scholarly journals Unveiling radial breathing mode in a particle-on-mirror plasmonic nanocavity

Nanophotonics ◽  
2022 ◽  
Vol 0 (0) ◽  
Author(s):  
Qifa Wang ◽  
Chenyang Li ◽  
Liping Hou ◽  
Hanmou Zhang ◽  
Xuetao Gan ◽  
...  
Keyword(s):  
Local Field ◽  
Near Infrared ◽  
Polarized Light ◽  
Field Enhancement ◽  
Radial Breathing Mode ◽  
Infrared Region ◽  
The Other ◽  
Optical Measurements ◽  
Dark Mode ◽  
Breathing Mode

Abstract Plasmonic radial breathing mode (RBM), featured with radially oscillating charge density, arises from the surface plasmon waves confined in the flat nanoparticles. The zero net dipole moment endows the RBM with an extremely low radiation yet a remarkable intense local field. On the other hand, owing to the dark mode nature, the RBMs routinely escape from the optical measurements, severely preventing their applications in optoelectronics and nanophotonics. Here, we experimentally demonstrate the existence of RBM in a hexagonal Au nanoplate-on-mirror nanocavity using a far-field linear-polarized light source. The polarization-resolved scattering measurements cooperated with the full-wave simulations elucidate that the RBM originates from the standing plasmon waves residing in the Au nanoplate. Further numerical analysis shows the RBM possesses the remarkable capability of local field enhancement over the other dark modes in the same nanocavity. Moreover, the RBM is sensitive to the gap and nanoplate size of the nanocavity, providing a straightforward way to tailor the wavelength of RBM from the visible to near-infrared region. Our approach provides a facile optical path to access to the plasmonic RBMs and may open up a new route to explore the intriguing applications of RBM, including surface-enhanced Raman scattering, enhanced nonlinear effects, nanolasers, biological and chemical sensing.

scholarly journals Towards rational design and optimization of near-field enhancement and spectral tunability of hybrid core-shell plasmonic nanoprobes

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Debadrita Paria ◽  
Chi Zhang ◽  
Ishan Barman
Keyword(s):  
Single Molecule ◽  
Rational Design ◽  
Near Infrared ◽  
Theoretical Calculations ◽  
Near Field ◽  
Field Enhancement ◽  
Infrared Region ◽  
Core Shell ◽  
Optimization Strategy ◽  
Design And Optimization

Abstract In biology, sensing is a major driver of discovery. A principal challenge is to create a palette of probes that offer near single-molecule sensitivity and simultaneously enable multiplexed sensing and imaging in the “tissue-transparent” near-infrared region. Surface-enhanced Raman scattering and metal-enhanced fluorescence have shown substantial promise in addressing this need. Here, we theorize a rational design and optimization strategy to generate nanostructured probes that combine distinct plasmonic materials sandwiching a dielectric layer in a multilayer core shell configuration. The lower energy resonance peak in this multi-resonant construct is found to be highly tunable from visible to the near-IR region. Such a configuration also allows substantially higher near-field enhancement, compared to a classical core-shell nanoparticle that possesses a single metallic shell, by exploiting the differential coupling between the two core-shell interfaces. Combining such structures in a dimer configuration, which remains largely unexplored at this time, offers significant opportunities not only for near-field enhancement but also for multiplexed sensing via the (otherwise unavailable) higher order resonance modes. Together, these theoretical calculations open the door for employing such hybrid multi-layered structures, which combine facile spectral tunability with ultrahigh sensitivity, for biomolecular sensing.

Analytical and Experimental Investigations of Electromagnetic Field Enhancement Among Nanospheres With Varying Spacing

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Li-Hsin Han ◽  
Wei Wang ◽  
Yalin Lu ◽  
R. J. Knize ◽  
Kitt Reinhardt ◽  
...  
Keyword(s):  
Absorption Spectra ◽  
Scattering Theory ◽  
Near Infrared ◽  
Field Enhancement ◽  
Infrared Region ◽  
Mie Scattering ◽  
Interparticle Spacing ◽  
Experimental Investigations ◽  
Gold Nanospheres ◽  
Peak Broadening

A modified Mie scattering theory was used to calculate the enhancement of electromagnetic (EM) field between gold nanospheres. The simulation result showed that the density of EM-energy in the space between neighboring nanospheres increases drastically as the interparticle space decreases. Simulated absorption-spectra also showed a peak-shifting from the visible to the infrared region when decreasing the nanosphere spacing. We used our previous experiment to verify the analytical results; the experiment was conducted by using a photodeformable microshell, which was coated with gold nanospheres. Made of photoshrinkable azobenzene polyelectrolytes, the microshells supported the gold nanospheres and gave the tunability of the interparticle spacing among the nanospheres. Upon irradiation of ultraviolet light, the microshells shrank and reduced the interparticle space. The absorption-spectra of the gradually shrinking microshells showed significant changes; a peak-broadening from the visible to the near-infrared region and a drastically enhanced water-absorption were observed in the experimental spectra. The experimental results confirmed the analytical analysis based on the modified scattering theory.

