Spectroscopic study of Nd3+ doped PZG fluoride glass planar waveguides

The optical properties of Nd3+ doped PZG (PbF2-ZnF2-GaF3) fluoride glass planar waveguides elaborated by physical vapour deposition (PVD) on CaF2 substrates have been analysed in comparison with those of the bulk material. The infrared (IR) side luminescence evidences similar properties for the films and the bulk, while reabsorption and saturation effects alter the guided output luminescence in highly doped waveguides. The IR luminescence decays show deviations from the bulk behaviour which have been related to the inhomogeneous composition of the films pointed out by the gradient refractive index profile. The analysis by waveguide Raman spectroscopy does not reveal significant differences between the film and the bulk materials. Finally, an intense visible upconversion luminescence is also observed in highly doped waveguides. (C) 1998 Elsevier Science B.V.