摘要
根据液体透镜稀疏孔径成像的特点,提出一种辐射状多子镜阵列结构;给出稀疏孔径成像的简化模型,通过多子镜结构的光瞳函数,得出调制传递函数的解析表达式;给出此多子镜阵列结构的具体分布形式,采用无量纲方法对结构参数进行约化;讨论2种辐射状多子镜阵列的结构情况,计算填充因子、冗余度、调制传递函数和其他特性参数;讨论参数扫描所表现的物理现象,并对比这2种阵列的结构特征和成像特性;对辐射状多子镜阵列结构和复合环形结构的特性指标进行比较。结果表明:在2种结构的平均调制传递函数以及调制传递函数中频特性值相接近的情况下,选择具有更大实际等效口径和实际截止频率以及更低冗余度的Ⅱ型结构;Ⅱ型结构在成像方面具有一定优势;由于基于液体透镜的多子镜阵列结构采用无量纲约化参数,因此结论普适于任意的包围圆尺寸;与复合环形结构相比,当填充因子相同时,辐射状多子镜结构有更大的实际截止频率和实际等效口径。
This study proposes a radial multi-sub-mirror array structure based on the sparse aperture imaging characteristics of a liquid lens.A simplified model of sparse aperture imaging is given,and the analytical expression of the modulation transfer function(MTF)is deduced according to the pupil function of the multi-sub-mirror structure.Subsequently,a concrete distribution of the multi-sub-mirror array structure is given and the structure parameters are simplified using a dimensionless method.The structures of two types of radial multi-sub-mirror arrays are discussed.The calculations of the fill factor,redundancy,MTF,and related characteristic parameters are completed.Moreover,the physical phenomena represented by the parameter scanning are discussed.The structural and imaging characteristics of these two arrays as well as the characteristics of the radial multi-sub-mirror array structure and the composite ring-shaped structure are then compared and analyzed.Results show that:when the average MTF of these two structures and the frequency characteristic values in MTF are similar,the type II structure with larger actual equivalent aperture,actual cut-off frequency,and lower redundancy should be chosen;the type II structure has some advantages in imaging;because the multi-sub-mirror array structure based on a liquid lens adopts dimensionless simplification parameters,the conclusion is generally suitable for arbitrary size of enclosing circle;compared with the composite ring-shaped structure,the radial multi-sub-mirror structure has larger actual cut-off frequency and equivalent aperture when the fill factors are the same.
作者
刘肖尧
梁忠诚
郝未倩
赵瑞
孔梅梅
陈陶
张月
Liu Xiaoyao;Liang Zhongcheng;Hao Weiqian;Zhao Rui;Kong Meimei;Chen Tao;Zhang Yue(College of Electronic and Optical Engineering & College of Microelectronics,Nanjing University of Posts and Telecommunications,Nanjiyig,Jiangsu 210023,China;Beijing Institute of Space Mechanics and Electricity,China Academy of Space Technology,Beijing 100094,China)
出处
《光学学报》
EI
CAS
CSCD
北大核心
2019年第8期150-158,共9页
Acta Optica Sinica
基金
国家自然科学基金(61775102)
关键词
成像系统
调制传递函数
液体透镜阵列
稀疏孔径
光瞳函数
imaging system
modulation transfer function
liquid lens array
sparse aperture
pupil function
