Patent ID: 6718109
Filing Date: 2004-04-06
Classification: G02B

Abstract:
An optical waveguide (1) with a multi-layer waveguide core (7), the waveguide (1) comprising;a substrate (2); a waveguide core (7) formed on the substrate (2); and at least one upper cladding layer (a) embedding said waveguide core (7), the waveguide core (7) having been etched from a composite core layer (6) and comprising: a first core layer (4) with a softening temperature T1S formed on the substrate (2); and at least one other core layer (5) formed on the first core layer (4), wherein the softening temperature T1S of at least the uppermost one of said at least one other core layers (5) is less than the softening temperature T1S of an underlying core layer (4,5) which has a greater thickneses than said uppermost core layer.