EN
Excitation of the intra-4f-shell luminescence near 1.5μm in silicon-rich silicon oxide is studied. Silicon-rich silicon oxide was produced by high dose implantation of Si^+ ions into SiO_2 layers grown on silicon. Erbium doping was also performed using implantation of Er^+ ions at an energy of 800 keV. An evidence is presented that transfer of energy from defects related to excess silicon in silica is the dominant mechanism of excitation of Er^{3+} for optical pumping in the UV-blue wavelength range. Si-nanocrystals created by annealing at 1100ºC rather compete for excitation with erbium than transfer energy to Er^{3+}.