Ultra-precision machining technology of freeform optics and its applications

As a breakthrough to the traditional optical design, the application of freeform surface in optical imaging system had greatly improved the imaging quality and transmission efficiency of the optical system. Ultra-precision machining technology provided the solutions to the fabrication of freeform optical element. In the present study, a high precision computation method had been developed to calculate the control points for freeform surface. A tool path generation module was developed for freeform surfaces, as well as an auto NC code generation system. A model-based system was built-up to predict the 3D topography of the surface generation and hence the optimization module was developed to achieve the better surface finish and form accuracy. A series of methods were developed to measure and evaluate the quality of different types of freeform surfaces. Based on the above research results, an integrated system for optical design, fabrication and measurement of freeform optics was established. The present research work will contribute to and advance the development of ultra-precision machining and nano-scale surface measuring of complex freeform surfaces element.