Tunable Optical Beam Deflection Via Liquid Crystal Gradient Refractive Index Generated By Highly Resistive Polymer Film

An effective tunable optical beam deflection device based on a periodic gradient refractive index (GRIN) profile is reported, which is capable of achieving a 5 degrees beam deflection with an angle resolution of 0.5 degrees. The operation voltage is around 6 V-pp, and the maximum operation frequency is 2 kHz. The GRIN beam deflection device is induced by periodically varying liquid crystal orientations. A highly resistive and patterned polymer film with a resistivity of 11 G Omega/sq is deposited to achieve a linear potential distribution between the two addressing electrodes in every unit cell. The resulting electric field pattern across the device is sawtooth-like. Both the device fabrication and the driving interconnection circuit are very simple. The advanced materials and the techniques used in this device are also applicable to other tunable optical and photonic components (such as adaptive lenses and light intensity modulators) by adapting the electrode design and the voltage signals.