Laser-diode-excited blue upconversion in Tm3+/Yb3+ -codoped TeO2-Ga2O3-R2O (R=Li, Na, K) glasses.

This paper reports on intense blue upconversion in Tm(3+)/Yb(3+) codoped TeO(2)-Ga(2)O(3)-R(2)O(R=Li, Na, K) glasses upon excitation with commercial available laser diode (LD). Effects of alkali ions on the Raman spectra, thermal stability and spectroscopic properties of the tellurite-gallium glasses have also been investigated. Energy transfer and the involved upconversion mechanisms have been discussed.