MICROSTRUCTURE AND OPTICAL PROPERTIES OF ERBIUM DOPED SILICA-BASED FILMS VIA FLAME HYDROLYSIS DEPOSITION AND AEROSOL DOPING

Silica-based films on Si fabricated by flame hydrolysis deposition were doped with erbium ions using an aerosol doping technique, and co-doped with GeO 2, P 2 O 5 and B 2 O 3. The erbium solution concentration was varied from 4 to 8wt%. The results show that the refractive index of the films is not changed with erbium addition and no OH group is detected for erbium doped silica-based films. An obvious peak was observed at 1.542 µm with the FWHM of 65 nm, which corresponds to the 4 I 13/2 → 4 I 15/2 transition. With the increase of Er solution concentration, the photoluminescence (PL) intensity first increases, then decreases above 6 wt % Er solution concentration. The decrease in PL intensity with concentration is attributed to concentration quenching caused by Er - Er interaction. The dependence of PL intensity on pump power intensity further confirms the concentration quenching is cooperative upconversion.

UV-Irradiation-Induced Refractive Index Increase of Ge-Doped Silica Films

Ge-doped silica glass films were fabricated on Si (100) substrates for core materials of waveguide using flame hydrolysis deposition. Then the films were hydrogen loaded and irradiated to KrF excimer laser. The refractive indices and extinction coefficients of the samples before and after irradiation were determined using M-2000 variable angle incidence spectroscopic ellipsometer (VASE) and obtain the maximum increase about 0.3% at 1550 nm.