Research About Liquid Crystal Phased Array Modeling And Performance Analysis

Optical phased array (OPA) technology because of its advanced technology hasbeen more and more used in the laser radar、adaptive optics、optical pattern recognition、optical communication and other fields. Liquid crystal optical phased (LCOPA) as oneof phased array technology with good research prospect, and began to become aresearch hot spot at home and abroad from the end of last century. Liquid crystal opticalphased array technology change the liquid crystal director by low driving voltage, thephase of incident laser beam is modulated, so as to make the beam rapid, accurate andflexible deflection in the particular direction and scope.In this paper, the liquid crystal phased array modeling and performance analysishave been investigated:1. Liquid crystal electro-optical properties and the liquid crystal characteristiccurve are studied, the measurement method of liquid crystal liquid crystal characteristiccurve is designed and used. Wave-front phase modulation models are set up, and thebinary blazed grating system model and the microwave phased array model areanalyzed and carried on the comparison. Rayleigh-sommerfeld diffraction is analyzedand divided to fresnel diffraction and fraunhofer diffraction.2. The dual beam、four beam and multiple beam models are established based onliquid crystal phased array, the simulation and experiments are carried out. Large anglebeam deflection methods are studied and the model based on two pieces of liquidcrystal phased array cascade is proposed. And the2-d deflection model is designed.3. The liquid crystal cell model is established, pointing angle of liquid crystalmolecules is calculated and the liquid crystal characteristic curve is simulated. Theimpact factors of Liquid crystal optical phased are analyzed and the impact on theprecision of beam deflection are calculated and simulated.4. A combination model of various factors is investigated and the distortedwave-front phase is simulated. The influence of the far field intensity of traditionalsingle beam deflection model and dual beam deflection model are analyzed. A novelphase iterative algorithm is proposed to improve performance of LCOPA. Compared with the conventional methods, the proposed algorithm is able to improve steeringefficiency, steering accuracy and reduce phase deviation respectively at the same time.Experiments and simulated results demonstrate that the performance optimizationalgorithm is useful.