A monolithically integrated, self-aligning, optical-fiber ferrule for a pigtailed opto-electronic module. The ferrule includes a body, a cavity defined within the body, a lateral alignment structure, and an optical-fiber stop. The cavity is to accept and align an optical fiber with an end of the cavity to face an optical aperture of an opto-electronic component. The lateral alignment structure is to self-align laterally the optical fiber with the optical aperture. The optical-fiber stop is coupled to the body, to self-align vertically the optical fiber. The body, the cavity, the lateral alignment structure and the optical-fiber stop are integrated together as a portion of a monolithically integrated chip. A system and a pigtailed opto-electronic engine that include the ferrule are also provided.