Fluorescence properties of erbium-doped germanate glasses

Abstract

Two erbium doped germanate glass samples prepared by sol-gel process and melting and casting method, respectively, have been characterized. A fluorescence lifetime of 2.5 ms at the <SUP>4</SUP>I<SUB>13/2</SUB> level and a very broad bandwidth (FWHM: 53.7 nm) around 1.55 micrometers have been observed for the sol-gel sample. The fluorescence lifetime and the spectrum bandwidth for 1.535 micrometers transition for the sample fabricated by the melting and casting technique were measured to be 10 ms, and 19 nm (FWHM). The cooperative up-conversion coefficient is measured to be 1.3 X 10<SUP>18</SUP> cm<SUP>3</SUP>/s for the sample with an erbium concentration of 2.69 X 10<SUP>20</SUP> ions/cm<SUP>3</SUP>.