Large area liquid crystal beam deflector with wide steering angle
Slim beam deflector that satisfies both a large steering angle and a large area can be very useful in various applications. However, smaller electrode pitch for a large steering angle and enlarge its area are trade-off relation due to the limited number of control channels in electrically tunable beam deflector system. For a large steering angle in the active area where actual diffraction occurs, an indium tin oxide electrode of 2 ？m pitch was implemented through a stepper lithography. The via-hole process was developed to expand the reduced active area due to the small electrode pitch. We developed a beam deflector with 7200 controllable channels in an active area of 14.4 mm Χ 14.4 mm. The maximum deflection angle is 7.643° at a wavelength of 532 nm.