scholarly journals A novel dual-path high-throughput acousto-optic tunable filter imaging spectropolarimeter

2020 ◽  
Author(s):  
Ramy Abdlaty ◽  
Qiyin Fang
Keyword(s):  
Spectral Resolution ◽  
Near Infrared ◽  
Beam Splitter ◽  
Tunable Filter ◽  
Infrared Range ◽  
Human Tissues ◽  
Heterogeneous Environment ◽  
Tissue Samples ◽  
Preference Information ◽  
Near Infrared Range

It is highly demanding to identify healthy and non-healthy species in a heterogeneous environment such as human tissues. In such a case, one identifier, such as a spectral fingerprint, might be inadequate. Therefore, additional identification is required, for instance, a polarisation measurement. In view of that, the development of a spectropolarimeter that captures two cross-polarised arrays of spectral images is a key requirement. To meet this requirement, an imager optical setup has been designed to provide spatial, spectral and polarisation preference information for species that exist in a heterogeneous environment, such as in medical tissue samples. The spectral and polarisation information is obtained employing an acousto-optic tunable filter and a polarising beam splitter, respectively. The optical imager is designed to operate in the visible-near infrared range (450–850 nm) with a spectral resolution of 3 nm. The spectropolarimeter design along with optical characterisation results are reported.

Coupling of Er light emissions to plasmon modes on In2O3: Sn nanoparticle sheets in the near-infrared range

2014 ◽  
Vol 105 (4) ◽  
pp. 041903 ◽  
Author(s):  
Hiroaki Matsui ◽  
Wasanthamala Badalawa ◽  
Takayuki Hasebe ◽  
Shinya Furuta ◽  
Wataru Nomura ◽  
...  
Keyword(s):  
Near Infrared ◽  
Infrared Range ◽  
Near Infrared Range ◽  
Sn Nanoparticle ◽  
Plasmon Modes

scholarly journals Fabrication of Dy2O3 Transparent Ceramics by Vacuum Sintering Using Precipitated Powders

2020 ◽  
Vol 7 (1) ◽  
pp. 6
Author(s):  
Dianjun Hu ◽  
Xin Liu ◽  
Ziyu Liu ◽  
Xiaoying Li ◽  
Feng Tian ◽  
...  
Keyword(s):  
Near Infrared ◽  
Optical Quality ◽  
Precipitation Method ◽  
Infrared Range ◽  
Transparent Ceramics ◽  
Vacuum Sintering ◽  
Hydrogen Carbonate ◽  
Ammonium Hydrogen ◽  
Liquid Precipitation ◽  
Near Infrared Range

As a kind of promising material for a Faraday isolator used in the visible and near infrared range, Dy2O3 transparent ceramics were prepared by vacuum sintering from the nano-powders synthesized by the liquid precipitation method using ammonium hydrogen carbonate as precipitant with no sintering aids. The synthesized precursor was calcinated at 950 °C–1150 °C for 4 h in air. The influences of the calcination temperature on the morphologies and phase composition of Dy2O3 powders were characterized. It is found that the Dy2O3 powder calcinated at 1000 °C for 4 h is superior for the fabrication of Dy2O3 ceramics. The Dy2O3 transparent ceramic sample prepared by vacuum sintering at 1850 °C for 10 h, and subsequently with air annealing at 1400 °C for 10 h, from the 1000 °C-calcined Dy2O3 powders, presents the best optical quality. The values of in-line transmittance of the optimal ceramic specimen with the thickness of 1.0 mm are 75.3% at 2000 nm and 67.9% at 633 nm. The Verdet constant of Dy2O3 ceramics was measured to be −325.3 ± 1.9 rad/(T·m) at 633 nm, about 2.4 times larger than that of TGG (Tb3Ga5O12) single crystals.

scholarly journals Joint Measurements of PM<sub>2.5</sub> and light-absorptive PM in woodsmoke-dominated ambient and plume environments

2017 ◽  
Author(s):  
K. Max Zhang ◽  
Bo Yang ◽  
Geng Chen ◽  
Jiajun Gu ◽  
James Schwab ◽  
...  
Keyword(s):  
Near Infrared ◽  
Uv Light ◽  
Operating Conditions ◽  
Infrared Range ◽  
Wood Combustion ◽  
Near Ultraviolet ◽  
Linear Relationships ◽  
Saranac Lake ◽  
Near Infrared Range ◽  
Strong Linear Relationship

