Device including a substrate-supported optical waveguide, and method of manufacture
AssigneeAT&T Bell Laboratories
InventorsCharles H. Henry, Roland A. Levy
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Abstract
In the manufacture of optical devices such as, e.g., optical communications assemblies and optical gyroscopes, low-loss substrate-supported optical waveguides are desired. Such waveguides can be obtained by patterning a layer of deposited waveguide material and, in the interest of minimizing loss as may be due to processing-induced surface roughness, waveguides as patterned preferably undergo a heat treatment which results in surface smoothing and in rounding of the waveguide cross section. Furthermore, in the interest of avoiding re-entrant corners between substrate and waveguide, a wetting layer may be applied to the waveguide prior to heat treatment.
Claims12
A device comprising a substrate-supported optical waveguide, said waveguide comprising a waveguide core on a portion of a first waveguide cladding layer on a substrate,
- characterized in that a core-cladding wetting layer is on at least a portion of said first waveguide cladding layer adjoining the interface between said waveguide core and said cladding layer, said wetting layer consisting of a material which is essentially the same as the material of said waveguide core.
A method for making a device comprising a substrate-supported optical waveguide, said method comprising
- depositing a layer of waveguide core material on a layer of waveguide cladding material,
- selectively removing portions of said layer of core material to produce a pattern comprising said waveguide,
- providing a wetting layer on at least a portion of said waveguide cladding material adjacent to the interface between said cladding material and said core material, and
- smoothing said waveguide by heating in the presence of said wetting layer.
Dependencies are inferred from the claim text.