To understand R110079 (Eu), let us consider . The researchers studied Eu2O3 doped 5ZnO-20Nb2O5-75TeO2 glasses. In this case, "Raman spectra show that Eu2O3 dopant induces the changes in the local structure of glasses. The higher the dopant concentration, the larger the nonlinear refractive n2 and the faster the temporal response. The Figure , and their intensity increase with the increasing Eu2O3 concentration". In our Figure , the large peak is at about 2480 cm -1 . In the Figure by Zhao et al., we can see also a peak at 4532.5 cm -1 . In our Figure , the peak is at about 4582 cm -1 .