Undesirable contaminants possibly introduced in LiNbO3 electro-optic devices

Inorganic contaminants in the fabrication of LiNbO3 optical waveguide devic es are examined with regard to their effect on the ultimate device performa nce and quality. We find a possibility that some chemicals such as a photor esist developer, etc., leave contaminants including silicon and alkalis on the LiNbO3 wafer, and result in an increase of light propagation loss, a pe aling of the SiO2 layer from the wafer, and a large dc drift. (C) 1999 Amer ican Institute of Physics. [S0021-8979(99)08023-8].