Efficiency Optimization of a tunable, non-mechanical beam steering device based on fringe field switching and Pancharatnam phase

There has been an increasing demand for fast and efficient random access pointing within emerging applications such as LiDAR. space based optical communications, displays. and autonomous vehicles. Particularly. Electro-Optical beam steering approaches have been considered to replace current mechanical beam steerers which are dominant technology in these applications. However. mechanical approaches have some issues such as mechanical complexity, pointing stability, high cost, bulky and heavy. Therefore, them is a need to replace mechanical steering devices with less costly nonmechanically scanned ones. Liquid Crystal-based devices are among the top candidates with promising performance. Last year, we have introduced a novel concept to design a tunable liquid crystal beam steering device using dual fringe-field switching (FFS) cell to create an in-plane electric field with local control ability on the director of the liquid crystal [1]. The architecture allows to form a Pancharatnam Phase shape with continuous phase across an aperture without any resets. In this article, we will review optimization process of such a device to provide maximum output efficiency. Step by step optimization of design factors as well as material factors are explained, and an efficiency table is represented for comparison. Finally, sample experimental data is shown to match the modeling expectations for high efficiency.