and observation of fibers under the electron microscope allowed to clearly state that
the observed phenomenon is the effect of reduction of Ag
+ ions on the surface of
the glass fiber. This phenomenon is related to the mechanism of self-organization of
silver molecules inside the glass structure under thermal conditions above the
transformation temperature T g . The absorption spectrum (Fig. 14.16) clearly shows
the band at a wavelength of 450 nm obtained for a fiber annealed for 2 h. The inset
in Fig. 14.16 presents optical fiber images acquired before and after the annealing
process.
A visual confirmation of the described effect is shown in the SEM images
(Fig. 14.17). Based on observations, the described effect occurred only in glasses
Fig. 14.15 Luminescence spectra of SGB glasses, doped with 0.1Ag/0.2Eu and optical fibers
(inset) for different annealing times
Fig. 14.16 Luminescence
spectra of SGB glasses, doped
with 0.1Ag/0.2Eu and optical
fibers (inset) for different
annealing times
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