Etch variation tolerant directional couplers
AssigneeHewlett Packard Enterprise Development LP
InventorsPENG SUN, MIR ASHKAN SEYEDI, THOMAS VAN VAERENBERGH, MARCO FIORENTINO
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Abstract
Embodiments of the present disclosure provide etch-variation tolerant optical coupling components and processes for making the same. An etch-variation tolerant geometry is determined for at least one waveguide of an optical coupling component (e.g., a directional coupler). The geometry is optimized such that each fabricated instance of an optical component design with the etch-variation tolerant geometry has substantially the same coupling ratio at any etch depth between a shallow etch depth and a deep etch depth.
Claims20
A method comprising:
- determining one or more guided modes of a directional coupler comprising a first waveguide and a second waveguide;
- determining a range of etch depths for the directional coupler from a shallow etch depth to a deep etch depth;
- determining an etch-variation tolerant shape of a coupling portion of the second waveguide in a coupling region between the second waveguide and the first waveguide, the coupling region comprising the coupling portion of the second waveguide parallel to a coupling portion of the first waveguide and separated by an etch gap;
- and
- fabricating the directional coupler comprising the first waveguide and the second waveguide having the determined etch-variation tolerant shape in the coupling region,
- wherein the shape of the second waveguide in the coupling region is configured to control a transverse mode profile of each of the one or more guided modes within the coupling portion of the second waveguide based on an etch depth of the etch gap within the coupling region between the shallow etch depth and the deep etch depth.
A directional coupler comprising:
- a first waveguide disposed on a substrate;
- a second waveguide disposed on the substrate;
- and
- an etch gap between the first waveguide and the second waveguide, the etch gap comprising a coupling region including a coupling portion of the first waveguide and a coupling portion of the second waveguide,
- wherein the coupling portion of the second waveguide comprises an etch-variation tolerant waveguide geometry configured to control a transverse mode profile of one or more guided modes within the coupling portion of the second waveguide based on an etch depth of the etch gap within the coupling region.
An etch-variation tolerant directional coupler comprising:
- a ring waveguide disposed on a substrate having a fixed shape and comprising a ring coupling portion;
- a bus waveguide disposed on the substrate comprising a bus coupling portion;
- an etch gap separating the bus waveguide and the first waveguide;
- a coupling region comprising the bus coupling portion, the ring coupling portion, and an etch coupling portion of the etch gap;
- and
- the etch coupling portion comprising one or more etch depths,
- wherein the bus coupling portion comprises an etch-variation tolerant geometry configured to control a transverse mode shift of a guided mode of light within the bus coupling portion.
Dependencies are inferred from the claim text.