面向机载探测系统大视场光学成像的需求,开展了大视场光学成像系统光学设计、自由曲面光学元件超精密加工、形位误差同步检测以及系统集成与成像实验研究。首先,采用视场扩展法进行大视场自由曲面离轴反射光学系统的设计;其次,进行铝合金自由曲面反射镜纳米精度加工和高频抑制工艺探索,并实现了基于计算全息元件的自由曲面形位高精度检测;最后,进行了光学系统的装调集成与成像实验。结果表明,系统的视场角为30°×5°,全视场光学传递函数值大于 0。7,接近衍射极限,最大像元均方根半径为 2。075 μm,自由曲面光学元件的面形精度均方根(Root Mean Square,RMS)值优于20 nm,位置精度优于1 μm,装配集成后能够满足大视场高分辨的场景使用要求,同时具备稳定可靠和快响制造等特点。
Large field optical imaging system based on freeform surface optics
To achieve extensive field of view optical imaging,research has been conducted on a system uti-lizing free-form surface optical components.This research encompasses the optical design of such systems,ultra-precision machining of free-form surfaces,synchronous error detection in form and position,and sys-tem integration with imaging experiments.Initially,by studying the mechanism of aberration formation un-der multiple constraints,a precise model for the parametric description of free-form surface optical systems was developed.Subsequently,nano-precision machining and high-frequency suppression techniques were explored for aluminum alloy free-form mirrors,alongside high-precision shape and position detection using computer-generated holographic elements.Comprehensive experiments on system integration and imaging were performed.The results show that the system's field of view is 30°×5°,with an optical transfer func-tion value exceeding 0.7,approaching the diffraction limit,and a maximum pixel root mean square radius of 2.075 μm.The surface shape accuracy of the free-form optical components has an RMS value better than 20 nm,and position accuracy better than 1 μm.Post-assembly,the system fulfills the criteria for large field of view and high-resolution applications,also demonstrating stability,reliability,and rapid response in manufacturing.
optical ultra-precision machiningfree form surfaceComputer Generated Hologram(CGH)imaging system