Absorption and emission cross sections of Er3+ in Al2O3 slab waveguides
Appl. Opt. , Volume 36 p. 3338- 3341
Al2O3 slab waveguide films were doped with erbium using ion implantation to a peak concentration of 1.5 at. %. Prism coupling measurements show absorption caused by 4I15/2 → 4I13/2 intra-4f transitions in Er3+ with a maximum at 1.530 µm of 8 dB/cm. The Er3+ absorption cross section is determined as a function of wavelength. We used the McCumber theory to derive the emission cross section spectrum from the absorption results, which we then compared with the Er3+ photoluminescence spectrum. The peak absorption and emission cross sections are found to be 6 x 1021cm-2. The results are used to predict the optical gain performance of an Er-doped Al2O3 optical amplifier that operates around 1.5 µm.