J. Fick et al., Fabrication of erbium-doped channel waveguides by a combination of ion exchange and sol-gel techniques, J SOL-GEL S, 19(1-3), 2000, pp. 573-576
Erbium-doped germano-silicate thin films of good optical quality were produ
ced by the sol-gel technique. High refractive index changes of up to 0.018
were obtained by sodium-silver ion exchange. Monomode optical waveguides wi
th Gaussian mode profile were fabricated by this technique. It is shown tha
t, if the ion exchange process parameters are well chosen, the influence of
the waveguide fabrication on the active properties of the material is negl
igible.