应用费希尔信息量评价函数的波前编码系统设计

Design of Wavefront Coding System Based on Evaluation Function of Fisher Information

在兼顾图像恢复能力的基础上,将不同物距下点扩展函数相似性的评价函数费希尔信息量(Fisher Information,FI)应用到波前编码实际光学系统相位板的优化设计中。在焦距和孔径之比为3、有效焦距为100 mm的无穷远成像的双胶合系统的基础上,设计得到了双胶合-波前编码系统。通过解码前后的点扩展函数模拟和实验结果表明,该系统在5 m到无穷远的物距范围内很好地调制了系统的点扩展函数,使得它对物距不敏感。最后通过对位于5 m,10 m和15 m的三人分别进行传统双胶合成像和双胶合-波前编码系统的成像实验对比,有力地证明了双胶合系统的清晰成像的物距范围从10 m到无穷远扩展到5 m到无穷远,这使得光学系统景深得到很大的延拓。

Considering the imaging restorability, Fisher Information （FI） to evaluate similarity of the point spread functions （PSFs） of different object distances is used to optimize the design of phase mask in practical wavefront coding （WFC） system. A doublet-wavefront coding system is designed based on an infinite focused doublet system with f number 3, effective focal length 100 mm. The simulation and experimental results of encoding and decoding point spread functions show that the doublet-wavefront coding system is insensitive to the object distance with the modulation of point spread function. With object distance from 5 mm to infinite. 3 people （5 m, 10 m, 15 m far a way ） are imaged using traditional doublet and doublet-wavefront coding system respectively. The results show that the sharp imaging＇s object distance of the doublet-wavefront coding system ranges from 5m to infinite, while the doublet system ranges from 10 m to infinite. In this way the field depth is greatly extended.