Abstract

Automatic-level control (ALC) of an amplifier output power is very important for preserving the level-diagram necessary for optical transmission system design. The ALC scheme of controlling pump power is desirable for simplicity and low power consumption. But noise figure deterioration should be considered when pump power is reduced. The noise figure is especially important when many amplifiers are cascaded. However, amplification characteristics which include the noise figure during ALC operation have not been researched in detail. In this paper, we report amplification characteristics of Er-doped fiber optical amplifiers during ALC operation and propose a novel configuration for wide input-power range with low noise.

© 1992 Optical Society of America