液晶光学相控阵的高功率波束指向特性研究

Research of liquid crystal optical phased array beam steering characteristics with high power laser incidence

摘要:

针对液晶光学相控阵LCOPA（Liquid Crystal Optical Phased Array）在高功率激光入射场景下的波束指向特性，构建了LCOPA的热力学模型，利用Ericksen Leslie动力学理论和液晶材料的温度特性，对不同入射激光功率和不同液晶材料条件下LCOPA的近场相位分布、远场偏转效率和偏转响应过程进行数值仿真分析。结果表明，当入射激光功率从50 W 增加到 110 W时，近场相位分布趋于恶化，远场偏转效率从96.8%下降到41.3%；5PCH、UCF-35、MLC-624-000三种液晶材料的温度敏感性逐渐减弱，远场偏转效率分别为41.3%、92.3%、98.8%；同时，入射激光功率的增加会缩短相控阵器件的下降时间，而对其上升时间和切换时间无明显影响。

Abstract:

Focusing on LCOPA（Liquid Crystal Optical Phased Array）beam steering characteristics with high power laser incidence, the thermodynamic model of liquid crystal optical phased array is established in this paper. According to Ericksen Leslie theory and temperature characteristics of liquid crystal materials, the phase distribution in near field, deflection efficiency in far field and response process of LCOPA are analyzed by numerical method under the condition of different incident and different liquid crystal materials. As a result, when the incident laser power increases from 50 W to 110 W, the phase distribution in near field tends to deteriorate and the deflection efficiency in far field decreases from 96.8% to 41.3%. Among three liquid crystal materials, 5PCH, UCF-35, MLC-624-000, the deflection efficiency in far field is 41.3%, 92.3% and 98.8%, respectively, with their temperature sensitivity gradually decreasing. Meanwhile, when incident laser power rises, the drop time of LCOPA is shortened and the rise time and switch time are not significantly affected.