Optothermally Tuned Charge Transfer Plasmons in Au-Ge2Sb2Te5 Core-Shell Assemblies

MRS Advances ◽  
2018 ◽  
Vol 3 (33) ◽  
pp. 1919-1924
Author(s):  
Burak Gerislioglu ◽  
Arash Ahmadivand ◽  
Nezih Pala
Keyword(s):  
Charge Transfer ◽  
Infrared Spectrum ◽  
Near Infrared ◽  
Core Shell ◽  
Morphological Variations ◽  
Data Routing ◽  
Nanophotonic Devices ◽  
Resonance Modes ◽  
Near Infrared Spectra ◽  
Amorphous Dielectric

ABSTRACTTunable plasmonic resonances across the visible and near infrared spectra have provided novel ways to develop next-generation nanophotonic devices. Here, by utilizing optothermally controllable phase-changing material (PCM), we studied highly tunable charge transfer plasmon (CTP) resonance modes. To this end, we have designed a two-member dimer assembly including gold cores and Ge2Sb2Te5 (GST) shells in distant, touching, and overlapping conditions. We successfully demonstrated that toggling between amorphous (dielectric) and crystalline (conductive) phases of GST allows for achieving tunable dipolar and CTP resonances along the near-infrared spectrum. The proposed dimer structures can help forming optothermally controlled devices without further morphological variations in the geometry of the design, and having strong potential for advanced plasmon modulation and fast data routing.

scholarly journals Detecting the signatures of helium in type Iax supernovae

2019 ◽  
Vol 622 ◽  
pp. A102 ◽  
Author(s):  
M. R. Magee ◽  
S. A. Sim ◽  
R. Kotak ◽  
K. Maguire ◽  
A. Boyle
Keyword(s):  
Infrared Spectrum ◽  
Optical Spectrum ◽  
Near Infrared ◽  
Spectral Features ◽  
Helium Abundance ◽  
Band Maximum ◽  
Helium Content ◽  
Near Infrared Spectra ◽  
Infrared Wavelengths ◽  
Helium Star

Recent studies have argued that the progenitor system of type Iax supernovae must consist of a carbon-oxygen white dwarf accreting from a helium star companion. Based on existing explosion models invoking the pure deflagration of carbon-oxygen white dwarfs, we investigate the likelihood of producing spectral features due to helium in type Iax supernovae. From this scenario, we select those explosion models producing ejecta and 56Ni masses that are broadly consistent with those estimated for type Iax supernovae (0.014–0.478 M⊙ and ∼0.003–0.183 M⊙, respectively). To this end, we present a series of models of varying luminosities (−18.4 ≲ MV ≲ −14.5 mag) with helium abundances accounting for up to ∼36% of the ejecta mass, and covering a range of epochs beginning a few days before B-band maximum to approximately two weeks after maximum. We find that the best opportunity for detecting He I features is at near-infrared wavelengths, and in the post-maximum spectra of the fainter members of this class. We show that the optical spectrum of SN 2007J is potentially consistent with a large helium content (a few 10−2 M⊙), but argue that current models of accretion and material stripping from a companion struggle to produce compatible scenarios. We also investigate the presence of helium in all objects with near-infrared spectra. We show that SNe 2005hk, 2012Z, and 2015H contain either no helium or their helium abundances are constrained to much lower values (≲10−3 M⊙). For the faint type Iax supernova, SN 2010ae, we tentatively identify a small helium abundance from its near-infrared spectrum. Our results demonstrate the differences in helium content among type Iax supernovae, perhaps pointing to different progenitor channels. Either SN 2007J is an outlier in terms of its progenitor system, or it is not a true member of the type Iax supernova class.

scholarly journals Broadband Plasmonic Nanopolarizer Based on Different Surface Plasmon Resonance Modes in a Silver Nanorod

Crystals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 447
Author(s):  
Junxi Zhang ◽  
Lei Hu ◽  
Zhijia Hu ◽  
Yongqing Wei ◽  
Wei Zhang ◽  
...  
Keyword(s):  
Electric Fields ◽  
Near Infrared ◽  
Near Field ◽  
Resonant Cavity ◽  
Transverse Magnetic ◽  
Wave Mode ◽  
Fdtd Simulation ◽  
Nanophotonic Devices ◽  
Resonance Modes ◽  
Polarization Characteristics

Conventional polarizers including sheet, wire-grid, prism, and Brewster-angle type polarizers are not easily integrated with photonic circuits. Polarizing elements on the nanoscale are indispensable for integrated all-optical nanophotonic devices. Here, we propose a plasmonic nanopolarizer based on a silver nanorod. The polarization characteristics result from the excitation of different resonance modes of localized surface plasmons (LSPs) at different wavelengths. Furthermore, the polarization characteristics in near field regions have been demonstrated by the electric field distribution of the nanorod based on finite-difference time-domain (FDTD) simulation, indicating a strong local resonant cavity with a standing wave mode for transverse electric (TE) polarization and weak electric fields distributed for transverse magnetic (TM) polarization. The nanopolarizer can efficiently work in the near field region, exhibiting a nanopolarization effect. In addition, very high extinction ratios and extremely low insertion losses can be achieved. Particularly, the nanopolarizer can work in a broadband from visible to near-infrared wavelengths, which can be tuned by changing the aspect ratio of the nanorod. The plasmonic nanopolarizer is a promising candidate for potential applications in the integration of nanophotonic devices and circuits.

