Study and control of the DC drift origins in LiNbO3 electro-optic integrated devices

Our study is aimed to achieve electro-optic modulators with an enhanced stability even at long time. For this we focused our attention on the non-uniformities in the dielectric permittivity and electrical conductivity which appear in the various successive layers which constitute the optical device. We thus show that polaron luminescence and Raman spectroscopy can be efficiently used to control the uniformity of the electrical conductivity of the wafer prior to the fabrication, and then the Li-out-diffusion and Ti-in-diffusion during the process of the waveguide fabrication.