Er3+-doped silica-titania based planar waveguides with a composition 72SiO(
2)-18TiO(2)-9AlO(1.5)-xErO(1.5)-yYbO(1.5) (in mol%) have been prepared by s
ol-gel processing, using multilayer spin-coating deposition on silica glass
or silica-buffered single crystal Si substrates. Their optical properties
were measured, including the measurement of the refractive index at 633 nm
by ellipsometry, the optical loss by prism coupling at different wavelength
s and the Er3+ fluorescence spectra and lifetimes at 1.54 mu m. The optical
loss at 633 nm variedfrom ca. 0.7 to 1.0 dB/cm, the Er3+ emission at 1.54
mu m had a full width at half maximum of similar to 55 nm and the correspon
ding lifetimes varied between 3 and 6 ms, depending on the Er concentration
and the residual OH level in the films, which was estimated by FTIR to be
less than 200 ppm in the best cases. (C) 1999 Elsevier Science B.V. All rig
hts reserved.