origin of the surface brightness variability in the bipolar scattered light nebula associated with L1527 IRS. Methods. We present results from near-IR imaging conducted over the course of seven years, with periods of monthly cadence monitoring. We used Monte Carlo radiative transfer models to interpret the observations. Results. We find a time varying, asymmetrical brightness in the scattered light nebulae within the outflow cavities of the protostar. Starting in 2007, the surface brightnesses of the eastern and western outflow cavities were roughly symmetric. Then, in 2009, the surface brightnesses of the cavities were found to be asymmetric, with a substantial increase in surface brightness and a larger increase in the eastern outflow cavity. More regular monitoring was conducted from 2011 to 2014, revealing a rotating pattern of surface brightness variability in addition to a slow change of the eastern and western outflow cavities toward symmetry, but still not as symmetric as observed in 2007. We find that an inner disk warp is a feasible mechanism to produce the rotating pattern of surface brightness variability.

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Plasmon-assisted interaction of Si with light, for cancer hyperthermia and electromagnetic energy harvest

The European Physical Journal Applied Physics ◽

10.1051/epjap/2020200071 ◽

2020 ◽

Vol 92 (2) ◽

pp. 20101

Author(s):

Behnam Kheyraddini Mousavi ◽

Morteza Rezaei Talarposhti ◽

Farshid Karbassian ◽

Arash Kheyraddini Mousavi

Keyword(s):

Silicon Nanowires ◽

Metallic Nanoparticles ◽

Near Infrared ◽

Optical Transition ◽

Electromagnetic Energy ◽

Energy Harvest ◽

Absorption Enhancement ◽

Ir Absorption ◽

Absorption Mechanism ◽

Near Ir

Metal-assisted chemical etching (MACE) is applied for fabrication of silicon nanowires (SiNWs). We have shown the effect of amorphous sheath of SiNWs by treating the nanowires with SF6 and the resulting reduction of absorption bandwidth, i.e. making SiNWs semi-transparent in near-infrared (IR). For the first time, by treating the fabricated SiNWs with copper containing HF∕H2O2∕H2O solution, we have generated crystalline nanowires with broader light absorption spectrum, up to λ = 1 μm. Both the absorption and photo-luminescence (PL) of the SiNWs are observed from visible to IR wavelengths. It is found that the SiNWs have PL at visible and near Infrared wavelengths, which may infer presence of mechanisms such as forbidden gap transitions other can involvement of plasmonic resonances. Non-radiative recombination of excitons is one of the reasons behind absorption of SiNWs. Also, on the dielectric metal interface, the absorption mechanism can be due to plasmonic dissipation or plasmon-assisted generation of excitons in the indirect band-gap material. Comparison between nanowires with and without metallic nanoparticles has revealed the effect of nanoparticles on absorption enhancement. The broader near IR absorption, paves the way for applications like hyperthermia of cancer while the optical transition in near IR also facilitates harvesting electromagnetic energy at a broad spectrum from visible to IR.

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Electromechanically reconfigurable optical nano-kirigami

Nature Communications ◽

10.1038/s41467-021-21565-x ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Shanshan Chen ◽

Zhiguang Liu ◽

Huifeng Du ◽

Chengchun Tang ◽

Chang-Yin Ji ◽

...

Keyword(s):

Near Infrared ◽

Large Range ◽

Three Dimensional ◽

High Contrast ◽

Si Substrate ◽

High Modulation ◽

Gold Nanostructure ◽

Infrared Wavelengths ◽

On Chip ◽

Nano Electromechanical System

AbstractKirigami, with facile and automated fashion of three-dimensional (3D) transformations, offers an unconventional approach for realizing cutting-edge optical nano-electromechanical systems. Here, we demonstrate an on-chip and electromechanically reconfigurable nano-kirigami with optical functionalities. The nano-electromechanical system is built on an Au/SiO2/Si substrate and operated via attractive electrostatic forces between the top gold nanostructure and bottom silicon substrate. Large-range nano-kirigami like 3D deformations are clearly observed and reversibly engineered, with scalable pitch size down to 0.975 μm. Broadband nonresonant and narrowband resonant optical reconfigurations are achieved at visible and near-infrared wavelengths, respectively, with a high modulation contrast up to 494%. On-chip modulation of optical helicity is further demonstrated in submicron nano-kirigami at near-infrared wavelengths. Such small-size and high-contrast reconfigurable optical nano-kirigami provides advanced methodologies and platforms for versatile on-chip manipulation of light at nanoscale.

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High Sensitivity Plasmonic Sensor Based on Fano Resonance with Inverted U-Shaped Resonator

Sensors ◽

10.3390/s21041164 ◽

2021 ◽

Vol 21 (4) ◽

pp. 1164

Author(s):

Gongli Xiao ◽

Yanping Xu ◽

Hongyan Yang ◽

Zetao Ou ◽

Jianyun Chen ◽

...

Keyword(s):

Fano Resonance ◽

Figure Of Merit ◽

High Sensitivity ◽

Refractive Index Sensor ◽

Multimode Interference ◽

Geometrical Parameters ◽

The Finite Element Method ◽

Plasmonic Sensor ◽

Coupled Mode ◽

Plasmonic Nanosensor

Herein, we propose a tunable plasmonic sensor with Fano resonators in an inverted U-shaped resonator. By manipulating the sharp asymmetric Fano resonance peaks, a high-sensitivity refractive index sensor can be realized. Using the multimode interference coupled-mode theory and the finite element method, we numerically simulate the influences of geometrical parameters on the plasmonic sensor. Optimizing the structure parameters, we can achieve a high plasmonic sensor with the maximum sensitivity for 840 nm/RIUand figure of merit for 3.9 × 105. The research results provide a reliable theoretical basis for designing high sensitivity to the next generation plasmonic nanosensor.

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