Radiation Effects on WDM and DWDM Architectures of Preamplifier and Boost-Amplifier

Abstract

We investigated the X-ray [40 keV, 700 Gy(SiO2), ~80 mGy/s] radiation effects on the performances (gain) of Er-doped fiber preamplifier (EDFA) and Er/Yb codoped fiber boost amplifier (EYDFA). Various EDFA and EYDFA architectures have been designed to operate either in wavelength division multiplexing (WDM) or dense WDM (DWDM) schemes. We compare the performances of amplifiers based on conventional or radiation-hardened (RH) versions of the active Er-doped or Er/Yb-codoped fibers. Our results show that for all amplifier architectures, the various channels undergo similar gain degradation levels and kinetics, as expected from the measured spectral dependence of the radiation-induced attenuation of the phosphosilicate (ErYb-doped) and aluminosilicate (Er-doped) glass matrixes of these fibers. This degradation remains very limited for the amplifiers based on RH fibers, with a gain decrease of less than 0.3 mdB.Gy−1 for the EDFA (~30 dB initial gain) and less than 0.8 mdB.Gy−1 for the EYDFA (~18 dB initial gain) in the DWDM architecture.