Space qualification of multi-channel optical fiber amplifier for low Earth orbit satellite-to-ground direct downlinks

We present the space qualification of a multi-channel mid-power booster optical fiber amplifier (OFA) suitable for 1550nm LEO satellite to ground laser communication downlinks. The end-to-end OFA development from conceptual design all the way through qualification testing followed ECSS-level Product Assurance guidelines for deployed materials, components and processes. The environmental qualification test programme relied on ECSS-E-10-03C which is the ESA standard for qualification testing of space segment hardware. The qualification results show robust functional and structural performance following stress at all 3 possible excitation axes with high level sine vibration, random vibration and mechanical shock as well as thermal cycling between survival and operating temperatures in vacuum condition. In addition to thermo-mechanical tests, proton and gamma radiation tests performed on component and sub-assembly level suggest that the OFA is capable to deliver its performance under ionizing and non-ionizing radiation levels found in the LEO orbit. The OFA has been delivered for system integration into the Optel-mu terminal, applicable to small satellite platforms.