Persistent Spectral Hole Burning in Samarium and Aluminum Codoped Silica Films Prepared by RF Sputtering

We observed persistent spectral hole burning in the excitation spectra of a Sm and Al codoped SiO2 thin film at 77 and 180K. The film was prepared from Sm, Al and SiO2 by RF co-sputtering at a substrate temperature of 300°C. At 77K, the width of the hole was 2cm-1 with a depth of 4% of the total intensity, while at 180K, they were measured at 10cm-1 and 1% of the total intensity. The optical absorption and photoluminescence properties of the deposited films were changed by the use of elemental Sm and Al instead of Sm2O3 and Al2O3.