Different index contrast silica-on-silicon waveguides by PECVD

Ge-doped silica-on-silicon waveguides with index steps of 0.01 and 0.02 were fabricated by a combination of plasma enhanced chemical vapour deposition (PECVD) and reactive ion etching (RIE) techniques, and their characteristics, including propagation loss, coupling loss with standard singlemode fibres, minimal bend radius, and birefringence, were investigated. The waveguides have good propagation properties and small birefringence, compared to using flame hydrolysis deposition (FHD).