Optical and structural investigation on the energy transfer in a multicomponent glass co-doped with Si nanoaggregates and Er3+ ions

The enhancement of the Er3+ ions photoluminescence (PL) emission at 1.54 μm in a Si and Er co-implanted aluminosilicate glass is investigated in details. Post-implantation annealing has been performed to recover the damage induced by the implantation process and to promote Si aggregation. It is shown that 1h treatment in N2 atmosphere is not sufficient to induce Si precipitation for the investigated temperatures, up to 500°C. Nevertheless, the most intense Er3+ PL emission at 1.54 μm is achieved at 400°C. Such emission has been investigated by pumping in and out of resonance. The results suggest that good energy transfer mediators could be small Si aggregates and not only crystalline clusters. The effective excitation cross section of Er3+ ions has been measured in the best performing sample yielding a value of ~ 2 x 10-16 cm2, many orders of magnitude higher than the direct absorption cross section of Er3+ ions: about 10-21 cm2 in this glass. The structural and optical properties of this material are discussed and compared to those found for a standard silica substrate.