Shape-dependent absorption characteristics of three-layered metamaterial absorbers at near-infrared

2011 ◽  
Vol 109 (7) ◽  
pp. 074510 ◽  
Author(s):  
Jing Wang ◽  
Yiting Chen ◽  
Jiaming Hao ◽  
Min Yan ◽  
Min Qiu
2016 ◽  
Vol 136 (5) ◽  
pp. 172-179
Author(s):  
Yuta Ishii ◽  
Yuma Takida ◽  
Yoshiaki Kanamori ◽  
Hiroaki Minamide ◽  
Kazuhiro Hane

2016 ◽  
Vol 78 (3-2) ◽  
Author(s):  
Y.A. Tanko ◽  
M.R. Sahar ◽  
S.K. Ghoshal

Enhanced absorption and emission cross-sections of rare earth doped binary glasses are highly demanding for various photonic applications. Determining the right glass compositions with appropriate rare earth dopants remain challenging. Different microscopic mechanisms responsible for optical enhancement and quenching are not fully understood. In this view, we prepare a series of glasses with composition (80-x)TeO2-20ZnO-(x)Sm2O3, where 0 ≤ x ≤ 1.5 mol% using melt quenching technique. X-ray diffraction (XRD), Photoluminescence (PL) and Ultraviolet Visible Near-Infrared (UV-Vis-NIR) spectroscopic measurements are carried out to inspect the samarium concentration dependent absorption and emission features of the prepared glasses. Physical properties such as glass density and molar volume are found to be in the range 5.57-5.61 g cm-3 and 25.84-26.15 cm3 mol-1, respectively. XRD pattern verifies the amorphous nature of the prepared samples. The UV-Vis-NIR absorption spectra reveal nine peaks centered at 470, 548, 947, 1085, 1238, 1385, 1492, 1550 and 1589 nm. These bands arise due to 6H5/2→4I11/2, 4G5/2, 6F11/2, 6F9/2, 6F7/2, 6F5/2, 6F3/2, 6H15/2, and 6F1/2 transitions, respectively. PL spectra under the excitation of 452 nm display four emission bands centered at 563, 600, 644 and 705 nm corresponding to 4G5/2→6H5/2, 6H7/2, 6H9/2 and 6H11/2 transitions of samarium ions. The mechanism of photoluminescence enhancement is identified, analyzed, and understood. A correlation between samarium concentration and optical response is established. This composition may be useful for fabricating various optical devices


2019 ◽  
Vol 58 (26) ◽  
pp. 7134 ◽  
Author(s):  
Yanhong Zhu ◽  
Tian Lan ◽  
Pinwei Liu ◽  
Jiaqi Yang

1995 ◽  
Vol 413 ◽  
Author(s):  
Charles W. Spangler ◽  
Mingqian He

ABSTRACTElectroactive polymers such as poly [p-phenylene vinylene] (PPV) and poly [2,5-thienylene vinylene] (PTV) have been shown to yield highly conductive materials upon oxidative doping,1 and to display enhanced third order nonlinear optical response.2 Optical absorption spectra for either neutral or doped polymers, however, are quite broad, extending well into the visible for the neutral polymer and into the near infrared (NIR) for the doped polymers, with little evident fine structure. For certain nonlinear optical (NLO) applications, this can lead to undesirable absorption losses and resonance phenomena. We would like to describe how copolymers incorporating oligomeric dithienylpolyene segments may be designed so as to give some degree of control over the polymer absorption characteristics in either neutral or oxidized form.


Author(s):  
Yasuomi Endo ◽  
Yukari Tanikawa ◽  
Shinpei Okawa ◽  
Kazuto Masamoto ◽  
Hidetaka Okada ◽  
...  

Light in the near-infrared wavelength range can penetrate deeping into biological tissues because the absorption by both water and hemoglobin is much smaller than in the other wavelength ranges. Oxygenated and deoxygenated hemoglobins have different light absorption characteristics. Therefore, by obtaining tomographic images of the absorption characteristics, it will be possible to know the hemodynamics inside deep tissues. Thus, the diffuse optical tomography (DOT) is expected as a new modality of biomedical imaging. In this study, we try to obtain DOT images of the forearms by conducting two types of exercise, and their differences caused by the muscle activity are discussed. By comparing the reconstructed DOT images with the magnetic resonance images of the forearm at the same position, the activated muscles can be identified in detail. As a result, the hemodynamics in the dominant muscles when performing flexion and extension of wrist are observed.


2015 ◽  
Vol 2015 (0) ◽  
pp. _H214-1_-_H214-2_
Author(s):  
Hiroki Yamashita ◽  
Naoto Kakuta ◽  
Daisuke Kawashima ◽  
Katsuya Kondo ◽  
Hidenobu Arimoto ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document