Er3+/Yb3+-codoped silica-germania sputtered films : structural and spectroscopic characterization

Abstract We report on the fabrication and spectroscopic characterization of highly photo-refractive Er 3+ /Yb 3+ coactivated silica–germania slab 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 films were investigated by Raman spectroscopy. Propagation losses of guided modes were measured at 633 nm and 1320 nm. The emission of the 4 I 13/2  →  4 I 15/2 transition of the Er 3+ ion was analyzed upon excitation of the TE 0 mode at 514 and 981 nm. Back energy transfer from Er 3+ to Yb 3+ was observed by measurement of Yb 3+ emission upon Er 3+ excitation at 514.5 nm. Photoluminescence excitation spectroscopy was used to obtain information about the Yb 3+ to Er 3+ energy transfer process.