Fast, reconfigurable light-induced waveguides

Fast and reconfigurable one-dimensional waveguides are produced by interban d photorefraction. The index barriers are induced by ultraviolet light. The guiding of a red laser beam with a full width at half-maximum of 15 mu m i s demonstrated. Buildup and decay times of the waveguide in pure KNbO3 are of the order of 100 mu S and 10 ms, respectively. The intensity of the guid ed light has no influence on the guiding properties over the range from 4 m W/cm(2) to 200 W/cm(2). By reconfiguration of the waveguide, deflection ang les of as much as 1.75 deg inside the crystal are achieved. (C) 1999 Optica l Society of America OCIS codes: 190.5330, 230.7370.