A liquid crystal stackable phased array to achieve fast and precise nonmechanical laser beam deflection

In this study, a novel liquid crystal (LC) stackable optical phased array (SOPA) for fine tracking with fast and precise beam steering is proposed. The SOPA was composed of multiple layers of sliced phase shifters (SPSs). Each SPS had two parts for loading different voltages to form programmable phase steps. All LC materials were compatible with this architecture, including blue-phase, polymer network, and ferroelectric LCs. To verify and evaluate the properties of this SOPA scheme, a three-layered SOPA prototype was designed and fabricated according to the standard processing of LC devices. A couple of steering experiments, with steering angles ranging from -100 to 100 μ rad in a step of 10 μ rad, were performed. The steering efficiency recorded in all the experiments exceeded 90%. All the measured switching time of angle-to-angle were less than 10 ms. Herein, the fastest switching time reported was only 1.52 ms.