Abstract. DC, also referred to as Delta-C, measures enhanced light absorption of particulate matter (PM) samples at the near-ultraviolet (UV) range relative to the near-infrared range, which has been proposed previously as a woodsmoke marker due to the presence of enhanced UV light absorbing materials from wood combustion. In this paper, we further evaluated the applications and limitations of using DC as both a qualitative and semi-quantitative woodsmoke marker via joint continuous measurements of PM2.5 (by nephelometer pDR-1500) and light-absorptive PM (by 2-wavelength and 7-wavelength Aethalometer®) in three Northeastern U.S. cities/towns including Rutland, VT, Saranac Lake, NY and Ithaca, NY. We compared the pDR-1500 against a FEM PM2.5 sampler (BAM 1020), and identified a close agreement between the two instruments in a woodsmoke-dominated ambient environment. The analysis of seasonal and diurnal trends of DC, BC (880 nm) and PM2.5 concentrations supports the use of DC as an adequate qualitative marker. The strong linear relationships between PM2.5 and DC in both woodsmoke-dominated ambient and plume environments suggest that DC can reasonably serve as a semi-quantitative woodsmoke marker. We proposed a DC-based indicator for woodsmoke emission, which was then shown to exhibit relatively strong linear relationship with heating demand. While we observed reproducible PM2.5-DC relationships in similar woodsmoke-dominated ambient environments, those relationships differ significantly with different environments, and among individual woodsmoke sources. DC correlated much more closely with PM2.5 than EcoChem PAS2000-reported PAH in woodsmoke-dominated ambient environments. Our analysis also indicates the potential for PM2.5-DC relationships to be utilized to distinguish different combustion and operating conditions of woodsmoke sources, and that DC-Heating demand relationships could be adopted to estimate woodsmoke emissions. However, future studies are needed to elucidate those relationships.

scholarly journals Interaction in quasibinary systems based on TlSbP2Se6 and compounds of the Tl2Se-Sb2Se3 system

2019 ◽  
Vol 85 (3) ◽  
pp. 20-26
Author(s):  
Viktoria Sabov ◽  
Мaria Potorij ◽  
Iwan Kityk ◽  
Mykhailo Filep ◽  
Marian Sabov
Keyword(s):  
Cross Sections ◽  
Near Infrared ◽  
Practical Interest ◽  
Infrared Range ◽  
Thermally Stable ◽  
Quaternary Compound ◽  
Metal Compounds ◽  
Temperature Method ◽  
The Family ◽  
Near Infrared Range

Complex chalcogenides display semiconductor properties. In particular, heavy metal compounds that are formed in the Tl2Se-Sb2Se3 system are good thermoelectric materials. At the same time TlSbP2Se6 compound belongs to the family of hexaseleno-hypodiphosphates, which representatives have a number of interesting properties (optoelectric, non-linear, etc.) in the near infrared range. The combination of these properties in one material causes some scientific and practical interest, therefore our research was aimed to study the nature of the interaction between TlSbP2Se6 and the thermally stable phases of the Tl2Se-Sb2Se3 system in order to find new promising candidate for applications in electronic devices. The alloys were prepared from corresponding binary, ternary compounds and quaternary TlSbP2Se6 by a direct one-temperature method in evacuated quartz ampoules at temperatures above the melting point of the initial and final products. The initial compounds were synthesized by the reaction of their high purity component elements in stoichiometric proportion. According to the results of the research, it was found that cross-sections based on TlSbP2Se6 and the thermally stable compounds of the Tl2Se-Sb2Se3 section are quasibinary: Sb2Se3–TlSbP2Se6 and TlSbSe2–TlSbP2Se6. Tl9SbSe6 – TlSbP2Se6 and Tl2Se - TlSbP2Se6 systems are not quasibinary, instead quasibinary sections Tl2Se-Tl4P2Se6 and Tl9SbSe6-Tl4P2Se6 which crossing their. The phase equilibrium in Sb2Se3 – TlSbP2Se6 and TlSbSe2 – TlSbP2Se6 systems were studied by common differential thermal analysis (DTA), X-ray powder diffraction (XRD) and microstructure analysis. The eutectic interactions are observed in both systems. The invariant points coordinates are: 77 mol.% TlSbP2Se6, 709 K (system Sb2Se3 – TlSbP2Se6) and 45 mol.% TISbSe2, 680 K (system TlSbSe2 – TlSbP2Se6). Significant boundary solid solutions are formed on the basis of the quaternary compound. Their region extends up to 10 mol% in the system Sb2Se3 – TlSbP2Se6 and to about 18 mol.% in the system TlSbSe2 –TlSbP2Se6 at annealing temperature (573 К). Near the Sb2Se3 and TlSbSe2, the solubility limits do not exceed several mol.%.

