Spectroscopy of Er and Er-Yb-doped phosphate glasses

Optical absorption and emission properties of Er and Er-Yb-doped phosphate glasses are investigated both at low and room temperature in the near infrared spectral region between 800 and 2000 nm, and the results are thoroughly discussed in connection with the expected transitions originating from the crystal-field split I-4(15/2) and I-4(13/2) levels of the Er3- ion. Accurate measurements of the I-4(13/2) fluorescence lifetimes and the determination of the stimulated emission cross section for the Er transition at 1.5 mu m are also reported. Excited state absorption (ESA) from the metastable I-4(13/2) level towards the higher energy levels is measured in the 450-1200 nm spectral region. The ESA absorption peaks are in good agreement with the positions of the higher states of the 4f(11) Er3+ manifold. (C) 2000 Elsevier Science B.V.. All rights reserved.