US Patent 7290407 Triangle-shaped planar optical waveguide having reduced scattering loss

A method for forming an optical waveguide is disclosed. The method comprises first forming a lower cladding layer having at least one waveguide support. Next, a core material is formed onto the waveguide support using a high density plasma chemical vapor deposition (HDPCVD) process. Finally, an upper cladding layer is formed over the core material, such that the upper cladding layer and the lower cladding layer surround the core material.