Direct demonstration of sensitization at 980nm optical excitation in erbium-ytterbium silicates

Sensitization of erbium by ytterbium in Er
_x
Yb
_2-x
SiO
₅
thin films at 980nm optical excitation is demonstrated by means of comparison of the 1.54μm photoluminescence intensities excited with 488nm and 980nm light. Additionally, it is shown that detrimental Er-Er interactions such as concentration quenching increase non-radiative decay rates at high erbium concentrations. Dilution of erbium by ytterbium reduces these interactions, leading to an increase of internal quantum efficiency.