Gamma and UV Radiation-Induced Color Centers in Optical Fibers

Radiation-induced losses and paramagnetic centers were investigated in phosphorusdoped and P-free multimode germanosilicate optical fibers after g-rays (~1 MeV) and ultraviolet (5 eV) exposures. After both types of irradiation, the same defects seem to be responsible of the fiber absorption in the spectral range 400 to 1650 nm. In particular, the P1 centers and the Phosphorus Oxygen Hole centers are created in both cases in the phosphorus-doped fibers and explain the high permanent radiation-induced attenuation levels observed in this fiber type. Luminescence and electron spin resonance measurements (77 K, ~9.38 GHz) on irradiated samples confirm that the GeE’, SiE’ and NBOHC defects are also generated in the different irradiated samples. From this study, it seems that the pertinence of a multimode fiber for nuclear space or civil applications could be estimated through low-cost ultraviolet measurements.

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Nonuniform distribution of oxygen hole centers in silica optical fibers

Applied Physics Letters ◽

10.1063/1.110139 ◽

1993 ◽

Vol 63 (25) ◽

pp. 3440-3442 ◽

Cited By ~ 4

Author(s):

S. Kannan ◽

M. E. Fineman ◽

J. Li ◽

G. H. Sigel

Keyword(s):

Optical Fibers ◽

Nonuniform Distribution ◽

Oxygen Hole ◽

Hole Centers

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Measurement of Optical Absorption in Very Thin Low-Loss SiO2 Films

MRS Proceedings ◽

10.1557/proc-105-175 ◽

1987 ◽

Vol 105 ◽

Cited By ~ 3

Author(s):

Robert M. Curran ◽

Thomas M. Crook ◽

J. David Zook

Keyword(s):

Thin Films ◽

Optical Absorption ◽

Optical Fibers ◽

Resonant Cavity ◽

Plasma Radiation ◽

Low Loss ◽

Plasma Irradiation ◽

Oxygen Hole ◽

Low Levels ◽

Hole Centers

AbstractWhile low levels of optical absorption are easily measured in SiO2 bulk samples or optical fibers, we present here a method of detirmining low levels of absorption in thin films of SiO2. Films are deposited on top of high reflectivity multi-layer miriors, and absorption is derived from the time decay in a resonant cavity of threj mirrorsgt 633 nm. Absorption coefficients on the order of 1 cm−1. (k = 10−5) can be measured in films as thin as 100 Angstroms.With this method, we find that absorption at 633 nm can be induced in SiO2 films by exposing them to a He-Ne plasma discharge. Although the plasma radiation (>10 eV) is absorbed near the SiO2 surface, the plasma-induced absorption is uniform within the SiO2 film. This was shown by plasma irradiation of SiO2 films of 4arying thickness, together with computer calgulation of the optical properties of multilayer thin films. Similar absorption behavior has been reported in SiO2 optical fibers and may be due here to DIA (Drawing-Induced Aisorption) centers or NBOHCs (Non-Bridging Oxygen Hole Centers).

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Radiation Effects on Pure Silica Core Optical Fibers by γ-Rays: Relation between 2 eV Band and Non-Bridging Oxygen Hole Centers

Japanese Journal of Applied Physics ◽

10.1143/jjap.25.464 ◽

1986 ◽

Vol 25 (Part 1, No. 3) ◽

pp. 464-468 ◽

Cited By ~ 61

Author(s):

Kaya Nagasawa ◽

Yutaka Hoshi ◽

Yoshimichi Ohki ◽

Kichinosuke Yahagi

Keyword(s):

Optical Fibers ◽

Radiation Effects ◽

Pure Silica ◽

Oxygen Hole ◽

Γ Rays ◽

Silica Core ◽

Hole Centers

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Structural and Optical Modifications in the BaO-ZnO-LiF-B2O3-Yb2O3 Glass System after γ-Irradiation

Materials ◽

10.3390/ma14226955 ◽

2021 ◽

Vol 14 (22) ◽

pp. 6955

Author(s):

Nimitha S. Prabhu ◽

Hiriyur Mallaiah Somashekarappa ◽

M. I. Sayyed ◽

Hamid Osman ◽

Sultan Alamri ◽

...

Keyword(s):

Trap Depth ◽

Structural Rearrangement ◽

Glass System ◽

Γ Irradiation ◽

Oxygen Hole ◽

Spin Resonance ◽

Before And After ◽

Radiation Induced ◽

The Fourier Transform ◽

Induced Defects

A Yb3+-doped borate glass system was examined for the structural and optical modifications after γ-irradiation. Among the studied 10BaO-20ZnO-20LiF-(50-x)B2O3-xYb2O3 (x = 0.1, 0.5, 0.7, and 1.0 mol%) glasses, the 10BaO-20ZnO-20LiF-49.9B2O3-0.1Yb2O3 glass showed the highest thermoluminescence intensity, trap density, and trap depth. The glass was irradiated with the optimum γ-dose of 1 kGy towards the analysis of radiation-induced defects. The amorphous nature was preserved before and after irradiation. The glass density slightly increased after irradiation. The structural rearrangement was evident from the Fourier transform infrared spectroscopy by the appearance and disappearance of some bonds after γ-irradiation. The transformation of [BO4] units into [BO3] units and non-bridging oxygens was deduced. The color of the glass darkened after irradiation and the optical absorption intensity enhanced between 250 and 700 nm. The optical bandgap reduced and Urbach energy increased upon γ-dose exposure. The electron spin resonance of the irradiated glass exhibited two signals at g = 2.0167 and g = 1.9938, corresponding to the non-bridging oxygen hole center and Boron E’-center, respectively.

