CC BY 4.0Lezius, MatthiasMatthiasLeziusPenka, DanielaDanielaPenkaMelin, GillesGillesMelinRobin, ThierryThierryRobinCadier, BenoitBenoitCadierKuhnhenn, JochenJochenKuhnhennWeinand, UdoUdoWeinandHolzwarth, RonaldRonaldHolzwarth2024-04-172024-04-172023https://publica.fraunhofer.de/handle/publica/466139https://doi.org/10.24406/publica-295410.1117/12.268994710.24406/publica-2954A radiation tolerant Erbium fiber based optical frequency comb has been developed and environmentally tested. The system remained operable after an accumulated dose of 1 kGy. The underlying femtosecond fiber oscillator and Erbium fiber amplifiers have been manufactured from speciality doped fibers. The fiber optic system has been assembled and packaged using low outgassing components in a flight representative package before it was irradiated under active operation in two stages a 500 kGy. The accelerated ageing with dose rates of 10 mGy/s in water was tested using the calibrated Cobalt 60 source of the ESA-ESTEC facilities. The comb laser remained fully functional while the oscillator lost up to 30% of output power after the full exposure to the accumulated dose of 1 kGy. The fiber amplifiers lost 5-7% of output power.enfrequency combradiation harderbium doped fiber laserconference paper