Apparatus for deflecting light beam

摘要

An optical deflector including a waveguide which has an electrooptic effect and which is adapted to guide rays of light therethrough. The deflector comprises a deflector portion having deflection electrodes disposed on a portion of the waveguide and spaced apart in a selected direction intersecting a direction of propagation of the light. The deflector further comprises a controller for applying deflection voltages to the deflection electrodes to establish a distribution of refractive index of the above-indicated portion of the waveguide in the above selected direction. The controller periodically changes the deflection voltages to vary the refractive index distribution, thereby deflecting the light passing through the waveguide. The waveguide may be formed on a surface of a substrate made of an electrooptic material. The substrate may have a converging portion including convergence electrodes disposed on another portion of the waveguide, to converge the rays of light deflected by the deflector portion, convergence voltages to be applied to the convergence electrodes being varied according to an angle of deflection of the rays, to permit the convergence of the rays on a surface of an object irrespective of the deflection angle.