Erbium-doped multi-element fiber amplifiers for space-division multiplexing operations

Erbium-doped multi-element fiber (MEF) amplifiers have been fabricated to simultaneously amplify multiple transmission channels. MEF devices comprise of multiple single-core fibers (elements) combined in a common coating, with each element working as a single fiber in isolation. MEFs containing 3-elements and 7-elements have been fabricated and characterized. Each element of the fabricated MEFs provides nearly 32 dB of gain with a noise figure of <5  dB for an input signal level of −23  dBm at 1530 nm. Different permutations of element pairs within the MEFs were checked for crosstalk and none was detected, confirming the simultaneous multi-channel amplification capabilities of MEFs.