Electrical fixing of waveguide channels using dynamic self-focusing in strontium-barium niobate crystals

Summary form only given. We investigate the electrical fixing of one- and two-dimensional waveguides in both bulk samples and planar waveguides of strontium-barium niobate (SBN60). Planar waveguides are fabricated by He/sup +/ implantation, resulting in an about 5 /spl mu/m-thin waveguiding layer. Electrical fixing of waveguide channels is achieved as follows. Firstly, all crystals are homogeneously polarized by applying an electric field along the c-axis. After this, the samples are illuminated with focused extraordinarily polarized light (514.5 nm) propagating perpendicular to the c-axis. A typical diameter of the focused beam on the input face is 10 /spl mu/m. Thus the beam diffracts strongly during propagation through the sample. Either a one-dimensionally focused beam (for fixing planar waveguides in bulk samples) or a two-dimensionally focused beam (for fixing channel waveguides in bulk or waveguide samples, respectively) is used. At the same time, the whole crystal is illuminated by an ordinarily polarized background beam from the top. The intensity ratio of focused and background beam is about 100.