Investigation on three fundamental colors upconversion luminescence of Yb3+/Er3+/Tm3+-codoped oxyfluoride tellurite glass

A new Yb3+/Er3+/Tm3+-codoped oxyfluoride tellurite glass was prepared in this paper. Raman spectrum, absorption spectrum and, upconversion luminescence spectrum of ZnF2-modifted Yb3+/Er3+/Tm3+-codoped oxyfluoride tellurite glass were studied. The results show that the oxyfluoride tellurite glass has low phonon energy. The intense blue (476 nm), green (530 and 545 nm) and red (656 nm) emissions were simultaneously observed at room temperature under 980 nm LD excitation. Upconversion blue (476 nm) luminescence is due to the (1)G(4)-> H-3(6) transition of Tm3+, upconversion green (530 and 545 6m) and red (656 nm) luminescence are due to the 2H(11/2)-> I-4(15/2), S-4(3/2)-> I-4(15/2), and F-4(9/2)-> I-4(15/2) transitions of Er3+, respectively. According to absorption spectrum and energy levels of Yb3+/Er3+/Tm3+, the upconversion mechanisms of Yb3+/Er3+/Tm3+-codoped oxyfluoride tellurite glass were analyzed. It shows that upconversion blue luminescence is a three-photon absorption process, and both upconversion green and red luminescence are due to the two-photon absorption process. The results indicate that the oxyfluofide tellurite glass is potential material for realization of three-dimensional volumetric display.