HIGH ALIGNMENT TOLERANCE EDGE COUPLER

An edge coupler has a wide end, a narrow end, and a tapering thickness. The narrow end is coupled to a waveguide in a photonic integrated circuit (PIC). The wide end is coupled to an optical transmitter or receiver. The edge coupler thickens by tapering downward into the buried oxide layer of a BOX substrate. An upper surface of the edge coupler may be planar. A pedestal may be formed in the oxide layer so that a laser diode mounted on the pedestal will be vertically aligned to the edge coupler. Alternatively, the pedestal may be formed in a substrate under the oxide layer so that the core of an optical fiber mounted on the pedestal will be vertically aligned to the edge coupler. The pedestal may be in a cavity that facilitates horizontal alignment between the laser diode, optical fiber, or other such device and the edge coupler.