Time-resolved spectroscopy of Sm3+ in silica and silica-Al sol-gel glasses

The fluorescence of trivalent samarium in silica glasses and silica aluminu m glasses prepared by the sol gel method was studied by time resolved spect roscopy. For short time excitations mostly fluorescence from the host matri x was observed. The samarium fluorescence could be clearly seen after a lon ger time delay. The ratio of the intensity of the electric dipole transitio n to that of the magnetic dipole decreased with the time elapse after the e xcitation, as predicted by the theory of transition probabilities. (C) 1999 Elsevier Science B.V. All rights reserved.