An Integrated Manufacturing System for the Design, Fabrication, and Measurement of Ultra-Precision Freeform Optics

Abstract

Geometry complexity and high-precision requirement have imposed a lot of challenges for the design, manufacturing, and measurement of ultra-precision freeform surfaces with submicrometer form accuracy and surface finish in nanometer range. Successful manufacturing of ultra-precision freeform surface not only relies on the high precision of machine tools, but also largely depends on comprehensive consideration of advanced optics design, modeling, and optimization of the machining process, freeform surface measurement and characterization. Currently, there is still a lack of an integrated system to fill the gap between those different important stages for producing a complete optics part. This paper presents the theoretical basis for the establishment of an integrated platform for the design, fabrication, and measurement of ultra-precision freeform surfaces. The platform mainly consists of four key modules, which are optics design module, data exchange module, machining process simulation and optimization module and freeform measurement and evaluation module. A series of experiments have been conducted to evaluate the performance of the platform and its capability is realized through a trial implementation in the design, fabrication and measurement of an F-theta lens. The predicted values by the models in the system are found to agree well with the experimental results, and the freeform characterization results are also validated by the experiments. These show that the proposed integrated platform not only helps to shorten the cycle time for the development of freeform components but also provides an important means for optimizing the surface quality in the ultra-precision machining of freeform surfaces. With this system, optimal machining parameters, the best cutting strategy, and the optimization of the surface quality can be obtained without the need for conducting time-consuming and expensive cutting tests. This contributes to the advancement of the manufacturing and measurement technologies for the ultra-precision freeform surfaces.