865814.fig.005a
(a)
865814.fig.005b
(b)
Figure 5: (a) Photoluminescence spectra of Fe-MG SiO2 glasses (F1M1, F2M1, F3M1, and F4M1) and M1 glass. (b) Variation of photoluminescence intensity with molar concentration of Fe-I in F M1 glasses ( ).