Space radiation effects on erbium-doped fiber devices: sources, amplifiers, and passive measurements

Measurements have been made of the effect of γ-irradiation on the performance of active erbium-doped fiber devices. These include the decrease in optical power of an erbium-doped fiber amplifier (EDFA) and a superluminescent source (SLS), and the shift in centroid wavelength of the SLS with exposure. Calculations have been performed to correlate these effects with the radiation-induced absorption measured passively. Excellent agreement was obtained for the radiation-induced power loss in the EDFA, and good agreement was obtained for the SLS. However, the calculation underestimated the centroid wavelength shift in the SLS by a factor of ~3. A model has been developed to extrapolate the results of passive loss measurements to the low dose rates typical of the natural space environment