Blue and green upconversion emission of Tm3+/ Yb3+ /Ag-doped germinate-tellurite glasses at 808nm excitation

Germinate- tellurite glasses of composition TeO2-Li2O-WO3-Ge2O-Yb2O3-Tm2O3-Ag2O (TWLGTYA) are synthesized by the melt-quenching method. In these glasses Ag nanoparticles (AgNPs) growth was controlled by reheating above the glass temperature. The absorption spectrum of the samples is measured for identification of the different absorption level of Tm3+ and Yb3+ ions. The intense blue band at 456nm emission of Tm3+ ions under 808nm excitation is investigated without AgNPs samplesTWLGTY7. For 0.7 mol% of Ag2O with 7hrs reheat-treated TWLGTYA samples is attributed to the enhanced 537nm emission corresponding to transition 1D2→ 3F4 due to the local field on the Tm3+ ions locations. It shows that due to presence of Ag NPs, significantly enhance the 537nm emission Tm3+ ions by surface plasmon resonance (SPR). Also incorporation of Yb3+ into TWLGTYA glass can effectively improve the blue 456 nm emission could be useful in the field of sensor materials.