Broadband NIR Emission in Sol-Gel Er~(3+)-Activated SiO_2-Ta_2O_5 Glass Ceramic Planar and Channel Waveguides for Optical Application

摘要

An Er~(3+)-doped SiO_2:Ta_2O_5 optical channel waveguide and nanocomposite were prepared by the sol-gel route at a Si:Ta 50:50 molar ratio. Channels with an excellent surface profile were easily and quickly fabricated by focusing a femtosecond laser onto the surface of multilayered films deposited on SiO_2/Si substrates. In parallel, the same sol used to prepare the film was annealed at 900, 1000, and 1100℃ for 2 h, to get the nanocomposite materials. A broadband NIR emission around 1538 nm, assigned to the ~4I_(13/2)→~4I_(15/2) transition of the Er~(3+) ions was observed in the nanocomposites of amorphous SiO_2 containing dispersed Ta_2O_5 nanocrystals. The ~4I_(13/2) lifetime and emission bandwidth depend on the annealing temperature. In conclusion, Er~(3+)-doped SiO_2:Ta_2O_5 channel waveguides and nanocomposites are promising materials for photonic applications.