Method of laser enhanced thermal diffusion
AssigneeHughes Aircraft Company
InventorBor-Uei Chen
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Abstract
There is disclosed a method by which a three-dimensional horn structure at the end of a channel waveguide in a dielectric chip is produced to facilitate coupling of a fiber optic waveguide by butt coupling techniques. The three-dimensional horn structure is fabricated by localized surface diffusion resulting from superposing a CO.sub.2 laser heating beam on the desired enlarged area while diffusion of the waveguide is taking place or after it has taken place in a controlled ambient furnace atmosphere.
Claims12
A process for forming a channel optical waveguide having a three demensional structure therein comprising the steps of:
- thermally diffusing an optical waveguide into a substrate to form a channel waveguide which is substantially uniform in cross-section throughout a substantial portion of its length;
- and
- raising a selected portion of the channel waveguide to a temperature where further diffusion will take place so that a diffused structure of larger cross section than the substantially uniform channel waveguide is formed at the selected location.
The process for forming a channel optical waveguide having a three dimensional structure therein comprising the steps of:
- thermally diffusing an optical waveguide into a substrate to form a channel waveguide of substantially uniform cross-section through most of its length;
- and
- directing a continuous wave laser onto a selected portion of the channel waveguide to raise the selected portion of the channel waveguide to a temperature where further diffusion takes place at the selected portion of the channel waveguide so that the channel waveguide has a larger cross-section at the selected portion of the channel than the substantially uniform channel waveguide away from the selected location.
A process for forming a channel optical waveguide wherein the waveguide depth and width are independently controlled comprising the steps of:
- thermally diffusing an optical waveguide into a subtrate to form a channel waveguide;
- additionally heating a selected portion of the channel waveguide to a temperature where further diffusion takes place to form a horn structure portion of optical waveguide to greater depth than the substantially uniform channel waveguide formed away from the selected location.
Dependencies are inferred from the claim text.