US Patent 10527796 Photonic input/output coupler alignment

Optical alignment of an optical connector to input/output couplers of a photonic integrated circuit can be achieved by first actively aligning the optical connector successively to two loopback alignment features formed in the photonic chip of the PIC, optically unconnected to the PIC, and then moving the optical connector, based on precise knowledge of the positions of the loopback alignment features relative to the input/output couplers of the PIC, to a position aligned with the input/output couplers of the PIC and locking it in place.