Abstract

TiO₂ doped silica single-mode waveguides,¹ produced by a combination of flame hydrolysis deposition (FHD) and reactive ion etching (RIE) on Si substrates, have been used in constructing various guided-wave optical devices. In some of these devices, such as ring resonators² and multichannel optical frequency selection switches,³ the effective waveguide lengths reach several tens of centimeters. Therefore, the device performances are strongly restricted by a waveguide loss of around 0.3 dB/cm in the existing SiO₂-TiO₂ system. We give the first report (to our knowledge) on drastic loss reduction in long silica based waveguides by replacing TiO₂ dopant with GeO₂.

© 1990 Optical Society of America