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An electron spin resonance study of radiation‐induced electrically active paramagnetic centers at the Si/SiO2interface

Journal of Applied Physics ◽

10.1063/1.332171 ◽

1983 ◽

Vol 54 (3) ◽

pp. 1457-1460 ◽

Cited By ~ 140

Author(s):

P. M. Lenahan ◽

P. V. Dressendorfer

Keyword(s):

Electron Spin Resonance ◽

Electron Spin ◽

Electron Spin Resonance Study ◽

Paramagnetic Centers ◽

Spin Resonance ◽

Radiation Induced ◽

Spin Resonance Study

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Fundamental defect centers in glass: Electron spin resonance and optical absorption studies of irradiated phosphorus‐doped silica glass and optical fibers

Journal of Applied Physics ◽

10.1063/1.332591 ◽

1983 ◽

Vol 54 (7) ◽

pp. 3743-3762 ◽

Cited By ~ 275

Author(s):

D. L. Griscom ◽

E. J. Friebele ◽

K. J. Long ◽

J. W. Fleming

Keyword(s):

Electron Spin Resonance ◽

Optical Absorption ◽

Optical Fibers ◽

Electron Spin ◽

Silica Glass ◽

Defect Centers ◽

Spin Resonance ◽

Absorption Studies ◽

Phosphorus Doped

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New Phosphorus Oxygen Hole Center in Γ-Irradiated SiO2:P2O5 Optical Fiber

MRS Proceedings ◽

10.1557/proc-61-339 ◽

1985 ◽

Vol 61 ◽

Cited By ~ 5

Author(s):

H. Kawazoe ◽

M. Kohketsu ◽

Y. Watanabe ◽

K. Shibuya ◽

K. Muta

Keyword(s):

Optical Absorption ◽

Optical Fiber ◽

Room Temperature ◽

Hole Center ◽

Paramagnetic Centers ◽

Γ Irradiation ◽

Electron Center ◽

Oxygen Hole ◽

New Type ◽

Hole Centers

ABSTRACTThe formation of paramagnetic centers upon γ-irradiation was examined for the silica based waveguides doped with P2O5 by using ESR and optical absorption. The centers inherent in SiO2 glasses such as Si-E′ and OHC were found to be replaced with P-related centers such as phosphorus oxygen hole centers and phosphorus electron center by introducing a small amount of P2O5. New type of POHC was detected especially in the glass with [P2O5] of 1.3 mol % at 77K, which was assumed to be a precursor of the POHC stable at room temperature. The correlation between γ-induced loss-increase and the formation of these defects was examined.

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Radiation Effects on Pure-Silica Multimode Optical Fibers in the Visible and Near-Infrared Domains: Influence of OH Groups

Applied Sciences ◽

10.3390/app11072991 ◽

2021 ◽

Vol 11 (7) ◽

pp. 2991

Author(s):

Cosimo Campanella ◽

Vincenzo De Michele ◽

Adriana Morana ◽

Gilles Mélin ◽

Thierry Robin ◽

...

Keyword(s):

Optical Fibers ◽

Radiation Effects ◽

Near Infrared ◽

Signal Transmission ◽

Hydroxyl Groups ◽

Oh Groups ◽

Pure Silica ◽

Oxygen Hole ◽

Three Samples ◽

Radiation Induced

Signal transmission over optical fibers in the ultraviolet to near-infrared domains remains very challenging due to their high intrinsic losses. In radiation-rich environments, this is made even more difficult due to the radiation-induced attenuation (RIA) phenomenon. We investigated here how the number of hydroxyl groups (OH) present in multi-mode (MM) pure-silica core (PSC) optical fibers influences the RIA levels and kinetics. For this, we tested three different fiber samples: one “wet”, one “dry” and one with an intermediate “medium” OH content. The RIA of the three samples was measured in the 400–900 nm (~3 eV to ~1.4 eV) spectral range during and after an X-ray irradiation at a dose rate of 6 Gy(SiO2) s−1 up to a total accumulated dose of 300 kGy(SiO2). Furthermore, we evaluated the H2-pre-loading efficiency in the medium OH sample to permanently improve both its intrinsic losses and radiation response in the visible domain. Finally, the spectral decomposition of the various RIA responses allows us to better understand the basic mechanisms related to the point defects causing the excess of optical losses. Particularly, it reveals the relationship between the initial OH groups content and the generation of non-bridging oxygen hole centers (NBOHCs). Moreover, the presence of hydroxyl groups also affects the contribution from other intrinsic defects such as the self-trapped holes (STHs) to the RIA in this spectral domain.

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Uses of Radiation-Induced Paramagnetic Centers in Bone

Physiology ◽

10.1152/physiologyonline.1989.4.3.112 ◽

1989 ◽

Vol 4 (3) ◽

pp. 112-116 ◽

Cited By ~ 1

Author(s):

K Ostrowski ◽

A Dziedzic-Goclawska

Keyword(s):

Electron Spin Resonance ◽

Ionizing Radiation ◽

Bone Mineral ◽

Electron Spin ◽

Biological Markers ◽

Bone Grafts ◽

Crystalline Lattice ◽

Paramagnetic Centers ◽

Spin Resonance ◽

Radiation Induced

Ionizing radiation induces stable paramagnetic centers in the crystalline lattice of bone hydroxyapatite. These can be measured by electron-spin resonance spectrometry and can serve as biological markers for evaluation of crystallinity of bone mineral, quantitation of the rebuilding process of radiation-sterilized bone grafts, and estimation of doses of ionizing radiation.

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