A piezo-electric actuator is rigidly mounted for a portion of one surface and provided with opposing electrodes for application of a bias. Because the mounted portion is constrained from deformation, the piezo-electric actuator deforms in a bending manner upon application of a bias. The actuator is provided with a mirror surface for selective reflection of an incident light beam in accordance with a bending deformation of the actuator. The actuator can also modulate a light beam by selectably deflecting into the light path to thereby block the light beam.