Formation of Drawing- or Radiation-Induced Defects in Germanium-Doped Silica Core Optical Fiber

1994 ◽  
Vol 33 (Part 2, No. 2B) ◽  
pp. L233-L234 ◽  
Author(s):  
Yoshinori Hayashi ◽  
Yuki Okuda ◽  
Hisamitsu Mitera ◽  
Keizo Kato
1986 ◽  
Vol 88 ◽  
Author(s):  
T. Wei ◽  
M. P. Singh ◽  
W. J. Miniscalco ◽  
J. A. Wall

ABSTRACTWe have investigated the relationship of precursor defects in as-drawn optical fiber to glass composition and processing conditions in order to understand the radiation sensitivity of doped-core optical fiber. Techniques are reported for improving the radiation hardness of graded-index multimode fibers through reducing the concentration of doping- and processing-induced defects as well as modifying the residual defects in as-drawn fiber. Significant decreases in radiation-induced loss have been observed for fibers pretreated with hydrogen. An investigation of the role of drawing-induced defects indicates that a lower draw temperature produces slightly harder fiber. A study of core/clad interfacial stress revealed that such stress does not play a major role in radiation sensitivity.Measurement techniques included in situ loss measurements at 850 nm and spectral loss measurements before and after -γ irradiation. In addition, photoluminescence proved to be an effective tool for characterizing specific defect centers. It was found for Ge/P-codoped fibers that the luminescence band at 650 nm attributed to drawing/radiation induced centers has an inverse correlation with induced loss. Previously unreported emission bands have been observed, including one at 720 nm which may be related to fluorine doping.


Author(s):  
H. Watanabe ◽  
B. Kabius ◽  
B. Roas ◽  
K. Urban

Recently it was reported that the critical current density(Jc) of YBa2Cu2O7, in the presence of magnetic field, is enhanced by ion irradiation. The enhancement is thought to be due to the pinning of the magnetic flux lines by radiation-induced defects or by structural disorder. The aim of the present study was to understand the fundamental mechanisms of the defect formation in association with the pinning effect in YBa2Cu3O7 by means of high-resolution electron microscopy(HRTEM).The YBa2Cu3O7 specimens were prepared by laser ablation in an insitu process. During deposition, a substrate temperature and oxygen atmosphere were kept at about 1073 K and 0.4 mbar, respectively. In this way high quality epitaxially films can be obtained with the caxis parallel to the <100 > SrTiO3 substrate normal. The specimens were irradiated at a temperature of 77 K with 173 MeV Xe ions up to a dose of 3.0 × 1016 m−2.


1986 ◽  
Vol 47 (C8) ◽  
pp. C8-1045-C8-1048
Author(s):  
T. BOLZE ◽  
J. PEISL

1989 ◽  
Vol 32 (3) ◽  
pp. 198-203
Author(s):  
A. N. Georgobiani ◽  
M. B. Kotlyarevskii ◽  
B. P. Dement'ev ◽  
V. N. Mikhalenko ◽  
N. V. Serdyuk ◽  
...  

1969 ◽  
Vol 30 (4) ◽  
pp. 253-254 ◽  
Author(s):  
I.R. Nair ◽  
C.E. Hathaway

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