scholarly journals Near-field Strong Plasmonic Resonances in Bi1.5Sb0.5Te1.8Se1.2 Topological Insulator Film

2021 ◽  
Author(s):  
Baoshan Guo ◽  
Huan Yao ◽  
Ningwei Zhan ◽  
Lan Jiang
Keyword(s):  
Topological Insulator ◽  
Electromagnetic Waves ◽  
Near Infrared ◽  
Near Field ◽  
Surface States ◽  
Field Energy ◽  
Hole Array ◽  
Infrared Range ◽  
Plasmonic Material ◽  
Edge Surface

Abstract Topological insulators are a new class of quantum materials with metallic (edge) surface states and insulating bulk states. They exhibit various novel electronic and optical properties that make them highly promising electronic, spintronic, and optoelectronic materials. Our report confirms that the topological insulator Bi 1.5 Sb 0.5 Te 1.8 Se 1.2 (BSTS) is also an effective plasmonic material in the visible and near-infrared range. A BSTS film can effectively control transmission and reflection characteristics by changing the period of the hole array. This study determined that a strong resonant surface plasmonic mode at the resonance peak can confine approximately 80% of the electromagnetic field energy is demonstrated. Higher-order (second- and third-order) resonance peaks were also found, which is critical for controlling electromagnetic waves and research into new optoelectronic devices.

scholarly journals Topological-Insulator-Based Gap-Surface Plasmon Metasurfaces

Photonics ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 40
Author(s):  
Andreas Aigner ◽  
Stefan A. Maier ◽  
Haoran Ren
Keyword(s):  
Surface Plasmon ◽  
Topological Insulator ◽  
Electromagnetic Waves ◽  
Beam Steering ◽  
Near Field ◽  
Surface States ◽  
Visible Spectrum ◽  
Visible Spectral Range ◽  
Far Field ◽  
Protected Surface

Topological insulators (TIs) have unique highly conducting symmetry-protected surface states while the bulk is insulating, making them attractive for various applications in condensed matter physics. Recently, topological insulator materials have been tentatively applied for both near- and far-field wavefront manipulation of electromagnetic waves, yielding superior plasmonic properties in the ultraviolet (UV)-to-visible wavelength range. However, previous reports have only demonstrated inefficient wavefront control based on binary metasurfaces that were digitalized on a TI thin film or non-directional surface plasmon polariton (SPP) excitation. Here, we numerically demonstrated the plasmonic capabilities of the TI Bi2Te3 as a material for gap–surface plasmon (GSP) metasurfaces. By employing the principle of the geometric phase, a far-field beam-steering metasurface was designed for the visible spectrum, yielding a cross-polarization efficiency of 34% at 500 nm while suppressing the co-polarization to 0.08%. Furthermore, a birefringent GSP metasurface design was studied and found to be capable of directionally exciting SPPs depending on the incident polarization. Our work forms the basis for accurately controlling the far- and near-field responses of TI-based GSP metasurfaces in the visible spectral range.

scholarly journals Near-field thermal radiation of deep- subwavelength slits in the near infrared range

2017 ◽  
Vol 25 (19) ◽  
pp. 23207
Author(s):  
Yan Guo ◽  
Kuanbiao Li ◽  
Ying Xu ◽  
Kaihua Wei
Keyword(s):  
Thermal Radiation ◽  
Near Infrared ◽  
Near Field ◽  
Infrared Range ◽  
Near Infrared Range

scholarly journals Methodological Basis of The UAVs Use for the Weed Detection

2018 ◽  
Keyword(s):  
Electromagnetic Waves ◽  
Near Infrared ◽  
Classification Method ◽  
Likelihood Method ◽  
Cultivated Plants ◽  
Visible Range ◽  
Infrared Range ◽  
Weed Detection ◽  
Weight Method ◽  
Remote Observation

Purpose. To work out methodological approaches to the use of quadcopters for weeds assesment. Methods. The shooting was carried out using DJI Phantom Vision 2+ and LadyBug Copper Dot. The LadyBug was shoted in the visible and near-infrared range using the 12-megapixel S100 NDVI UAV-Kit camera with elevations: 20 m, 40 m and 60 m. The DJI Phantom Vision 2+ was shot in the visible range of the GoPro 14 megapixel camera altitudes: 10 m, 15 m, 30 m and 60 m. Decryption of photographs was carried out using the controlled classification method in QGIS and TNTmips programs. Weed accounting was performed on control sites 1m2 by weight method, taking into account their qualitative composition. Results. It is shown that the best results of weed recognition during decoding of images was obtained by the use of controlled classification according to the maximum likelihood method under conditions of shooting from heights up to 40 m. In order to improve the recognition of weeds and separate their image from images of cultivated plants, it is expedient to use the object-oriented analysis. At the stage of sunflower budding, about 30% of the weeds are closed from the remote observation, which led to an automatic underestimation of number of weeds. Conclusions. In order to evaluate the crop contamination, it is possible to successfully use the data from UAVs in a visible range of electromagnetic waves under low altitudes (up to 40 meters) and the use of a controlled classification method for decoding images. For the recognition of weeds, the images in the infrared range do not have advantages over images in the visible range. It is necessary to additionally apply ground-based control of weeds to assess the proportion of "hidden" from remote observation of weeds.

