Electooptic Fresnel lens-scanner with an array of channel waveguides

A new type of beam scanner is discussed based on a 1-D Fresnel zone plate consisting of titanium-diffused channel waveguides on LiNbO3. By electrooptically controlling the guided-wave phase, both beam scanning and 1-D focusing are achieved without a condensing lens. It was experimentally confirmed using the scanner with twenty-one Fresnel zones that the beam spot with a diameter of approximately 50 microm at half-power level of diffraction pattern is scanned over a distance of +/-70 microm in the focal plane with an applied voltage of +/-40 V at 633 nm.