TiO2, LiNb3O8, and (TixNb1−x)O2 compound kinetics during Ti:LiNbO3 waveguide fabrication in the presence of water vapors

The presence of water vapor in the annealing atmosphere during Ti:LiNbO3 optical waveguide fabrication prevents Li out-diffusion, inhibits LiNb3O8 growth, and furthermore decomposes this phase if already formed. As a consequence, the TiO2 and the mixed oxide (TixNb1−x)O2 growth kinetics change. A proton in-diffusion in LiNbO3 with OH− defects and (Li1−yHy)NbO3 molecule formation is suggested to explain these effects and to account for the detected increase of absorbance at 3480 cm−1.