US Patent 9140850 Optical coupling structure and optical fiber amplifier

An optical coupling structure optically coupling a plurality of core portions and a plurality of core portions includes a plurality of first core portions outputting a plurality of lights, a first lens focusing or collimating the plurality of lights outputted from the plurality of first core portions, a second lens focusing the plurality of lights focused or collimated by the first lens, a plurality of second core portions, the plurality of lights focused by the second lens being inputted into the second core portions respectively, and an optical functional component disposed between the first lens and the second lens, the plurality of lights being inputted into the optical functional component. At least one of the first lens and the second lens is configured by a lens or a lens group focusing or collimating the plurality of lights collectively.