Demonstration of C+L 8.7-THz 7-core multicore EDFA with a single pump laser diode using pump recycling technology

An L-band 4.1-THz 7-core signal has been successfully amplified by using recycled pump light from C-band 4.6-THz 7-core cladding-pumped multicore EDFA. 4.8 % of power conversion efficiency with a single pump laser diode for C+L-band cladding-pumping was obtained twice large as for C-band.