scholarly journals A Plasmonic Infrared Multiple-Channel Filter Based on Gold Composite Nanocavities Metasurface

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1824
Author(s):  
Jialin Zhang ◽  
Xuanyi Yu ◽  
Jingxin Dong ◽  
Weiji Yang ◽  
Shuang Liu ◽  
...  
Keyword(s):  
Optical Transmission ◽  
Near Infrared ◽  
Single Layer ◽  
Geometrical Parameters ◽  
Biological Sensing ◽  
Photonic Switching ◽  
Multiple Channel ◽  
Sensing Systems ◽  
Periodic Composite ◽  
Channel Filter

A plasmonic near-infrared multiple-channel filter is numerically and experimentally investigated based on a gold periodic composite nanocavities metasurface. By the interference among different excited plasmonic modes on the metasurface, the multipeak extraordinary optical transmission (EOT) phenomenon is induced and utilized to realize multiple-channel filtering. Investigated from the simulated transmission spectrum of the metasurface, the positions and intensity of transmission peaks are tuned by the geometrical parameters of the metasurface and environmental refractive index. The fabricated metasurface approached transmission peaks at 1128 nm, 1245 nm, and 1362 nm, functioning as a three-passbands filter. With advantages of brief single-layer fabrication and multi-frequency selectivity, the proposed plasmonic filter has potential possibilities of integration in nano-photonic switching, detecting and biological sensing systems.

THE GRAPHENE-SiC SUBSTRATE INTERACTION ENHANCED NEAR-INFRARED ABSORPTION

2011 ◽  
Vol 25 (16) ◽  
pp. 1393-1399
Author(s):  
X. G. XU ◽  
R. YIN ◽  
G. J. XU ◽  
J. C. CAO
Keyword(s):  
Optical Absorption ◽  
Optical Transmission ◽  
Near Infrared ◽  
Visible Region ◽  
Single Layer ◽  
Finite Energy ◽  
Infrared Region ◽  
Single Layer Graphene ◽  
Substrate Effect ◽  
Theoretical Results

When epitaxially grown on silicon carbide, a single layer graphene will exhibit a finite energy bandgap like a conventional semiconductor, and its energy dispersion is no longer linear in momentum space in the low energy regime. In this paper, we present a quantitative analysis on the effect of the SiC substrate in the optical absorption of π-electrons in graphene. We calculated the absorption matrix element and the optical absorption in the near infrared even to the visible region by taking into account the SiC substrate effect. It has been found that the substrate effect can significantly enhance the optical absorption in graphene in the near-infrared region, even by up to 90%. It may be helpful to eliminate the previous discrepancy of optical transmission between the theoretical results and the experimental results in the near-infrared to the visible region.

Effects of Varying Geometrical Parameters on Boiling From Microfabricated Enhanced Structures

2003 ◽  
Vol 125 (1) ◽  
pp. 103-109 ◽  
Author(s):  
C. Ramaswamy ◽  
Y. Joshi ◽  
W. Nakayama ◽  
W. B. Johnson
Keyword(s):  
Heat Dissipation ◽  
Layer Structure ◽  
Single Layer ◽  
Nucleate Boiling ◽  
Heat Fluxes ◽  
Working Fluid ◽  
Geometrical Parameters ◽  
Small Range ◽  
Two Phase ◽  
Wall Superheat

The current study involves two-phase cooling from enhanced structures whose dimensions have been changed systematically using microfabrication techniques. The aim is to optimize the dimensions to maximize the heat transfer. The enhanced structure used in this study consists of a stacked network of interconnecting channels making it highly porous. The effect of varying the pore size, pitch and height on the boiling performance was studied, with fluorocarbon FC-72 as the working fluid. While most of the previous studies on the mechanism of enhanced nucleate boiling have focused on a small range of wall superheats (0–4 K), the present study covers a wider range (as high as 30 K). A larger pore and smaller pitch resulted in higher heat dissipation at all heat fluxes. The effect of stacking multiple layers showed a proportional increase in heat dissipation (with additional layers) in a certain range of wall superheat values only. In the wall superheat range 8–13 K, no appreciable difference was observed between a single layer structure and a three layer structure. A fin effect combined with change in the boiling phenomenon within the sub-surface layers is proposed to explain this effect.

scholarly journals Nanoprinted high-neuron-density optical linear perceptrons performing near-infrared inference on a CMOS chip

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Elena Goi ◽  
Xi Chen ◽  
Qiming Zhang ◽  
Benjamin P. Cumming ◽  
Steffen Schoenhardt ◽  
...  
Keyword(s):  
Machine Learning ◽  
High Speed ◽  
Near Infrared ◽  
Single Layer ◽  
Infrared Region ◽  
Optical Devices ◽  
Medical Diagnostics ◽  
Oxide Semiconductor ◽  
Process Data ◽  
Neuron Density

