Radiation-resistant cerium co-doped erbium-doped fibers for C- and L-band amplifiers in a high-dose gamma-radiation...

We experimentally demonstrate a comparative study on the radiation-resistant cerium (Ce) co-doped erbium-doped fiber amplifiers (EDFAs) exposed to a high-dose gamma-radiation environment of 1.8 kGy/h dose rate in the C and L bands. Our results show that Ce is an effective co-dopant in the aluminosilicate EDFs for suppressing radiation-induced attenuation (RIA) of more than an order of magnitude lower than the Ce-free EDF. After exposure to a high-dose gamma-radiation of up to 10 kGy, the Ce co-doped EDF still exhibits good radiation tolerance, providing 41.6 ± 2.9 dB gain and 5 ± 0.8 dB NF from 1535-1560 nm for a -25 dBm input signal. In the L-band, we report, for the first time, the radiation-resistant EDFA with the radiation-induced gain degradation (RIGD) of 3.7 dB under 2.5 kGy irradiation and 4.4 dB under 10 kGy irradiation at 1600 nm. Also, the radiation-dependent gain coefficient and gain saturation were studied in the C and L bands. A comparison of different Ce co-doped EDFs exposed to different total gamma doses reveals the radiation impact on the amplifier performance, indicating the feasibility of using Ce co-doped EDFs for space-based optical communications, requiring robust radiation stability.