Abstract

Erbium-doped fiber amplifiers (EDFA) operating at 1.55 μm have been commercially available since 1990. Most EDFAs use high-power semiconductor laser diodes as their pump source, either at the absorption band at 980 nm (strained GaInAs/GaAs quantum well) or at 1480 nm (strained GaInAsP/InP quantum well). The subject of an ongoing debate is which pump laser diode technology is better suited for the different applications. EDFAs pumped at 980 nm have an intrinsically lower noise figure, require a lower pump current and show reduced gain peaking compared to their 1480 nm counterparts. 1480 nm pump laser diodes, on the other hand, have received much attention owing to the excellent reliability of related low-power 1550 nm laser diodes.

© 1995 Optical Society of America