COMPARISON OF THE SPECTRAL AND TEMPERATURE DEPENDENCES OF THE HOMOGENEOUS LINEWIDTHS IN EU-3+-DOPED FLUORIDE AND OXIDE GLASSES

Laser-induced fluorescence line narrowing was used to measure the homogeneous linewidth of the **5D//0-**7F//0 transition of Eu**3** plus in a lithium silicate oxide glass and ZBLA fluoride glass. The linewidths were determined as a function of temperature and spectral position within the inhomogeneous line profile. In general, the homogeneous linewidth increases as T**2 in the temperature range between 10 and 160 K for both types of glass with the magnitude of the linewidth in the fluoride glass being approximately an order of magnitude smaller than in the oxide glass. The recently developed model of line broadening by Raman scattering of fractons is used to interpret the data. In addition, the variation in homogeneous linewidth with spectral position is observed to have an inflection in the region of structure in the profile of the inhomogeneous band.