Abstract

The output power required from fiber amplifiers has been increasing over the last few years for a several reasons. First, an increase in the number of WDM channels requires a corresponding increase in the amplifier output power. Second, as amplifier designs have become more complex in order to meet stringent system requirements of low noise figure, flat gain, and insensitivity to input signal variations, many lossy elements, such GFF, power monitoring taps, supervisory channel taps, dispersion compensating modules, dynamic gain equalizers, channel monitors have to be incorporated into the amplifier. To compensate for this added loss and to maintain the required output power, the pump power needs to increase. Figure 1 shows a block diagram of a typical gain-flattened C-band fiber amplifier with mid-stage (MS) access. Currently, WDM amplifiers with output powers up to 23 dBm in the C-and L-band are frequently required, and a need for WDM amplifiers with 25 to 27 dBm output is rapidly increasing. Other applications such as CATV, free space communication systems, component testing, and remote sensing require narrow-band high power amplifiers in the 30–40 dBm range.

© 2002 Optical Society of America