We present the results of our work conducted in the context of ESA’s ARTES ScyLight framework programme (SeCure and Laser Communication Technology). For the associated HydRON project (High thRoughput Optical Network), a prototype model of a fiber-based high-efficiency laser amplifier system (HELA) operating in the 1 µm wavelength range has been developed up to a technology readiness level (TRL) of 4. The laser system is intended to be employed for coherent optical communication with wavelength division multiplexing (WDM) in future high-bandwidth satellite communication networks. Combining the experience of in-house manufactured fiber components and laser systems, an all-fiber amplifier solution was designed to realize an enhanced electrical-to-optical wall-plug efficiency of around 30\%. The HELA system simultaneously amplifies the 10 input channels provided by a self-designed WDM seed source, with input powers ranging from 1 to 10 mW per channel, to a total optical output power of 100 W. Here, the WDM approach combined with a single-mode, high average output power signal shall enable the realization of optical interconnections with up to Terabit per second data rates over large distances between satellites and with their corresponding ground stations.