Radiation effects on the gain of thulium doped fiber amplifier: Experiment and modeling

• Effect of ionizing radiation doses to the TDFA coil has been studied.
• A theoretical model is used to predict the gain of TDFA after irradiation.
• The gain is deteriorated by the neutron doses.

The optical elements which are placed in orbits around the earth can experience harsh radiation environments that originate from trapped-particle belts, cosmic rays and solar events. Therefore, it is crucial to study the effect of those events on the fiber amplifier devices. In the present paper, the thulium doped fiber amplifier (TDFA) has been irradiated by a neutron beam of different doses for various exposure times from an Am-241/Be-9 neutron source. The gain of the TDFA has been calculated theoretically and recorded after and before irradiation. The calculated results by the proposed model are in good agreement with the experimental ones. It indicates that the gain of TDFA deteriorates after being irradiated by a neutron dose. The gain of irradiated TDFA reduced to 17.1 dB at a dose of 720 Gy.