Erbium-doped silica-germania sputtered films: photorefractivity and photoluminescence

We report on the fabrication and spectroscopic characterization of highly photorefractive Er3+/Yb3+ co-activated silica-germania planar waveguides, single mode at 1550 nm, deposited by radio-frequency magnetron-sputtering technique. Details of the sputtering procedure are reported. The structural properties of the waveguides were investigated by Raman spectroscopy. Guiding properties of the films were tested by m-line measurements at different wavelengths, and propagation losses measured at 633nm and 1300nm. The emission of the 4I13/2 ? 4I15/2 transition of the Er3+ ion was observed upon excitation of the TE0 mode at 980 and 514.5 nm. Back energy transfer from Er3+ to Yb3+ was demonstrated by measurement of Yb3+ emission upon Er3+ excitation at 514.5 nm. Photoluminescence excitation spectroscopy was used to obtain information about the Yb3+ to Er3+ energy transfer process.