Optical properties of Yb3+- doped phosphate laser glasses

Ytterbium-doped phosphate glasses have been prepared and studied their spectroscopic properties through absorption, emission and Fourier transform infrared (FTIR) spectral studies and time-resolved luminescence decay curves. The absorption cross-section has been found to vary with the variation of Yb2O3 concentration. The results of the FTIR spectra show that the OH- content is increasing with increase of the Yb2O3 concentration in these glasses. The decay curves of the F-2(5/2) level of Yb3+ ions exhibit a single exponential nature for all the concentrations. The lifetimes of the F-2(5/2) level of Yb3+ ions decreases from 1.04 to 0.27 ms when the Yb2O3 concentration is increased from 0.1 to 6.0 mol%. The quenching of lifetimes has been found to vary directly with the inter-ionic distance between the Yb3+ ions. The concentration quenching of the lifetime has been analyzed using different energy transfer processes and no evidence of cooperative luminescence of Yb3+ ions has been found in these glasses, which reveals that the present glasses are useful for photonic device applications. The laser performance properties have also been evaluated for these glasses and compared with those of other reported Yb3+-doped glass systems. (C) 2011 Elsevier B.V. All rights reserved.