This article discusses the basic structure and physical characteristics of liquid crystal and gives a description about the application and research status of liquid crystal technology in the field of optical communications. It studies mainly on several practical applications of liquid crystal optical component, simulation technique of turbulent atmosphere and the Space Light-beam Modulator (SLM) in the satellite optical communications system. The scheme of a simulating high precision beaconing light source modulated by liquid crystal is discussed in the paper in detail, at the same time presenting some analyses of the development trend on new and most advanced correlative technology, and pointing out that the liquid crystal technology will become one of the master technologies platform in the field of optical communications.
Aimed at the influence of turbulent atmosphere effect on laser pulse detection, it discusses the key factors that affect the signal test in this paper. Based on it, the article also discusses two key techniques, namely, floating threshold value and AGC (Automatic Gain Control) technology in detail, especially about the technique of floating threshold value. According to discussion about intelligent detection technology of laser pulse, the system designs a low noise detecting unit of laser pulse, tests its performance by the experiment, and validates correctness of the results.
The paper discusses the fundamental constitution of the later-atmosphere communication, which uses the semiconductor lasers as light sources and the photoelectric sensors as receiving devices. It makes a deep going study to the key technique -- that the problem of receiving the large-scale signals. To resolve this problem, the system uses plane mirrors, and hollow awls as the optical receiving aerial, at the same time; it makes an extensive-area photoelectric sensor whose diameter is 50 mm with 150 multiple photodiodes. The article also discusses and analyzes the technical difficulties in detail, which come from the extensive-area photoelectric receiving. The anti-light saturation of the extenive-area photoelectric sensors, the interference of background luminance and the problem of answering time. The system is successfully used in the practical engineering fields.