Multifiber connector for concentric mutli-core fiber

An optical device, comprising:

• a first fiber having a first end and at least a first core and a second core, the at least a first core and a second core being concentric;
• a second fiber having a second end and at least a first core;
• a third fiber having a third end and at least a first core;
• an optical add/drop unit comprising at least one diffractive optical element, the optical add/drop unit being disposed to receive light from the first end of the first fiber and to direct light from one of the first core and the second core of the first fiber into the first core of the second fiber and light from the other of the first core and second core of the first fiber into the first core of the third fiber.

An optical device, comprising:

• a first fiber comprising at least an inner concentric core and an outer concentric core, the inner concentric core of the first fiber being closer to an axis of the first fiber than the outer concentric core of the first fiber, the first fiber having a first end;
• a second fiber comprising at least an inner concentric core and an outer concentric core, the inner concentric core of the second fiber being closer to an axis of the second fiber than the outer concentric core of the second fiber, the second fiber having a second end;
• and
• an optical coupling unit disposed between the first end of the first fiber and the second end of the second fiber, the optical coupling unit;
• wherein light from the inner concentric core of the first fiber is directed by the optical coupling unit to the outer concentric core of the second fiber, and light from the outer concentric core of the first fiber is directed by the optical coupling unit to the inner concentric core of the second fiber.