Fast, reconfigurable light-induced waveguides

Fast and reconfigurable one-dimensional waveguides are produced by interband 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 mum is demonstrated. Buildup and decay times of the waveguide in pure KNbO(3) are of the order of 100 mus and 10 ms, respectively. The intensity of the guided light has no influence on the guiding properties over the range from 4 mW/cm(2) to 200 W/cm(2) . By reconfiguration of the waveguide, deflection angles of as much as 1.75 deg inside the crystal are achieved.