Patent 10416381 was granted and assigned to Acacia Communications on September, 2019 by the United States Patent and Trademark Office.
A facet optical coupler, and techniques for forming a facet optical coupler, that includes a waveguide disposed in a trench of a substrate are described. The substrate may be a silicon substrate in some embodiments. A cladding material is first disposed in the trench, and the waveguide is disposed on the cladding material in the trench.