Room-temperature photoluminescence excitation spectroscopy of Er3+ ions in Er- and (Er+Yb)-doped SiO2 films

We apply photoluminescence excitation spectroscopy to study the efficiency of excitation at 960–990 nm of the 1.54 μm emission of erbium implanted into SiO2 films thermally grown on silicon for a range of Er and Yb concentrations. We show that, in silica films doped solely with Er, the concentration of Er should be lower than 1020 cm−3 to prevent efficient concentration quenching of the emission. It is shown that the Yb/Er concentration ratio of 1–2 is optimum for the dopant densities of 1–2×1020 cm−3, whereas 1021 cm−3 results in quenching of the emission due to energy losses within the Yb subsystem.