Fixing the photorefractive soliton

We report the formation of permanent two-dimensional 12-mu m waveguides in a bulk strontium barium niobate crystal. The waveguides are made by formati on of a photorefractive spatial soliton in which the space-charge field ind uces ferroelectric domains that are permanently polarized opposite to the c rystal c axis. The fixed waveguide propagates light with 80% efficiency. Th ese results make possible the permanent recording of intricate optical circ uitry in the volume of a bulk crystal. (C) 1999 Optical Society of America.