Research Progress on Beam Scanning Based on Liquid Crystal Optical Phased Array

The acquisition, pointing, and tracking (APT) technology is important to establish the reliable links in space laser communication. The conventional APT technology employs a mechanical rotation method to achieve steering control. In addition, the conventional APT technology exhibits some significant disadvantages, including large volume and rotational incrtia as well as high power consumption. Further, the classical APT technology cannot satisfy the practical requirements of space laser communication, i.e., light weight, miniaturization, and low power consumption. Therefore, to study the non-mechanical beam scanning technology is of considerable significance. When compared with the conventional APT technology, an optical phased array is a promising non-mechanical beam scanning technique because it provides various advantages, including high scanning accuracy, random deflection, and strong stability. The liquid crystal optical phased array (LCOPA) is observed to develop rapidly. In this study, we briefly introduce the basic principle of an optical phased array for beam scanning. Subsequently, we review the status of current research about LCOPAs. Further, three key performance indicators, i.e., response time, deflection efficiency, and deflection accuracy, as well as the influence factors arc analyzed. In addition, the methods used to improve the LCOPA performances arc also summarized.