Absorption-emission cross-section ratio for Er 3+ doped fibers at 1.5 µm

Erbium doped optical fiber have been demonstrated to be both efficient and practical optical amplifiers in the l.5-μm region.1 Research is now concentrated on optimizing the performance of such amplifiera. Accurate modeling allows possible routes to optimization to be readily evaluated. The ratio of absorption cross section σA to that for emission σE, both at the gain peak and across the band, is crucial to such a model, particularly for in-band (e,g., 1490-nm) pumping.