光学系统偏振像差的校正、补偿和全局优化设计方法

Currently, optical design and image quality evaluation methods are mainly based on scalar diffraction theory and do not consider the polarization of light. However, it has been found that many optical systems are polarization-sensitive, especially for high-performance optical systems with high numerical aperture, large incident angle, and non-paraxial applications. Polarization aberrations have become a major problem affecting their optical imaging quality and system performance. In addition, for an optical system that uses polarization as an information carrier, polarization aberrations will cause system errors and become a bottleneck limiting the performance improvement of polarization optical instruments. The lack of the correction, compensation, and global optimization design methods of the polarization aberration severely constrain the design of high-performance optical systems and the efficient use of polarization characteristics. Therefore, this project intends to construct an optical system based on the theory of vector wave diffraction based on coherence matrix. The complete vectorization model gives the mathematical representation of the three dimensional polarization aberration function, reveals the effects and laws of polarization aberration on the wave aberration, point spread function and modulation transfer function of the optical system, constructs an evaluation function for correcting polarization aberration, and a damping factor. As well as weighting factors, the compensation and correction algorithms for residual aberrations are studied to achieve automatic balance, correction, and global optimization of polarization aberrations, which lays a theoretical foundation for the optimization of designing high-performance polarization-sensitive optical systems and polarization imaging systems.

目前，光学设计和像质评价方法主要基于标量衍射理论，并不考虑光的偏振。然而研究发现很多光学系统都是偏振敏感的，特别是对于具有高数值孔径、大入射角、非近轴运用等特点的高性能光学系统，偏振像差已成为影响其光学成像质量和系统性能的重要因素。此外，对于以偏振为信息载体的光学系统，偏振像差将引起系统误差，成为限制偏振光学仪器性能提升的瓶颈。偏振像差的校正、补偿及全局优化设计方法的缺失严重制约了高性能光学系统的设计和对光场偏振特性的有效利用，因此本项目拟从矢量波衍射理论出发，基于相干矩阵构建光学系统的完全矢量化模型，得到三维偏振像差函数的数学表征，揭示偏振像差对光学系统波像差、点扩散函数和调制传递函数的影响及规律，构造校正偏振像差的评价函数、阻尼因子以及权因子，研究残余偏振像差的补偿和修正算法，从而实现偏振像差的自动平衡、校正和全局优化设计，为优化设计高性能的偏振敏感光学系统和偏振成像系统奠定理论基础。

传统的光学设计和像质评价方法主要基于标量衍射理论，并不考虑光的偏振。然而对于具有高数值孔径、大入射角、非近轴运用等特点的高性能光学系统，偏振像差已成为影响其光学成像质量和系统性能的重要因素。此外，对于以偏振为信息载体的光学系统，偏振像差将引起系统误差，成为限制偏振光学仪器性能提升的瓶颈。本项目从矢量波衍射理论出发，基于相干矩阵构建了光学系统的完全矢量化模型，得到了空间任意采样点处振幅、位相、偏振等信息的完整表征；构建了三维偏振光追迹张量，表征了光学元件、光学界面或光学系统对偏振光的作用矩阵。进一步建立了全局坐标系下的三维偏振光追迹方法，获得了偏振像差函数的数学表征。基于偏振像差的数学模型，以两种典型的偏振敏感系统（大气遥感偏振激光雷达中的望远系统，和高数值孔径显微成像系统）为例，分析了偏振像差函数与其光学系统结构参数的关系，精确定量计算了光学系统偏振像差的来源及其权重，分析了偏振像差对点扩散函数的影响和规律。建立了光学薄膜的消偏振优化设计数学模型，将膜层厚度设为随机变量，通过修正交叉算子、变异算子和遗传代数等参数，选择最佳优化参数结构，有利于快速的寻找目标函数最优解。结合二向衰减函数、位相延迟函数以及方向泽尼克函数，构造了校正偏振像差的评价函数。并基于遗传算法和粒子群算法，提出了一种偏振像差的协同优化设计方法。在光学设计阶段实现了偏振像差的自动平衡、校正和全局优化，为优化设计高性能的偏振敏感光学系统和偏振成像系统奠定了理论基础。