scholarly journals Extending the near-infrared band-edge absorption spectrum of silicon by proximity to a 2D semiconductor

2021 ◽  
Vol 538 ◽  
pp. 147803
Author(s):  
Valerio Apicella ◽  
Teslim Ayinde Fasasi ◽  
Hon Fai Wong ◽  
Dennis C.W. Leung ◽  
Antonio Ruotolo
Keyword(s):  
Absorption Spectrum ◽  
Near Infrared ◽  
Band Edge ◽  
Infrared Band ◽  
Edge Absorption

scholarly journals The Equivalent Thermal Conductivity of the Micro/Nano Scaled Periodic Cubic Frame Silver and Its Thermal Radiation Mechanism Analysis

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4158
Author(s):  
Haiyan Yu ◽  
Haochun Zhang ◽  
Heming Wang ◽  
Dong Zhang
Keyword(s):  
Thermal Conductivity ◽  
Thermal Radiation ◽  
Cell Size ◽  
Near Infrared ◽  
High Porosity ◽  
Mechanism Analysis ◽  
Infrared Band ◽  
Spectral Radiation ◽  
Radiation Mechanism ◽  
Equivalent Thermal Conductivity

Currently, there are few studies on the influence of microscale thermal radiation on the equivalent thermal conductivity of microscale porous metal. Therefore, this paper calculated the equivalent thermal conductivity of high-porosity periodic cubic silver frame structures with cell size from 100 nm to 100 µm by using the microscale radiation method. Then, the media radiation characteristics, absorptivity, reflectivity and transmissivity were discussed to explain the phenomenon of the radiative thermal conductivity changes. Furthermore, combined with spectral radiation properties at the different cross-sections and wavelength, the radiative transmission mechanism inside high-porosity periodic cubic frame silver structures was obtained. The results showed that the smaller the cell size, the greater radiative contribution in total equivalent thermal conductivity. Periodic cubic silver frames fluctuate more in the visible band and have better thermal radiation modulation properties in the near infrared band, which is formed by the Surface Plasmon Polariton and Magnetic Polaritons resonance jointly. This work provides design guidance for the application of this kind of periodic microporous metal in the field of thermal utilization and management.

An A–D–A′–D–A type small molecule acceptor with wide absorption spectrum and near-infrared absorption

2018 ◽  
Vol 2 (12) ◽  
pp. 2333-2339 ◽  
Author(s):  
Junhui Miao ◽  
Junxia Wang ◽  
Bin Meng ◽  
Jun Liu ◽  
Lixiang Wang
Keyword(s):  
Absorption Spectrum ◽  
Small Molecule ◽  
Infrared Absorption ◽  
Near Infrared

We report a new A–D–A′–D–A type small molecule acceptor with a wide absorption spectrum spanning from 300 nm to 900 nm and a bandgap of only 1.39 eV.

scholarly journals Restoration method of sootiness mural images based on dark channel prior and Retinex by bilateral filter

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Ning Cao ◽  
Shuqiang Lyu ◽  
Miaole Hou ◽  
Wanfu Wang ◽  
Zhenhua Gao ◽  
...  
Keyword(s):  
Near Infrared ◽  
Environmental Changes ◽  
Color Image ◽  
Visual Quality ◽  
Bilateral Filter ◽  
Dark Channel Prior ◽  
Infrared Band ◽  
Dark Channel ◽  
Restoration Method ◽  
Pseudo Color

AbstractEnvironmental changes and human activities can cause serious degradation of murals, where sootiness is one of the most common problems of ancient Chinese indoor murals. In order to improve the visual quality of the murals, a restoration method is proposed for sootiness murals based on dark channel prior and Retinex by bilateral filter using hyperspectral imaging technology. First, radiometric correction and denoising through band clipping and minimum noise fraction rotation forward and inverse transform were applied to the hyperspectral data of the sootiness mural to produce its denoised reflectance image. Second, a near-infrared band was selected from the reflectance image and combined with the green and blue visible bands to produce a pseudo color image for the subsequent sootiness removal processing. The near-infrared band is selected because it is better penetrating the sootiness layer to a certain extent comparing to other bands. Third, the sootiness covered on the pseudo color image was preliminarily removed by using the method of dark channel prior and by adjusting the brightness of the image. Finally, the Retinex by bilateral filter was performed on the image to get the final restored image, where the sootiness was removed. The results show that the images restored by the proposed method are superior in variance, average gradient, information entropy and gray scale contrast comparing to the results from the traditional methods of homomorphic filtering and Gaussian stretching. The results also show the highest score in comprehensive evaluation of edges, hue and structure; thus, the method proposed can support more potential studies or sootiness removal in real mural paintings with more detailed information. The method proposed shows strong evidence that it can effectively reduce the influence of sootiness on the moral images with more details that can reveal the original appearance of the mural and improve its visual quality.

Sensing Characteristics of Near-Infrared Band Based on New Photonic Crystal Fiber

2021 ◽  
Vol 48 (7) ◽  
pp. 0706001
Author(s):  
张文 Zhang Wen ◽  
白冰冰 Bai Bingbing ◽  
张砚曾 Zhang Yanzeng ◽  
陈聪 Chen Cong ◽  
邵齐元 Shao Qiyuan ◽  
...  
Keyword(s):  
Photonic Crystal ◽  
Photonic Crystal Fiber ◽  
Near Infrared ◽  
Infrared Band ◽  
Crystal Fiber ◽  
Sensing Characteristics

scholarly journals Bacteriorhodopsin induces a light-scattering change in Halobacterium halobium.

1978 ◽  
Vol 79 (3) ◽  
pp. 657-662 ◽  
Author(s):  
C L Wey ◽  
P L Ahl ◽  
R A Cone
Keyword(s):  
Absorption Spectrum ◽  
Light Scattering ◽  
Near Infrared ◽  
Action Spectrum ◽  
Bright Light ◽  
Infrared Region ◽  
Halobacterium Halobium ◽  
Scattering Response ◽  
Near Infrared Region ◽  
Hypertonic Shock

When suspensions of Halobacterium halobium are exposed to bright light, the light-scattering properties of the bacteria change. This light-scattering response can produce a transmission decrease of about 1% throughout the red and near-infrared region. The action spectrum for the light-scattering response appropriately matches the absorption spectrum of bacteriorhodopsin. The response is eliminated by cyanide p-trifluoro-methoxyphenylhydrazone, a proton ionophore, and by triphenylmethylphosphonium, a membrane permanent cation. A mild hypertonic shock induces a similar light-scattering change, suggesting that bright light causes the bacteria to shrink about 1% in volume, thereby producing the light-scattering response.

The Effects of Composition on the Spectral Loss Characteristics of SiGe Planar Waveguide Structures

1992 ◽  
Vol 281 ◽  
Author(s):  
Yang Zuoya ◽  
B. L. Weiss ◽  
G. Shao ◽  
F. Namavar
Keyword(s):  
Optical Properties ◽  
Planar Waveguide ◽  
Waveguide Structure ◽  
Propagation Loss ◽  
Band Edge ◽  
Optical Confinement ◽  
Structural And Optical Properties ◽  
Edge Absorption

ABSTRACTThe effect of the Si:Ge ratio in SiGe/Si heterostructures on the structural and optical properties of SiGe/Si planar waveguide are reported here for Ge concentrations from 1 to 33.6%. The high propagation loss at 1.15 pm is due to band edge absorption, which increases as the Ge concentration increases, while the loss at longer wavelengths (1.523 pm) increases with decreasing Si concentration, due to the reduced optical confinement of the waveguide structure.

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