The power consumption of the laser systems is an important aspect of optical satellite communication technology. We present an optical amplifier for a WDM optical communication system with a simultaneous multichannel amplification in a single fiber in the 1 μm wavelength range. The desired enhanced wall-plug efficiency of ∼30\% can only be achieved through fiber technology. Combining the experiences of in-house manufactured optical fiber components and of laser developments for space applications, an all-fiber amplifier solution was designed. Each of the 10 channels can be efficiently amplified up to a total power level of 100W.