Upconversion Luminescence with Adjustable Multi-Color in Rare Earth Co-Doped Transparent Oxyfluoride Glasses

摘要

Transparent oxyfluoride glasses with highly efficient upconversion (UC) luminescence were developed in the 47.4SiO2- 19Al2O3- 28.4CaF2- xTbF3- 0.1TmF3- 3.2YbF3- (2-x)GdF3 composition, in mol%. The colors of upconversion luminescence could be tuned easily by adjusting the excitation power of laser and concentration of doped rare earth ions simultaneously. The relationship between the emission intensity of Tb3+/Tm3+/Yb3+ -codoped oxyfluoride glasses and the excitation pump power revealed that three-photon and two-photon absorption predominated in the conversion process from the infrared into blue and red luminescence, respectively. And a novel UC mechanism of red emission from Tm3+ is proposed and discussed.