Patent ID: 6949392

Claim:
A method for forming an integrated optical circuit comprising: providing a substrate; forming a first cladding layer having a first cladding refractive index on the substrate; forming a first core layer on the first cladding layer, the first core layer having a core refractive index; defining waveguiding elements in the first core layer; forming a second cladding layer having a second cladding refractive index on the waveguiding elements of the first core layer such that the first cladding layer and the second cladding layer encapsulate the waveguiding elements, the second cladding refractive index and the first cladding refractive index being less than the core refractive index, and wherein the second cladding layer is formed through simultaneous cladding material deposition and removal, the ratio of cladding material deposition to cladding material removal being approximately greater than 1 and less than 20 such that the second cladding layer is substantially void-free and substantially self-planarizing; wherein the forming of the first core layer and any subsequent processing is performed at a temperature less than approximately 500° C.