液体透镜变焦系统高斯理论分析

Gauss Theoretical Analysis of Liquid Crystal Lens Zoom System

基于液体透镜的变焦系统不需要移动光组即能实现变倍的功能,这种变倍工作方式可应用于具有特定需求的成像系统,近年来备受关注。探讨了液体透镜参数(变焦范围,通光口径)对变焦系统变焦性能的影响,从理论上得到了液体透镜变焦系统最大变倍比以及最大视场角的计算公式。根据理论计算的结构,求得该结构下液体透镜变焦系统的变焦曲线表达式。从变焦曲线可知,系统从短焦向长焦方向变化时,系统变倍比增长速度越快,系统焦距变化越灵敏。利用上海理工大学研发的液体透镜进行仿真,设计了一款变倍比为6,全视场角为60°的液体透镜变焦系统高斯结构。该设计不仅验证了理论推导的正确性,也可作为实际液体透镜变焦系统的初始结构。

Zoom system based on liquid crystal lenses can realize zoom without moving elements.This zoom working mode is applicable to some specific imaging systems,and has attracted much attention in recent years.The effects of liquid crystal lens parameters including zoom range and clear aperture on zooming performance of zoom system are studied.The calculation formulas of the maximum zoom ratio and the maximum field of view of the liquid crystal lens zoom system are theoretically obtained.According to the theoretically calculated structure,the zoom curve expression of the zoom system is obtained.The zoom curve shows that the zoom ratio grows faster and the focal length varies more sensitively when the system changes from short focus to long focus.Using the liquid crystal lenses developed by the University of Shanghai for Science and Technology,we design a Gauss model of liquid crystal lens zoom system with zoom ratio of 6 and full field of view of 60°.The design does not only verify the theoretical derivation,but can also be used as the initial structure of an actual liquid crystal lens zoom system.