Near-Field Tomography and Spectroscopy of Surface States on a Three-Dimensional Topological Insulator

2019 ◽  
Author(s):  
Fabian Sandner ◽  
Fabian Mooshammer ◽  
Markus A. Huber ◽  
Martin Zizlsperger ◽  
Helena Weigand ◽  
...  
Keyword(s):  
Topological Insulator ◽  
Near Field ◽  
Three Dimensional ◽  
Surface States

scholarly journals Intrinsically core-shell plasmonic dielectric nanostructures with ultrahigh refractive index

2016 ◽  
Vol 2 (3) ◽  
pp. e1501536 ◽  
Author(s):  
Zengji Yue ◽  
Boyuan Cai ◽  
Lan Wang ◽  
Xiaolin Wang ◽  
Min Gu
Keyword(s):  
Refractive Index ◽  
High Performance ◽  
Topological Insulators ◽  
Near Infrared ◽  
Surface States ◽  
Core Shell ◽  
Frequency Range ◽  
Plasmonic Nanostructure ◽  
Edge Surface ◽  
Infrared Frequency Range

Topological insulators are a new class of quantum materials with metallic (edge) surface states and insulating bulk states. They demonstrate a variety of novel electronic and optical properties, which make them highly promising electronic, spintronic, and optoelectronic materials. We report on a novel conic plasmonic nanostructure that is made of bulk-insulating topological insulators and has an intrinsic core-shell formation. The insulating (dielectric) core of the nanocone displays an ultrahigh refractive index of up to 5.5 in the near-infrared frequency range. On the metallic shell, plasmonic response and strong backward light scattering were observed in the visible frequency range. Through integrating the nanocone arrays into a-Si thin film solar cells, up to 15% enhancement of light absorption was predicted in the ultraviolet and visible ranges. With these unique features, the intrinsically core-shell plasmonic nanostructure paves a new way for designing low-loss and high-performance visible to infrared optical devices.

Infrared and Visible—Near Infrared Electroluminescence Developments for FA in AlGaN/GaN HEMTS on SiC

2010 ◽  
Author(s):  
M. Bouya ◽  
D. Carisetti ◽  
J.C. Clement ◽  
N. Malbert ◽  
N. Labat ◽  
...  
Keyword(s):  
Failure Analysis ◽  
Near Infrared ◽  
High Electron Mobility Transistor ◽  
Low Noise ◽  
Civil Defense ◽  
Base Stations ◽  
Infrared Range ◽  
High Electron ◽  
Radar Applications ◽  
Gan Hemts

Abstract HEMT (High Electron Mobility Transistor) are playing a key role for power and RF low noise applications. They are crucial components for the development of base stations in the telecommunications networks and for civil, defense and space radar applications. As well as the improvement of the MMIC performances, the localization of the defects and the failure analysis of these devices are very challenging. To face these challenges, we have developed a complete approach, without degrading the component, based on front side failure analysis by standard (Visible-NIR) and Infrared (range of wavelength: 3-5 µm) electroluminescence techniques. Its complementarities and efficiency have been demonstrated through two case studies.

scholarly journals Creation of Negatively Charged Boron Vacancies in Hexagonal Boron Nitride Crystal by Electron Irradiation and Mechanism of Inhomogeneous Broadening of Boron Vacancy-Related Spin Resonance Lines

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1373
Author(s):  
Fadis F. Murzakhanov ◽  
Boris V. Yavkin ◽  
Georgiy V. Mamin ◽  
Sergei B. Orlinskii ◽  
Ivan E. Mumdzhi ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Electron Irradiation ◽  
Near Infrared ◽  
Hexagonal Boron Nitride ◽  
Optical Excitation ◽  
High Energy ◽  
Infrared Range ◽  
Zero Field ◽  
Zero Field Splitting ◽  
Spin Resonance

Optically addressable high-spin states (S ≥ 1) of defects in semiconductors are the basis for the development of solid-state quantum technologies. Recently, one such defect has been found in hexagonal boron nitride (hBN) and identified as a negatively charged boron vacancy (VB−). To explore and utilize the properties of this defect, one needs to design a robust way for its creation in an hBN crystal. We investigate the possibility of creating VB− centers in an hBN single crystal by means of irradiation with a high-energy (E = 2 MeV) electron flux. Optical excitation of the irradiated sample induces fluorescence in the near-infrared range together with the electron spin resonance (ESR) spectrum of the triplet centers with a zero-field splitting value of D = 3.6 GHz, manifesting an optically induced population inversion of the ground state spin sublevels. These observations are the signatures of the VB− centers and demonstrate that electron irradiation can be reliably used to create these centers in hBN. Exploration of the VB− spin resonance line shape allowed us to establish the source of the line broadening, which occurs due to the slight deviation in orientation of the two-dimensional B-N atomic plains being exactly parallel relative to each other. The results of the analysis of the broadening mechanism can be used for the crystalline quality control of the 2D materials, using the VB− spin embedded in the hBN as a probe.

scholarly journals Single-shot imaging of surface molecular ionization in nanosystems

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Fenghao Sun ◽  
Hui Li ◽  
Shanshan Song ◽  
Fei Chen ◽  
Jiawei Wang ◽  
...  
Keyword(s):  
Near Infrared ◽  
Strong Field ◽  
Imaging Technique ◽  
Near Field ◽  
Velocity Map Imaging ◽  
Single Shot ◽  
Surface Molecules ◽  
Nanoparticle Interactions ◽  
Field Response ◽  
Ion Species

Abstract Using single-shot velocity map imaging technique, explosion imaging of different ion species ejected from 50 nm SiO2 nanoparticles are obtained excitedly by strong near-infrared and ultraviolet femtosecond laser fields. Characteristic momentum distributions showing forward emission of the ions at low excitation intensities and shock wave behaviors at high intensities are observed. When the excitation intensity is close to the dissociative ionization threshold of the surface molecules, the resulting ion products can be used to image the instant near-field distributions. The underlying dynamics of shock formation are simulated by using a Coulomb explosion model. Our results allow one to distinguish the ultrafast strong-field response of various molecular species in nanosystems and will open a new way for further exploration of the underlying dynamics of laser-and-nanoparticle interactions.

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