Two-stage L-band EDFA with gain-clamped characteristics using partial gain-clamping

Abstract

We theoretically and experimentally investigate the static and dynamic properties of two-stage L-band erbium-doped fiber amplifiers (EDFAs) that are partially gain-clamped. Partial (all-optical) gain-clamping is obtained by forming a fiber grating laser in either the first or the second stage of the two-stage EDFA. Although the amplifiers are only partially gain-clamped, results show that they exhibit good gain-clamped characteristics. Furthermore, the amplifier configuration in which the second stage is gain-clamped can have a very low noise figure and a small transient gain (power) excursion.