Eu3+ And Er3+ doped SiO2 - TiO2 sol-gel films for active planar waveguides

Sol-gel films of SiO2 - TiO2 doped with Eu3+ or Er3+ ions were prepared by spin-coating with a variety of molar concentration ratios of tetraethoxysilane (TEOS) and titanium isopropoxide (TPOT). The ratios of SiO2 - TiO2 are 90/10, 85/15, 80/20, 75/25 and the concentrations of Eu and Er ions varied from 10-3 to 5.10-2 mol %. Silica-titania films annealed from 150 up to 900°C decreased their thickness from 300 to 150 nm and increased the refractive index from 1.49 to 1.62. The multilayer (6-8 layers) silica-titania thin films with thickness about 1.2 - 1.6 mm have been developed in order to make highly doped Eu3+ or Er3+ planar wave guides on silicon substrates. Luminescence spectra, lifetimes as well as FTIR and micro-Raman spectra have been measured. The influence of active ion concentrations and annealing temperature on the luminescence properties and the structure of thin films were investigated.