Upconversion luminescence and optical behavior of Er3+ -doped Gd2O3 phosphors

2022 ◽  
pp. 169-180
Author(s):  
Kanchan Upadhyay ◽  
Raunak Kumar Tamrakar ◽  
Sabu Thomas
Author(s):  
A. Strojnik ◽  
J.W. Scholl ◽  
V. Bevc

The electron accelerator, as inserted between the electron source (injector) and the imaging column of the HVEM, is usually a strong lens and should be optimized in order to ensure high brightness over a wide range of accelerating voltages and illuminating conditions. This is especially true in the case of the STEM where the brightness directly determines the highest resolution attainable. In the past, the optical behavior of accelerators was usually determined for a particular configuration. During the development of the accelerator for the Arizona 1 MEV STEM, systematic investigation was made of the major optical properties for a variety of electrode configurations, number of stages N, accelerating voltages, 1 and 10 MEV, and a range of injection voltages ϕ0 = 1, 3, 10, 30, 100, 300 kV).


2020 ◽  
Vol 41 (11) ◽  
pp. 1351-1357
Author(s):  
Mei-juan YUANG ◽  
◽  
Jing LI ◽  
Hui-lian QIN ◽  
Ya-ru PENG ◽  
...  

2019 ◽  
Vol 96 ◽  
pp. 109286
Author(s):  
Abhishek Kumar ◽  
Luís Pinto da Silva ◽  
Joaquim C.G. Esteves da Silva ◽  
Kaushal Kumar

2020 ◽  
Vol 183 ◽  
pp. 108739
Author(s):  
Shivani ◽  
Ishpreet Kaur ◽  
Karthika Chemmanghattu ◽  
Paramjit Kaur ◽  
Kamaljit Singh

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1022
Author(s):  
Rashid G. Bikbaev ◽  
Ivan V. Timofeev ◽  
Vasiliy F. Shabanov

Optical sensing is one of many promising applications for all-dielectric photonic materials. Herein, we present an analytical and numerical study on the strain-responsive spectral properties of a bioinspired sensor. The sensor structure contains a two-dimensional periodic array of dielectric nanodisks to mimic the optical behavior of grana lamellae inside chloroplasts. To accumulate a noticeable response, we exploit the collective optical mode in grana ensemble. In higher plants, such a mode appears as Wood’s anomaly near the chlorophyll absorption line to control the photosynthesis rate. The resonance is shown persistent against moderate biological disorder and deformation. Under the stretching or compression of a symmetric structure, the mode splits into a couple of polarized modes. The frequency difference is accurately detected. It depends on the stretch coefficient almost linearly providing easy calibration of the strain-sensing device. The sensitivity of the considered structure remains at 5 nm/% in a wide range of strain. The influence of the stretching coefficient on the length of the reciprocal lattice vectors, as well as on the angle between them, is taken into account. This adaptive phenomenon is suggested for sensing applications in biomimetic optical nanomaterials.


2021 ◽  
Vol 45 (14) ◽  
pp. 6469-6478
Author(s):  
Qingling Zeng ◽  
Wenxiang He ◽  
Fangfei Luan ◽  
Yu Yan ◽  
Hongli Du ◽  
...  

SrF2:Yb3+,Er3+ NPs were synthesized by the hydrothermal method and their luminescence mechanism was discussed in detail, which provided a theoretical basis for further understanding the properties of the materials.


Nanophotonics ◽  
2020 ◽  
Vol 9 (14) ◽  
pp. 4233-4252
Author(s):  
Yael Gutiérrez ◽  
Pablo García-Fernández ◽  
Javier Junquera ◽  
April S. Brown ◽  
Fernando Moreno ◽  
...  

AbstractReconfigurable plasmonics is driving an extensive quest for active materials that can support a controllable modulation of their optical properties for dynamically tunable plasmonic structures. Here, polymorphic gallium (Ga) is demonstrated to be a very promising candidate for adaptive plasmonics and reconfigurable photonics applications. The Ga sp-metal is widely known as a liquid metal at room temperature. In addition to the many other compelling attributes of nanostructured Ga, including minimal oxidation and biocompatibility, its six phases have varying degrees of metallic character, providing a wide gamut of electrical conductivity and optical behavior tunability. Here, the dielectric function of the several Ga phases is introduced and correlated with their respective electronic structures. The key conditions for optimal optical modulation and switching for each Ga phase are evaluated. Additionally, we provide a comparison of Ga with other more common phase-change materials, showing better performance of Ga at optical frequencies. Furthermore, we first report, to the best of our knowledge, the optical properties of liquid Ga in the terahertz (THz) range showing its broad plasmonic tunability from ultraviolet to visible-infrared and down to the THz regime. Finally, we provide both computational and experimental evidence of extension of Ga polymorphism to bidimensional two-dimensional (2D) gallenene, paving the way to new bidimensional reconfigurable plasmonic platforms.


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