20-GHz soliton amplification and transmission with an Er^3+-doped fiber

A 20-GHz soliton burst pulse train at 1.552 microm is successfully amplified with a 3.5-m Er(3+)-doped fiber amplifier. It is possible to transmit 20-GHz solitons with an N = 1 soliton power of 10 mW and a pulse width of 10 psec. The Er(3+)-doped fiber has a doping concentration of 1370 parts in 10(6) and is pumped by InGaAsP laser diodes. The gain of the fiber is determined by the average input power because of the slow gain recovery time.