Confocal micro-luminescence of Zn-diffused LiNbO3:Tm3+ channel waveguides

Zinc-diffused channel waveguides fabricated in thulium-doped LiNbO3 have been analyzed by means of confocal micro-luminescence techniques. Modifications induced by Zn2+ ions in the doped-crystal substrate are characterized following the evolution of the 3H4→3H6 luminescence of thulium ions at 795 nm, showing the existence of two different regions in the waveguide. Several Raman modes of LiNbO3 have been used as well to study the differences between the waveguide and the bulk material.