Abstract
We review core-pumped and cladding-pumped multicore erbium-doped fiber amplification (EDFA) technology
and discuss the configuration of the connections between multicore transmission fibers and multicore
EDFAs. The core-pumped one contributes to downsizing per core since the case size is identical as
that of the conventional EDFAs. The size of the optical devices using multicore fibers achieved the same
size as those using single-core fibers. The cladding-pumped one reduced the power consumption. Lower
power consumption for a core than that of the conventional EDFAs was achieved by a C-band cladding-
pumped coupled 12-core EDFA. We reviewed techniques that increase cladding pump efficiency.
The configuration of the connections depends on the directions of the optical signals on a multicore fiber.
Co-directional and bi-directional propagation are respectively supported by low loss splicing of the multicore
fibers and low insertion loss of fan-in fan-out devices.
