Abstract
The Er-doped fiber amplifier allows direct optical amplification with high pump to signal optical conversion efficiency. The amplifier for a 1.551.tm optical signal is compactly composed of an Er-doped fiber and other optical components. Amplification properties of the amplifier are mainly dependent on the Er doping concentration, the co-dopant, the fiber length, and the performance of the pumping power source. An optimized fiber, for use within the optical amplifier, has a gain of 40dB and a conversion efficiency of 85% from the incident pumping power to the amplified signal power. Amplification properties also depend on the characteristics of the optical signals. This paper explains techniques of structuring high-power Er-doped fiber amplifiers and recent high-power amplifiers.