AbstractOptical machine learning has emerged as an important research area that, by leveraging the advantages inherent to optical signals, such as parallelism and high speed, paves the way for a future where optical hardware can process data at the speed of light. In this work, we present such optical devices for data processing in the form of single-layer nanoscale holographic perceptrons trained to perform optical inference tasks. We experimentally show the functionality of these passive optical devices in the example of decryptors trained to perform optical inference of single or whole classes of keys through symmetric and asymmetric decryption. The decryptors, designed for operation in the near-infrared region, are nanoprinted on complementary metal-oxide–semiconductor chips by galvo-dithered two-photon nanolithography with axial nanostepping of 10 nm1,2, achieving a neuron density of >500 million neurons per square centimetre. This power-efficient commixture of machine learning and on-chip integration may have a transformative impact on optical decryption3, sensing4, medical diagnostics5 and computing6,7.

High-Throughput Synthesis of Single-Layer MoS2 Nanosheets as a Near-Infrared Photothermal-Triggered Drug Delivery for Effective Cancer Therapy

ACS Nano ◽  
2014 ◽  
Vol 8 (7) ◽  
pp. 6922-6933 ◽  
Author(s):  
Wenyan Yin ◽  
Liang Yan ◽  
Jie Yu ◽  
Gan Tian ◽  
Liangjun Zhou ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Cancer Therapy ◽  
High Throughput ◽  
Near Infrared ◽  
Single Layer ◽  
Mos2 Nanosheets ◽  
Effective Cancer Therapy

scholarly journals Aluminum Doping Effect on Surface Structure of Silver Ultrathin Films

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 648
Author(s):  
Han Yan ◽  
Xiong Xu ◽  
Peng Li ◽  
Peijie He ◽  
Qing Peng ◽  
...  
Keyword(s):  
Density Functional ◽  
Near Infrared ◽  
Single Layer ◽  
Density Functional Theory Calculations ◽  
Light Transmittance ◽  
Formation Mechanisms ◽  
Silver Surface ◽  
Silver Films ◽  
Migration Pathway ◽  
Surface Morphologies

Ultrathin silver films with low loss in the visible and near-infrared spectrum range have been widely used in the fields of metamaterials and optoelectronics. In this study, Al-doped silver films were prepared by the magnetron sputtering method and were characterized by surface morphology, electrical conductivity, and light transmittance analyses. Molecular dynamics simulations and first-principles density functional theory calculations were applied to study the surface morphologies and migration pathway for the formation mechanisms in Al-doped silver films. The results indicate that the migration barrier of silver on a pristine silver surface is commonly lower than that of an Al-doped surface, revealing that the aluminum atoms in the doping site decrease the surface mobility and are conducive to the formation of small islands of silver. When the islands are dense, they coalesce into a single layer, leading to a smoother surface. This might be the reason for the observably lower 3D growth mode of silver on an Al-doped silver surface. Our results with electronic structure insights on the mechanism of the Al dopants on surface morphologies might benefit the quality control of the silver thin films.

scholarly journals Polarimetry and Physics of Be Star Envelopes (Review paper)

1982 ◽  
Vol 98 ◽  
pp. 77-93 ◽  
Author(s):  
George V. Coyne ◽  
Ian S. McLean
Keyword(s):  
High Resolution ◽  
Near Infrared ◽  
Theoretical Models ◽  
Geometrical Parameters ◽  
Be Stars ◽  
Intermediate Band ◽  
Wide Range ◽  
Recent Developments ◽  
Be Star ◽  
Polarization Studies

A review of the most recent developments in polarization studies of Be stars is presented. New polarization techniques for high-resolution spectropolarimetry and for near infrared polarimetry are described and a wide range of new observations are discussed. These include broadband, intermediate-band and multichannel observations of the continuum polarization of Be stars in the wavelenght interval 0.3–2.2 microns, high resolution (0.5 Å) line profile polarimetry of a few stars and surveys of many stars for the purposes of statistical analyses. The physical significance of the observational material is discussed in the light of recent theoretical models. Emphasis is placed on the physical and geometrical parameters of Be star envelopes which polarimetry helps to determine.

scholarly journals Monolayer MoS2 for nanoscale photonics

Nanophotonics ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 1557-1577 ◽  
Author(s):  
Xianguang Yang ◽  
Baojun Li
Keyword(s):  
Near Infrared ◽  
Transition Metal Dichalcogenides ◽  
Single Layer ◽  
Band Gaps ◽  
Laser Source ◽  
Two Dimensional ◽  
Strong Light ◽  
Metal Dichalcogenides ◽  
Optoelectronic Applications ◽  
Flexible Photodetector

