Effect of pressure on luminescence properties of Sm3+ ions in potassium niobate tellurite glass

Emission spectra and decay properties of the 4G5/2 level of Sm3+ ions in TeO2+K2O+Nb2O5 glass have been measured as a function of pressure upto 14.6 GPa at room temperature. A progressive red shift in the barycentres of 4G5/2→6HJ (J=9/2, 7/2 and 5/2) emission bands and increase in splitting of these bands have been observed with increasing pressure. The luminescence decay profile of the 4G5/2 level at ambient condition shows a nearly single exponential nature and with increase in pressure it becomes gradually non-exponential associated with a decrease in lifetime. The non-exponential decay curves are well-fitted to the Inokuti–Hirayama model for S=6, indicating that the interaction for cross-relaxation energy transfer between Sm3+ ions is of dipole–dipole type. The results obtained after release of pressure reveal that there is a small hysteresis.