Erbium diffusion from erbium metal or erbium oxide layers deposited on the surface of various LiNbO3 cuts

In this paper the doping of erbium from thin layers deposited on the LiNbO3 surface with an emphasis on the relations between changes in the LiNbO3 structure and the luminescence properties of Er:LiNbO3 have been studied. The erbium-containing layers were primarily characterised in terms of the luminescence at 1.5 μm. The obtained results showed a high level of structural ordering in the samples after indiffusion of Er at high-temperature. This was apparent from the luminescence results, where more than 6 quite narrow luminescence bands were found, and also from the RBS/channeling analysis which showed, that the doped structure has similar degree of ordering as the bulk crystal LiNbO3. In terms of luminescence intensity at 1.5 μm a better source for the erbium doping seems to be the erbium oxide layer. The highest luminescence intensity values were among the cuts achieved in the Z cut.