Near Infrared Spectra of Water in Aqueous Solutions of Organic Salts. A Solvation Study of Bu4NBr, , and

1971 ◽  
Vol 49 (12) ◽  
pp. 2008-2013 ◽  
Author(s):  
C. Jolicoeur ◽  
Nguyen Dinh The ◽  
A. Cabana
Keyword(s):  
Infrared Spectrum ◽  
Aqueous Solutions ◽  
Infrared Spectra ◽  
Near Infrared ◽  
The Other ◽  
Simple Analysis ◽  
Organic Salts ◽  
Solvent Interactions ◽  
Near Infrared Spectra ◽  
Qualitative Similarity

The near-infrared spectrum of water at various temperatures and in aqueous solutions of Bu4NBr, [Formula: see text], and [Formula: see text] is studied in the region 0.8–1.2 µ. The spectra are recorded differentially with respect to water by varying the cell lengths as to take into account density changes or the volume occupied by the solutes. A simple analysis of these spectra illustrates the qualitative similarity between the effects of the Bu4N+ ion and that of a temperature decrement on the spectrum of water. On the other hand striking differences are observed in the differential spectra obtained with Bu4NBr and the phenyl substituted: salts. Further differences are exhibited in the relative solute-solvent interactions of [Formula: see text] and [Formula: see text].

Near Infrared Spectrum Based Color Detection Modeling in Printing

2011 ◽  
Vol 403-408 ◽  
pp. 1740-1743
Author(s):  
Mei Chen ◽  
Xin Liu ◽  
Jian Lin ◽  
Zheng Lei Wen
Keyword(s):  
Infrared Spectrum ◽  
Least Squares ◽  
Partial Least Squares ◽  
Near Infrared ◽  
Training Sample ◽  
Support Vector ◽  
Training Sample Size ◽  
Near Infrared Spectra ◽  
Print Color ◽  
Near Infrared Spectrum

It exits nonlinear relationship between near infrared spectrum and print color. We could make use of diffuse spectrometric to get the near infrared spectra of print sample. The traditional method is using the partial least squares (PLS) to establish relation mathematical model, but the partial least squares (PLS) has the problem of low accuracy and bigger training sample size. The least squares support vector machine (LS-SVM) is presented in the paper to establish prediction model of print color. The result shows that the LS-SVM model has higher accuracy than PLS model.

Rapid Determining Contents of the Rhubarb Anthraquinones Compounds by Support Vector Machines Modeling based on Near Infrared Spectra

2020 ◽  
Vol 16 ◽  
Author(s):  
Linqi Liu ◽  
JInhua Luo ◽  
Chenxi Zhao ◽  
Bingxue Zhang ◽  
Wei Fan ◽  
...  
Keyword(s):  
Infrared Spectra ◽  
Near Infrared ◽  
Mean Squared Error ◽  
Rapid Determination ◽  
Partial Least Square ◽  
Least Square ◽  
Support Vector ◽  
Near Infrared Spectra ◽  
Aloe Emodin ◽  
Relative Differences

BACKGROUND: Measuring medicinal compounds to evaluate their quality and efficacy has been recognized as a useful approach in treatment. Rhubarb anthraquinones compounds (mainly including aloe-emodin, rhein, emodin, chrysophanol and physcion) are its main effective components as purgating drug. In the current Chinese Pharmacopoeia, the total anthraquinones content is designated as its quantitative quality and control index while the content of each compound has not been specified. METHODS: On the basis of forty rhubarb samples, the correlation models between the near infrared spectra and UPLC analysis data were constructed using support vector machine (SVM) and partial least square (PLS) methods according to Kennard and Stone algorithm for dividing the calibration/prediction datasets. Good models mean they have high correlation coefficients (R2) and low root mean squared error of prediction (RMSEP) values. RESULTS: The models constructed by SVM have much better performance than those by PLS methods. The SVM models have high R2 of 0.8951, 0.9738, 0.9849, 0.9779, 0.9411 and 0.9862 that correspond to aloe-emodin, rhein, emodin, chrysophanol, physcion and total anthraquinones contents, respectively. The corresponding RMSEPs are 0.3592, 0.4182, 0.4508, 0.7121, 0.8365 and 1.7910, respectively. 75% of the predicted results have relative differences being lower than 10%. As for rhein and total anthraquinones, all of the predicted results have relative differences being lower than 10%. CONCLUSION: The nonlinear models constructed by SVM showed good performances with predicted values close to the experimental values. This can perform the rapid determination of the main medicinal ingredients in rhubarb medicinal materials.

scholarly journals Nanopatterned metallic transparent electrodes for the near-infrared spectrum

AIP Advances ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 045005
Author(s):  
Aliaksandr Hubarevich ◽  
Mikita Marus ◽  
Yauhen Mukha ◽  
Aliaksandr Smirnov ◽  
Xiao Wei Sun
Keyword(s):  
Infrared Spectrum ◽  
Near Infrared ◽  
Transparent Electrodes ◽  
Near Infrared Spectrum

An electrically driven whispering gallery polariton microlaser

Nanoscale ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 5448-5459
Author(s):  
Mingming Jiang ◽  
Peng Wan ◽  
Kai Tang ◽  
Maosheng Liu ◽  
Caixia Kan
Keyword(s):  
Infrared Spectrum ◽  
Near Infrared ◽  
Whispering Gallery ◽  
Near Infrared Spectrum

An electrically driven whispering gallery polariton microlaser composed of a ZnO:Ga microwire and a p-GaAs template was fabricated. Its working characteristics of polariton lasing in the near-infrared spectrum were demonstrated.

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