Surface Plasmon Resonance with Electrospun Nanofibers on Gold Surface

2009 ◽  
Vol 1173 ◽  
Author(s):  
Kazuma Tsuboi ◽  
Hidetoshi Matsumoto ◽  
Mie Minagawa ◽  
Akihiko Tanioka
Keyword(s):  
Surface Plasmon ◽  
Near Infrared ◽  
Polarized Light ◽  
Electrospun Nanofibers ◽  
Gold Surface ◽  
Infrared Region ◽  
Peak Wavelength ◽  
Absorption Bands ◽  
Propagation Length ◽  
Near Infrared Region

AbstractIn this paper we report new excitation method of surface plasmon polariton (SPP) at air/gold interface with electrospun nanofibers. Nanofibers of polyvinylpirrolidone were electrospun onto the surface of a gold film. The observations by scanning electron microscopy and optical microscopy indicated that the average diameters of the nanofibers were about 300 nm and average sizes of pores were about 30-40 μm. Optical response of the nanofibers on gold surface was investigated by polarized reflection absorption spectroscopy (RAS). The RAS spectrum with p-polarized light showed two absorption bands while the spectrum with s-polarized light only one band. One is a band at about 520 nm that also found in the spectrum with s-polarized light. Another is a broad band in the near-infrared region which found only with p-polarized light. The peak intensity of the latter band increases with increase of incident angle of the polarized light and the peak wavelength of the band shifted to longer wavelength. These responses suggested that SPP at air/gold interface was excited with the scattering light from the electrospun nanofibers. We also found that the peak wavelength of the absorption band in near-infrared region changed with the increase of the amount of the nanofibers. This may be due to the fact that the sizes of the pores on gold surface became smaller than the propagation length of SPP, which resulted in scattering and interference of SPP.

scholarly journals Experimental verification of asymmetric transmission in continuous omega-shaped metamaterials

RSC Advances ◽  
2018 ◽  
Vol 8 (67) ◽  
pp. 38556-38561 ◽  
Author(s):  
Ying-Hua Wang ◽  
Inki Kim ◽  
Ren-Chao Jin ◽  
Heonyeong Jeong ◽  
Jia-Qi Li ◽  
...  
Keyword(s):  
Experimental Verification ◽  
Near Infrared ◽  
Polarized Light ◽  
Infrared Region ◽  
Asymmetric Transmission ◽  
Linearly Polarized ◽  
Near Infrared Region

A bi-layer continuous omega-shaped metamaterial was proposed and fabricated to measure the asymmetric transmission (AT) effect of a linearly polarized light at near-infrared region.

scholarly journals High-Performance Asymmetric Optical Transmission Based on a Dielectric–Metal Metasurface

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2410
Author(s):  
Wenbing Liu ◽  
Lirong Huang ◽  
Jifei Ding ◽  
Chenkai Xie ◽  
Yi Luo ◽  
...  
Keyword(s):  
High Performance ◽  
Optical Transmission ◽  
Near Infrared ◽  
Contrast Ratio ◽  
Polarized Light ◽  
Infrared Region ◽  
Optical Systems ◽  
Asymmetric Transmission ◽  
Linearly Polarized ◽  
Transmittance Peak

Asymmetric optical transmission plays a key role in many optical systems. In this work, we propose and numerically demonstrate a dielectric–metal metasurface that can achieve high-performance asymmetric transmission for linearly polarized light in the near-infrared region. Most notably, it supports a forward transmittance peak (with a transmittance of 0.70) and a backward transmittance dip (with a transmittance of 0.07) at the same wavelength of 922 nm, which significantly enhances operation bandwidth and the contrast ratio between forward and backward transmittances. Mechanism analyses reveal that the forward transmittance peak is caused by the unidirectional excitation of surface plasmon polaritons and the first Kerker condition, whereas the backward transmittance dip is due to reflection from the metal film and a strong toroidal dipole response. Our work provides an alternative and simple way to obtain high-performance asymmetric transmission devices.

scholarly journals Monolithic integration of visible GaAs and near-infrared InGaAs for multicolor photodetectors by using high-throughput epitaxial lift-off toward high-resolution imaging systems

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Dae-Myeong Geum ◽  
SangHyeon Kim ◽  
Seong Kwang Kim ◽  
SooSeok Kang ◽  
JiHoon Kyhm ◽  
...  
Keyword(s):  
High Resolution ◽  
High Throughput ◽  
Near Infrared ◽  
Optical Loss ◽  
Infrared Region ◽  
Optical Measurements ◽  
Bonding Layer ◽  
Infrared Band ◽  
Absorption Region ◽  
Lift Off

