In summary, intense UC and NIR emissions have been investigated in Er3+/Yb3+ co-doped transparent phosphate glass ceramics containing ErPO4 and YbPO4 nanocrystals under 975 nm LD excitation.
The temperature-dependences of optical properties of the glass ceramic have been demonstrated. As the temperature increases (298–450 K), the intensities of 1545, 652 and 550 nm decrease whereas the 523 nm emission intensity increases slightly, and the lifetime of Er3+:4I13/2 level decreases from 8.09 to 6.55 ms. Furthermore, the lifetime of Er3+:4I13/2 level also decreases with the increasing of pump power. All the experimental results can be explained based on analysis of transition of Er3+/Yb3+ codoped system, and the evolution of lifetime of Er3+:4I13/2 level at different temperature is fitted using multiphonon relaxation theory.These results will be helpful to further optimize parameters
of lasers materials and high gain fiber devices