3D Plant Modelling Using Spectral Data from Visible to Near Infrared Range

2015 ◽  
pp. 273-294
Author(s):  
Ali Zia ◽  
Jie Liang
Keyword(s):  
Hyperspectral Imaging ◽  
Material Properties ◽  
Near Infrared ◽  
Infrared Range ◽  
Plant Surface ◽  
Imaging Device ◽  
Plant Phenomics ◽  
Physical Traits ◽  
Plant Modelling ◽  
Near Infrared Range

Plant phenomics research requires different types of sensors employed to measure the physical traits of plant surface and to estimate the biomass. Of particular interests is the hyperspectral imaging device which captures wavelength indexed band images that characterize material properties of objects under study. This chapter introduces a proof of concept research that builds 3D plant model directly from hyperspectral images captured in a controlled lab environment. The method presented in this chapter allows fine structural-spectral information of an object be captured and integrated into the 3D model, which can be used to support further research and applications. The hyperspectral imaging has shown clear advantages in segmenting plant from its background and is very promising in generating comprehensive 3D plant models.

Epitaxial synthesis of ultrathin β-In2Se3/MoS2 heterostructures with high visible/near-infrared photoresponse

Nanoscale ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 6480-6488 ◽  
Author(s):  
Zixing Zou ◽  
Dong Li ◽  
Junwu Liang ◽  
Xuehong Zhang ◽  
Huawei Liu ◽  
...  
Keyword(s):  
Near Infrared ◽  
Infrared Range ◽  
Near Infrared Range

Novel β-In2Se3/MoS2 vertically stacked heterostructures were synthesized, and can be further utilized as excellent photodetectors in the visible and near-infrared range.

scholarly journals In situ continuous visible and near-infrared spectroscopy of an alpine snowpack

2017 ◽  
Vol 11 (3) ◽  
pp. 1091-1110 ◽  
Author(s):  
Marie Dumont ◽  
Laurent Arnaud ◽  
Ghislain Picard ◽  
Quentin Libois ◽  
Yves Lejeune ◽  
...  
Keyword(s):  
Liquid Water ◽  
Near Infrared ◽  
Winter Season ◽  
Impurity Content ◽  
Saharan Dust ◽  
Infrared Range ◽  
Snow Surface ◽  
Surface Slope ◽  
Near Infrared Range

Abstract. Snow spectral albedo in the visible/near-infrared range has been continuously measured during a winter season at Col de Porte alpine site (French Alps; 45.30° N, 5.77° E; 1325 m a.s.l.). The evolution of such alpine snowpack is complex due to intensive precipitation, rapid melt events and Saharan dust deposition outbreaks. This study highlights that the resulting intricate variations of spectral albedo can be successfully explained by variations of the following snow surface variables: specific surface area (SSA) of snow, effective light-absorbing impurities content, presence of liquid water and slope. The methodology developed in this study disentangles the effect of these variables on snow spectral albedo. The presence of liquid water at the snow surface results in a spectral shift of the albedo from which melt events can be identified with an occurrence of false detection rate lower than 3.5 %. Snow SSA mostly impacts spectral albedo in the near-infrared range. Impurity deposition mostly impacts the albedo in the visible range but this impact is very dependent on snow SSA and surface slope. Our work thus demonstrates that the SSA estimation from spectral albedo is affected by large uncertainties for a tilted snow surface and medium to high impurity contents and that the estimation of impurity content is also affected by large uncertainties, especially for low values below 50 ng g−1 black carbon equivalent. The proposed methodology opens routes for retrieval of SSA, impurity content, melt events and surface slope from spectral albedo. However, an exhaustive accuracy assessment of the snow black properties retrieval would require more independent in situ measurements and is beyond the scope of the present study. This time series of snow spectral albedo nevertheless already provides a new insight into our understanding of the evolution of snow surface properties.

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