DETERMINATION OF SPECTRAL LINEWIDTHS BY VOIGT PROFILES IN YB3-DOPED FLUOROZIRCONATE GLASSES()

Homogeneous and inhomogeneous spectral linewidths of the (F-2(5/2))(1) - (F-2(7/2))(1) transition in Yb3+-doped fluorozirconate glasses are determined by fitting Voigt profiles to the inhomogeneously broadened emission and absorption spectra between 10 and 300 K. The homogeneous linewidth varied as (12 +/- 2) chi T(1.9 +/- 0.1) MHz for emission and (10 +/- 1) chi T1.9 +/- 0.1 for absorption over the entire temperatur e range, similar to that of other rare-earth-doped systems previously studied by fluorescence line narrowing and photon echoes. The inhomoge neous linewidths were nearly independent of temperature, but different by similar to 30% between emission and absorption. The structural and dynamic properties in this disordered system an discussed.