Formation of waveguide channels by dark spatial solitons in a planar waveguide optically induced in a lithium niobate crystal

The formation of optical waveguide channels is experimentally demonstrated upon the photorefractive self-action of a phased light beam in a planar waveguide optically induced in an iron-doped lithium niobate crystal. Planar and channel waveguides were produced by using a 633-nm He—Ne laser with output powers 1 mW and ∼10 μW, respectively.