AbstractIn this study, multicolor photodetectors (PDs) fabricated by using bulk p-i-n-based visible GaAs and near-infrared InGaAs structures were monolithically integrated through a high-throughput epitaxial lift-off (ELO) process. To perform multicolor detection in integrated structures, GaAs PDs were transferred onto InGaAs PDs by using a Y2O3 bonding layer to simultaneously detect visible and near-infrared photons and minimize the optical loss. As a result, it was found that the GaAs top PD and InGaAs bottom PD were vertically aligned without tilting in x-ray diffraction (XRD) measurement. A negligible change in the dark currents for each PD was observed in comparison with reference PDs through electrical characterization. Furthermore, through optical measurements and simulation, photoresponses were clearly revealed in the visible and near-infrared band for the material’s absorption region, respectively. Finally, we demonstrated the simultaneous multicolor detection of the visible and near-infrared region,which implies individual access to each PD without mutual interference. These results are a significant improvement for the fabrication of multicolor PDs that enables the formation of bulk-based multicolor PDs on a single substrate with a high pixel density and nearly perfect vertical alignment for high-resolution multicolor imaging.

scholarly journals Demonstration of Improved Charge Transfer in Graphene/Au Nanorods Plasmonic Hybrids Stabilized by Benzyl Thiol Linkers

2016 ◽  
Vol 2016 ◽  
pp. 1-6
Author(s):  
Giuseppe Valerio Bianco ◽  
Maria Michela Giangregorio ◽  
Maria Losurdo ◽  
Alberto Sacchetti ◽  
Pio Capezzuto ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Near Infrared ◽  
Chemical Vapor ◽  
Infrared Region ◽  
Optical Measurements ◽  
Electrical Measurements ◽  
Effective Electron ◽  
Au Nanorods ◽  
Cvd Graphene ◽  
Enhanced Absorption

Hybrids based on graphene decorated with plasmonic gold (Au) nanostructures are being investigated as possible materials combination to add to graphene functionalities of tunable plasmon resonance and enhanced absorption at selected wavelength in the visible-near-infrared region of the spectrum. Here, we report a solution drop-casting approach for fabricating stable hybrids based on chemical vapor deposition (CVD) graphene and Au nanorods, which are able to activate effective charge transfer from graphene. We demonstrate that CVD graphene functionalization by benzyl thiol (BZT) provides the linker to strong anchoring, via S-Au bonds, Au nanorods to graphene. Optical measurements by spectroscopic ellipsometry give evidence of the introduction of plasmon resonances at 1.85 and 2.25 eV in the Au nanorods/BZT/graphene hybrids, which enable surface enhanced Raman scattering (SERS) detection. Furthermore, an effective electron transfer from graphene to Au nanorods, resulting in an enhancement of p-type doping of graphene with a consequent decrease of its sheet resistance, is probed by Raman spectroscopy and corroborated by electrical measurements.

Discotic liquid crystals of transition metal complexes, 55: Novel chlorine-substituted phthalocyanine derivatives showing mesomorphism and low HOMO energy level

2018 ◽  
Vol 22 (01n03) ◽  
pp. 32-45 ◽  
Author(s):  
Masashi Yatabe ◽  
Akio Kajitani ◽  
Mikio Yasutake ◽  
Kazuchika Ohta
Keyword(s):  
Energy Level ◽  
Near Infrared ◽  
Infrared Region ◽  
Optical Microscope ◽  
The Other ◽  
Homo Energy ◽  
Chlorine Atoms ◽  
Other Hand ◽  
Temperature Variable ◽  
Homo Energy Level

We have synthesized a series of novel phthalocyaninato copper(II) (abbreviated as PcCu) compounds, 1,4,8,11,15,18,22,25-octakisalkoxy-2,3,9,10,16,17,23,24-octachloro-phthalocyaninato copper(II) (abbreviated as ([Formula: see text]-C[Formula: see text]O)[Formula: see text]-Cl)[Formula: see text]PcCu (4a–4d): [Formula: see text] 6 (a), 8 (b), 10 (c) and 12 (d)) and, for comparison, another series of PcCu compounds, 1,4,8,11,15,18,22,25-octakisalkoxyphthalocyaninato copper(II) (abbreviated as ([Formula: see text]-C[Formula: see text]O)[Formula: see text]PcCu (1a–1d)). The PcCu derivatives 1a–1d are substituted by alkoxy chains only at the [Formula: see text] positions (1,4,8,11,15,18,22,25). On the other hand, the PcCu derivatives 4a–4d are substituted by alkoxy chains at the [Formula: see text] positions and chlorine atoms at the [Formula: see text] positions (2,3,9,10,16,17,23,24). We have investigated the influence of chlorine atoms substituted at the [Formula: see text] positions of the Pc ring on mesomorphism, spectroscopic and electronic properties for these two series of PcCu derivatives 1 and 4 by using a polarizing optical microscope, DSC, temperature-variable small angle X-ray diffractometer, a UV-Vis spectrophotometer and cyclic voltammetry. Each of the derivatives 1a–1d is crystalline without showing mesomorphism. On the other hand, each of the chlorine-substituted PcCu derivatives 4a–4d shows plural phase transitions, and the longer chain-substituted PcCu derivatives 4c–4d show a rectangular ordered columnar [Col[Formula: see text](P2m)] mesophase. Furthermore, we have revealed that each of the PcCu derivatives 4a–4d shows a Q-band in the near-infrared region and a lower HOMO energy level than conventional phthalocyanine derivatives.

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