A first photonic die has a first coupling edge and a first die surface, and comprises: a first waveguide extending in proximity to the first coupling edge; a portion of the first die surface forming an alignment edge substantially parallel to the first waveguide; and a first alignment feature etched into or formed adjacent to the first coupling edge. A second photonic die has a second coupling edge and a second die surface, and comprises: a second waveguide extending in proximity to the second coupling edge; a portion of the second die surface configured to form a receptacle sized to constrain a position of the alignment edge; and a second alignment feature etched into or formed adjacent to the second coupling edge and configured to enable alignment with the first alignment feature when the first photonic die and the second photonic die are substantially aligned with each other.