Enhanced Optical Properties of Germanate and Tellurite Glasses Containing Metal or Semiconductor Nanoparticles
Figure 8
Energy level diagram of Er3+ and Yb3+ ions illustrating possible upconversion pathways for Er3+/Yb3+ codoped glasses. The solid straight lines with upward and down arrows indicate optical transitions; dotted lines and wavy arrows denote ET processes and non-radiative relaxation, respectively [2].
