Patent ID: 9726821
Date: 2017-08-08
CPC Classifications: G02B

Claim:
1. A device comprising: a substrate having an edge; a first waveguide on the substrate, the first waveguide comprising a constant-width region and a tapered region terminating at the edge of the substrate, the tapered region having a smaller width at the edge than at the constant-width region; and, a pair of second waveguides on the substrate, and located on either side of the tapered region of the first waveguide, each of the pair of the second waveguides terminating at the edge at a first end and extending to a second end adjacent the constant-width region of the first waveguide, the second end distal the first end; at least a portion of each of the pair of second waveguides being tapered, and optically coupled to the first waveguide to transition a mode of an optical signal in the first waveguide from an elliptical mode at the edge towards a confined mode in the first waveguide in the constant-width region, each of the pair of second waveguides having a larger width at the edge than adjacent an interface between the constant-width region and the tapered region of the first waveguide.