Search results for "silica."
showing 10 items of 1087 documents
Paramagnetic germanium-related centers induced by energetic radiation in silica based devices
2009
In-situ observation of β-ray induced optical absorption in a-SiO2: radiation darkening and room temperature recovery
2008
The structural disorder of a silica network probed by site selective luminescence of the nonbridging oxygen hole centre
2011
We studied the inhomogeneous distribution of the luminescence band associated with the nonbridging oxygen hole centre in silica through site selective excitation/detection of the zero phonon line by a tunable laser source. Defects induced in the bulk of synthetic samples by γ and β exposure exhibit an increase of the inhomogeneous width from 0.071 to 0.086 eV on increasing the irradiation dose from 2 × 10(6) to 5 × 10(9) Gy. We also investigated two defect variants stabilized at the surface of the silica nanoparticles, (≡ Si-O)3 Si–O* and (≡ Si-O)2(H-O)Si-O*, whose inhomogeneous width was measured to be 0.042 eV and 0.060 eV, respectively. These results can be accounted for by the structura…
Radiation induced generation of Non-Bridging Oxygen Hole Center: intrinsic and extrinsic processes
2006
Bright blue emission of synthesized silica nanoparticles conferred by surface defects
2013
Phonon Coupling Properties of Non Bridging Oxygen Hole Centers at a Silica Surface Probed by Site-Selective Luminescence Excitation
2008
Luminescenza risolta in tempo del non bridging oxygen hole center in silice: proprietà di volume e di superficie
2007
Photoluminescence properties of point defects in Ge-doped fibers and preforms
2008
International audience; The optical properties of Ge-related point defects are often the most important parameter for the performances of silica based optical fibers. On one side their presence is often detrimental for the light transmission, on the other side some defect typologies exhibit modifications under radiation exposure thus offering the peculiar property of photosensitivity that is exploited to build technologically relevant devices such as fiber Bragg gratings.
10-keV X-ray irradiation effects on phosphorus doped fibers and preforms: electron spin resonance and optical studies
2009
Stability of sol-gel silica glass for CPV and ultraviolet LED applications
2011
This paper concerns the characterization of silica glass obtained by a sol-gel technique as to its suitability in the terrestrial and space concentrated photovoltaic (CPV), and ultraviolet light emitting diode (UV LED) industrial sectors. The sol-gel material tested is produced by Evonik Industries and marketed under the brand name SAVOSIL™. The tests performed were aimed at determining the endurance of the material to radiation exposure and consist of exposure to gamma radiation and 355 nm UV laser light. In these tests the transmittance of the glass was measured before and after the exposure to the radiation to determine the effect of the radiation treatment. In the case of the test with …