Frequency up-conversion luminescence properties and mechanism of Tm super(3+)/Er super(3+)/Yb super(3+) co-doped oxyfluorogermanate glasses

Oxyfluoride glasses were developed with composition 60GeO sub(2).10AlF sub(3).25BaF sub(2).(1.95-x) GdF sub(3). 3YbF sub(3).0.05TmF sub(3) .xErF sub(3) (x = 0.02, 0.05, 0.08, 0.11, 0.14, 0.17) in mole percent. Intense blue (476 nm), green (524 and 546 nm) and red (658 nm) emissions which identified from the super(1) G sub(4) arrow right super(3) H sub(6) transition of Tm super(3+) and the ( super(2) H sub(11/2), super(4) S sub(3/2)) arrow right super(4) I sub(15/2), super(4) F sub(9/2) arrow right super(4) I sub(15/2) transitions of Er super(3+), respectively, were simultaneously observed under 980 nm excitation at room temperature. The results show that multicolor luminescence including white light can be adjustably tuned by changing doping concentrations of Er super(3+) ion or the excitation power. In addition, the energy transfer processes among Tm super(3+), Er super(3+) and Yb super(3+) ions, and up-conversion mechanisms are discussed.