Effect of GeO2 additive on fluorescence intensity enhancement in bismuth-doped silica glass

2007 ◽  
Vol 22 (3) ◽  
pp. 565-568 ◽  
Author(s):  
Yasushi Fujimoto ◽  
Yuki Hirata ◽  
Yoshiyuki Kuwada ◽  
Takahiro Sato ◽  
Masahiro Nakatsuka

We observed the enhancement of fluorescence intensity due to the addition of GeO2 in bismuth-doped silica glass (BiSG), which has a peculiar fluorescence at 1.25 μm with a full width at half-maximum of 300 nm. Experimental results revealed that the fluorescence intensity from BiSG with 5.0 mol% GeO2 increased remarkably to be 26.3 times greater than that without GeO2 additive for the same Bi2O3 concentration (0.1 mol%). Furthermore, the enhanced sample showed almost the same intensity as BiSG without GeO2 for 1.0 mol% Bi2O3. These results demonstrate that GeO2 additive effectively promotes the generation of peculiar luminescent centers.

2007 ◽  
Vol 22 (7) ◽  
pp. 1954-1958 ◽  
Author(s):  
Jinjun Ren ◽  
Jianrong Qiu ◽  
Danping Chen ◽  
Chen Wang ◽  
Xiongwei Jiang ◽  
...  

Infrared (IR) luminescence covering 1.1 to ∼1.6 μm wavelength region was observed from bismuth-doped barium silicate glasses, excited by a laser diode at 808 nm wavelength region, at room temperature. The peak of the IR luminescence appears at 1325 nm. A full width half-maximum (FWHM) and the lifetime of the fluorescence is more than 200 nm and 400 μs, respectively. The fluorescence intensity increases with Al2O3 content, but decreases with BaO content. We suggest that the IR luminescence should be ascribed to the low valence state of bismuth Bi2+ or Bi+, and Al3+ ions play an indirect dispersing role for the infrared luminescent centers.


2015 ◽  
Vol 645-646 ◽  
pp. 1087-1092 ◽  
Author(s):  
Cui Yun Peng ◽  
Meng Jie Wei ◽  
Rong Juan Huang ◽  
Kun Ping Guo ◽  
Yue Lin Jing ◽  
...  

We have theoretically and experimentally investigated the microcavity organic light-emitting diodes (MOLEDs) that enhanced the emission intensity and narrowed the spectra simultaneously. In this work, MOLEDs with the reflectivities of 70% and 90% have been successfully fabricated. Comparing to non-cavity OLEDs, the maximum forward electroluminescence intensity and the peak luminescence can be improved by 6.8 times and 2.2 times, respectively. The full width at half maximum could be sharply narrowed to 10 nm. The different configurations of MOLEDs with varied emitting layers have also been evaluated which fitted well with the experimental results.


2021 ◽  
Vol 24 (1) ◽  
pp. 1-8
Author(s):  
M.A. Urbina-Yarupetan ◽  
J.C. González

We present the experimental results of optical analysis of nanostructured ZnO thin films grown onto commercial glass by reactive sputtering. Films with 20, 50, and 100 nm in thickness were analyzed by micro-Raman and micro-photoluminescence spectroscopies. Raman and photoluminescence bands were deconvoluted with Lorentzian profiles, in order to obtain information about response of films to excitation with laser light, occurring changes in position, full width half maximum (FWHM), and area of each phonon and emission bands of ZnO, correlating them with its nanostructure nature, and packing morphology of ZnO nanocolumns.


1995 ◽  
Vol 408 ◽  
Author(s):  
José Pedro Rino ◽  
Gonzalo Gutiérrez ◽  
Ingvar Ebbsjö ◽  
Rajiv K. Kalia ◽  
Priya Vashishta

AbstractUsing the molecular dynamics (MD) method, we have studied the effect of pressure on the distribution of rings and their relationship to intermediate range correlations manifested as the first sharp diffraction peak (FSDP) for Si02 glass. A systematic analysis of the modifications observed in the FSDP for densities ranging from 2.0 to 3.2 g/cm3 and temperatures from 0 to 1500 K is reported. The decrease in the height of the FSDP with increasing density is found to be proportional to the decrease in the number of 6-fold rings. For the density and temperature ranges studied in SiO2 glass, the full width at half maximum (FWHM) of the FSDP remains unchanged.


