Transient and persistent spectral hole burning in Eu3+-doped sol–gel produced SiO2 glass

Transient and persistent spectral hole burning (TSHB and PSHB) experiments were performed on Eu3+ ions in sol–gel SiO2 glasses with aluminum co-doping. Differences in the hole burning behavior were observed among samples made from two organosilicate precursors that were annealed to a series of final temperatures. All glasses exhibited persistent spectral holes when annealed to 800°C but, as the annealing temperature was raised to 1000°C, an increasing number of Eu3+ ions exhibited TSHB with a corresponding decrease in the number of ions showing PSHB behavior. The transient hole burning behavior is similar in nature to that observed for Eu3+-doped silicate melt glass.