Strip-loaded high-confinement waveguides for photonic applications

Sol-gel is a promising deposition technique for the fabrication of silica-o n-silicon photonic components. Silica-titania compositions provide large in dex differences, and thus strong mode confinement, and are suitable hosts f or Er-doped optical amplifiers. We have developed channel waveguides based on phosphosilicate strip loads over high index titania-doped guiding layers . Here we demonstrate that low propagation loss (0.3 dB/cm) can be obtained in such guides at optical communication wavelengths. Alumina co-doped guid ing layers are Shown to inhibit OH retention without causing titania segreg ation, and reduced humidity during spinning is shown to be necessary to ach ieve low propagation losses.