Beam Pointing Precision Control by Using a Liquid Crystal Optical Phased Array

For laser beam steering, a pure optical-electric system without mechanical or inertial parts is used. The new device is a Liquid Crystal Optical Phased Array (LCOPA). Supplying electric field to liquid crystal cell with electrodes, the extraordinary refractive index changes, which results in phase shift that modulates the direction of incident beam. The advantages of this device are small size, less energy consuming, programmable and addressable control. A one dimensional device is designed and tested. The resolution of the steering angle is 20 mu rad, the range is +/- 2 degrees. The effect of flyback region and phase valley on diffraction efficiency is also discussed briefly.