Multicore optical fiber connector adapters

A multicore optical fiber connector adapter comprising:

• at least one multicore optical fiber stub comprising:
• a plurality of optical cores, each optical core having an inner core and an outer core;
• a fiber coupling section having a first diameter, wherein the plurality of optical cores has a first pitch at the fiber coupling section;
• a multicore fiber coupling section having a second diameter that is less than the first diameter, wherein the plurality of optical cores has a second pitch at the multicore fiber coupling section that is less than the first pitch;
• and
• a taper section between the fiber coupling section and the multicore fiber coupling section;
• at least one multicore ferrule comprising a first passageway, wherein at least a portion of the multicore fiber coupling section is disposed within the first passageway;
• at least one fiber coupling ferrule comprising a second passageway, wherein at least a portion of the fiber coupling section is disposed within the second passageway;
• a ferrule holder comprising a first end and a second end, wherein the at least one multicore ferrule is disposed in the ferrule holder at the first end and the at least one fiber coupling ferrule is disposed within the ferrule holder at the second end;
• and
• a connector body, wherein the at least one multicore ferrule, the at least one fiber coupling ferrule, and the ferrule holder are disposed within the connector body.