AbstractTransition metal dichalcogenides are two-dimensional semiconductors with strong in-plane covalent and weak out-of-plane interactions, resulting in exfoliation into monolayers with atomically thin thickness. This creates a new era for the exploration of two-dimensional physics and device applications. Among them, MoS2 is stable in air and easily available from molybdenite, showing tunable band-gaps in the visible and near-infrared waveband and strong light-matter interactions due to the planar exciton confinement effect. In the single-layer limit, monolayer MoS2 exhibits direct band-gaps and bound excitons, which are fundamentally intriguing for achieving the nanophotonic and optoelectronic applications. In this review, we start from the characterization of monolayer MoS2 in our group and understand the exciton modes, then explore thermal excitons and band renormalization in monolayer MoS2. For nanophotonic applications, the recent progress of nanoscale laser source, exciton-plasmon coupling, photoluminescence manipulation, and the MoS2 integration with nanowires or metasurfaces are overviewed. Because of the benefits brought by the unique electronic and mechanical properties, we also introduce the state of the art of the optoelectronic applications, including photoelectric memory, excitonic transistor, flexible photodetector, and solar cell. The critical applications focused on in this review indicate that MoS2 is a promising material for nanophotonics and optoelectronics.

scholarly journals Multilayer Cloud Detection with the MODIS Near-Infrared Water Vapor Absorption Band

2010 ◽  
Vol 49 (11) ◽  
pp. 2315-2333 ◽  
Author(s):  
Galina Wind ◽  
Steven Platnick ◽  
Michael D. King ◽  
Paul A. Hubanks ◽  
Michael J. Pavolonis ◽  
...  
Keyword(s):  
Water Vapor ◽  
Near Infrared ◽  
Single Layer ◽  
Precipitable Water ◽  
Detection Algorithm ◽  
Cloud Detection ◽  
Water Vapor Absorption ◽  
Cloud Properties ◽  
Cloud Models ◽  
Moderate Resolution Imaging Spectroradiometer

Abstract Data Collection 5 processing for the Moderate Resolution Imaging Spectroradiometer (MODIS) on board the NASA Earth Observing System (EOS) Terra and Aqua spacecraft includes an algorithm for detecting multilayered clouds in daytime. The main objective of this algorithm is to detect multilayered cloud scenes, specifically optically thin ice cloud overlying a lower-level water cloud, that present difficulties for retrieving cloud effective radius using single-layer plane-parallel cloud models. The algorithm uses the MODIS 0.94-μm water vapor band along with CO2 bands to obtain two above-cloud precipitable water retrievals, the difference of which, in conjunction with additional tests, provides a map of where multilayered clouds might potentially exist. The presence of a multilayered cloud results in a large difference in retrievals of above-cloud properties between the CO2 and the 0.94-μm methods. In this paper the MODIS multilayered cloud algorithm is described, results of using the algorithm over example scenes are shown, and global statistics for multilayered clouds as observed by MODIS are discussed. A theoretical study of the algorithm behavior for simulated multilayered clouds is also given. Results are compared to two other comparable passive imager methods. A set of standard cloudy atmospheric profiles developed during the course of this investigation is also presented. The results lead to the conclusion that the MODIS multilayer cloud detection algorithm has some skill in identifying multilayered clouds with different thermodynamic phases.

scholarly journals Ultrabroadband Absorption Enhancement via Hybridization of Localized and Propagating Surface Plasmons

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1625
Author(s):  
Tian Sang ◽  
Honglong Qi ◽  
Xun Wang ◽  
Xin Yin ◽  
Guoqing Li ◽  
...  
Keyword(s):  
Surface Plasmon ◽  
Near Infrared ◽  
Low Cost ◽  
Polarized Light ◽  
Wavelength Region ◽  
Transverse Magnetic ◽  
Localized Surface Plasmon ◽  
Absorption Enhancement ◽  
Geometrical Parameters ◽  
Light Illumination

Broadband metamaterial absorbers (MAs) are critical for applications of photonic and optoelectronic devices. Despite long-standing efforts on broadband MAs, it has been challenging to achieve ultrabroadband absorption with high absorptivity and omnidirectional characteristics within a comparatively simple and low-cost architecture. Here we design, fabricate, and characterize a novel compact Cr-based MA to achieve ultrabroadband absorption in the visible to near-infrared wavelength region. The Cr-based MA consists of Cr nanorods and Cr substrate sandwiched by three pairs of SiO2/Cr stacks. Both simulated and experimental results show that an average absorption over 93.7% can be achieved in the range of 400–1000 nm. Specifically, the ultrabroadband features result from the co-excitations of localized surface plasmon (LSP) and propagating surface plasmon (PSP) and their synergistic absorption effects, where absorption in the shorter and longer wavelengths are mainly contributed bythe LSP and PSP modes, respectively. The Cr-based MA is very robust to variations of the geometrical parameters, and angle-and polarization-insensitive absorption can be operated well over a large range of anglesunder both transverse magnetic(TM)- and transverse electric (TE)-polarized light illumination.

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