Article

Radiation Effects on Silica-Based Preforms and Optical Fibers—I: Experimental Study With Canonical Samples

CEA DIF, Arpajon
IEEE Transactions on Nuclear Science (Impact Factor: 1.22). 01/2009; DOI: 10.1109/TNS.2008.2007297
Source: IEEE Xplore

ABSTRACT Prototype samples of preforms and associated fibers have been designed and fabricated through MCVD process to investigate the role of fluorine (F) and germanium (Ge) doping elements on the radiation sensitivity of silica-based glasses. We characterized the behaviors of these canonical samples before, during and after 10 keV X-ray irradiation through several spectroscopic techniques, to obtain global information (in situ absorption measurements, electron paramagnetic resonance) or spatially-resolved information (confocal microscopy, absorption and luminescence on preform). These tests showed that, for the Ge-doped fiber and in the 300-900 nm range, the radiation-induced attenuation (RIA) can be explained by absorption bands associated with the following radiation-induced point defects: Ge(l); Ge-NBOHC and GeX. Other defects such as GeE' Ge(2); and Ge-ODC are generated but do not contribute in this spectral domain. For the F-doped sample, the different point defects identified, SiE', Si-NBOHC and Si-ODC(II), are unable to reproduce the RIA spectra for energies lower than 4 eV. We suggest that the radiation-induced absorption in this part of the spectrum is due to chlorine-related species, probably CI0 radiolytic groups that absorb at around 3.5 eV. The comparison between the sensitivities of the preform and the fiber reveals the influence of the drawing process on the glass response. Its effect is strongly dose-dependent for the germanosilicate glass. The drawing process seems to be responsible for the main part of the defects generated at low doses (<1 Mrad).

1 Bookmark
 · 
162 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We have investigated the thermoluminescent response of three Germanium-doped silica-based optical fibers obtained by varying the drawing parameters from a unique preform. We compared under X-ray irradiation, their dosimetric properties to those of two widely used commercial dosimeters based on different technologies. Then, we investigated the potential of these optical fibers to monitor gamma rays at different doses and dose-rates, and to different fluences of particles (0.8 and 14 MeV neutrons and 63 MeV protons). Our results show that the thermoluminescence response of the Ge-doped optical fibers depends linearly on the direct ionizing dose (gamma-, X-rays) or on the indirect ionizing dose (protons, neutrons). As a consequence, this class of fibers is an excellent candidate for passive dosimetry in various fields from medical applications to high-energy physics.
    IEEE Transactions on Nuclear Science 01/2013; 60(6):4251-4256. · 1.22 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We investigate the response of Ge-doped, P-doped, pure-silica, or Fluorine-doped fibers to extreme environments combining doses up to MGy(SiO$_{{{2}}}$) level of 10 keV X-rays and temperatures between 25$~^{circ}!{hbox{C}}$ and 300$~^{circ}!{hbox{C}}$. First, we evaluate their potential to serve either as parts of radiation tolerant optical or optoelectronic systems or at the opposite, for the most sensitive ones, as punctual or distributed dosimeters. Second, we improve our knowledge on combined ionizing radiations and temperature (R&T) effects on radiation-induced attenuation (RIA) by measuring the RIA spectra in the ultraviolet and visible domains varying the R&T conditions. Our results reveal the complex response of the tested fibers in such mixed environments. Increasing the temperature of irradiation increases or decreases the RIA values measured at 25$~^{circ}!{hbox{C}}$ or sometimes has no impact at all. Furthermore, R&T effects are time dependent giving an impact of the temperature on RIA that evolves with the time of irradiation. The two observed transient and stationary regimes of temperature influence will make it very difficult to evaluate sensor vulnerability or the efficiency of hardening approaches without extensive test campaigns.
    IEEE Transactions on Nuclear Science 01/2013; 60(6):4305-4313. · 1.22 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Effect of gamma-ray irradiation on magneto-optic characteristics of Cu-doped optical fiber was investigated. Verdet constant at 660 nm under magnetic field of 0.142 T of the optical fiber increased about 1.46 times after the irradiation.
    OptoElectronics and Communications Conference held jointly with 2013 International Conference on Photonics in Switching (OECC/PS), 2013 18th; 01/2013

Full-text (2 Sources)

Download
429 Downloads
Available from
May 26, 2014