Cooperative downconversion in Yb3+–RE3+ (RE=Tm or Pr) codoped lanthanum borogermanate glasses

摘要

We report on cooperative downconversion in Yb –RE (RE=Tm or Pr) codoped lanthanum borogermanatenglasses (LBG), which are capable of splitting a visible photon absorbed by Tm3+ or Pr3+ ions into two near-ninfrared photons. The results indicate that Pr3+–Yb3+ is a more efficient ion couple than Tm3+–Yb3+ innterms of cooperative downconversion. We have obtained a highest quantum yield of 165% and 138% fornPr3+–Yb3+ and Tm3+–Yb3+ codoped LBG glasses under 468 nm excitation, respectively. However, ultravio-nlet light excitation to the charge transfer band of Yb3+ does not result in quantum splitting as rapid relax-nation from the charge transfer band to 4fn13 levels of Yb3+ dominates. © 2008 Optical Society of America