2021 ◽  
Vol 11 (15) ◽  
pp. 6919
Author(s):  
Majid Masnavi ◽  
Martin Richardson

A series of experiments is described which were conducted to measure the absolute spectral irradiances of laser plasmas created from metal targets over the wavelength region of 123–164 nm by two separate 1.0 μm lasers, i.e., using 100 Hz, 10 ns, 2–20 kHz, 60–100 ns full-width-at-half-maximum pulses. A maximum radiation conversion efficiency of ≈ 3%/2πsr is measured over a wavelength region from ≈ 125 to 160 nm. A developed collisional-radiative solver and radiation-hydrodynamics simulations in comparison to the spectra detected by the Seya–Namioka-type monochromator reveal the strong broadband experimental radiations which mainly originate from bound–bound transitions of low-ionized charges superimposed on a strong continuum from a dense plasma with an electron temperature of less than 10 eV.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Adam Huang ◽  
Chung-Wei Lee ◽  
Hon-Man Liu

AbstractMoyamoya disease (MMD) is a chronic, steno-occlusive cerebrovascular disorder of unknown etiology. Surgical treatment is the only known effective method to restore blood flow to affected areas of the brain. However, there are lack of generally accepted noninvasive tools for therapeutic outcome monitoring. As dynamic susceptibility contrast (DSC) magnetic resonance imaging (MRI) is the standard MR perfusion imaging technique in the clinical setting, we investigated a dataset of nineteen pediatric MMD patients with one preoperational and multiple periodic DSC MRI examinations for four to thirty-eight months after indirect revascularization. A rigid gamma variate model was used to derive two nondeconvolution-based perfusion parameters: time to peak (TTP) and full width at half maximum (FWHM) for monitoring transitional bolus delay and dispersion changes respectively. TTP and FWHM values were normalized to the cerebellum. Here, we report that 74% (14/19) of patients improve in both TTP and FWHM measurements, and whereof 57% (8/14) improve more noticeably on FWHM. TTP is in good agreement with Tmax in estimating bolus delay. Our study data also suggest bolus dispersion estimated by FWHM is an additional, informative indicator in pediatric MMD monitoring.


2016 ◽  
Vol 09 (02) ◽  
pp. 1650023 ◽  
Author(s):  
Bin Peng ◽  
Jianying Jiang ◽  
Guo Chen ◽  
Lin Shu ◽  
Jie Feng ◽  
...  

Highly c-axis oriented aluminum nitrade (AlN) films were successfully deposited on flexible Hastelloy tapes by middle-frequency magnetron sputtering. The microstructure and piezoelectric properties of the AlN films were investigated. The results show that the AlN films deposited directly on the bare Hastelloy substrate have rough surface with root mean square (RMS) roughness of 32.43[Formula: see text]nm and its full width at half maximum (FWHM) of the AlN (0002) peak is [Formula: see text]. However, the AlN films deposited on the Hastelloy substrate with Y2O3 buffer layer show smooth surface with RMS roughness of 5.46[Formula: see text]nm and its FWHM of the AlN (0002) peak is only [Formula: see text]. The piezoelectric coefficient d[Formula: see text] of the AlN films deposited on the Y2O3/Hastelloy substrate is larger than three times that of the AlN films deposited on the bare Hastelloy substrate. The prepared highly c-axis oriented AlN films can be used to develop high-temperature flexible SAW sensors.


2016 ◽  
Vol 34 (4) ◽  
pp. 675-686 ◽  
Author(s):  
Z.-L. Pan ◽  
J.-H. Yang ◽  
X.-B. Cheng

AbstractAn anti-resonance pulse forming network (PFN) has been designed, analyzed, and tested for its application in generating quasi-square pulses. According to the circuit simulations, a compact generator based on two/three-section network was constructed. Two-section network is applied in the generator due to its compact structure, while three-section network is employed for generating pulses with higher quality. When two-section network is applied in the generator, the full-width at half-maximum of the load pulse is 400 ns, at the same time, its rise time, flat top and fall time are 90, 180 and 217 ns, respectively. When the three-section network is applied with the same pulse width of the load pulse, the rise time of the output decreases to 60 ns, while the flat top increases to 240 ns and the fall time reduces to 109 ns. Meanwhile, this kind of network could be used to shape the output pulses of generators whose equivalent circuit is LC series discharge network, such as MARX generator, into quasi-square pulses. And the preliminary experiment demonstrates that anti-resonance network could work well on four-stage Marx generators. A sine pulse generated by the four-stage Marx generator is shaped into a quasi-square pulse with voltage of 11.8 kV and pulse width about 110 ns based on two-section anti-resonance network.


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