“…As a manifestation to this fact, we would like to bring the attention to the fact that the samples in this work were processed using sol-gel techniques, and that the transitions indicated on page 238 of reference [41] were for Er-doped aluminosilicate, while the ones in the work of Abedrabbo et al in references [42,43] were for ion beam mixing of Er, Si and O and for Er, Si, O and Ge, and all of them shared similar transitions. The ion beam mixing effort of this group started earlier without Er impurity centers as in references [44,45] and was consolidated with rare-earth inclusions. As a matter of fact, it is noteworthy to state that the transitions approximately corresponded to 1480 nm, 1500 nm, 1516 nm, 1535 nm and 1550 nm, and 1487 nm, 1511 nm, 1538 nm and 1551, respectively.…”