On optical activity of Er 3 + ions in Si-rich Si O 2 waveguides

Photoluminescence spectroscopy was used to explore the optical activity of Er 3 + ions in Si-rich Si O 2 waveguides prepared by ion implantation. Measurements were performed for a series of materials characterized by different Si excess levels, Er concentrations, and annealing temperatures. The highest fraction of optically active Er 3 + ions which can be efficiently activated by nonresonant pumping was found to be 2.6%. This was realized in a waveguide with an Er concentration of [ Er ] = 10 18 cm − 3 and Si excess of 20%, annealed at 900 ° C . This optical activity level is insufficient to realize optical gain. It is therefore clear that further material improvement is needed before optical amplification in Si O 2 : Er matrices sensitized by Si nanocrystals/nanoclusters can be achieved.