Spectral dependence of the excited-state absorption of erbium in silica fiber within the 1.48–1.59μm range

We report the study of the excited-state absorption (ESA) spectrum of Er3+ in erbium-doped silica fiber (EF) within the telecom band, 1.48–1.59μm. Two experimental techniques, the detection of up-conversion emission following the ESA process and the measurement of the EF nonlinear transmission coefficient, both supplied with a theoretical background, allow obtaining a mutually consistent spectral behavior of the ESA parameter, which is the ratio of ESA to ground-state absorption cross section, at 1.48–1.59μm excitation.