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Realizing low-distortion in wide-angle lens with freeform optics technique

Distortion is one major shortcoming of conventional wide-angle lens. The correction of distortion can maximize field of view in a wide-angle lens and benefit natural scenes. In this paper, we propose a compact wide-angle lens utilizing freeform surfaces to address the shortcoming. The design approaches, including the starting point selection, freeform surface conversion scheme, and system optimization, are discussed in detail. Moreover, freeform diagnostic tools are developed aiming to facilitate system optimization and visualize the critical aspects of optical performance. The simulation results are demonstrated and discussed. Analysis results demonstrate that the design strategies proposed in this paper have been shown to be effective in reducing distortion as well as improving optical performance. We envision that the proposed design schemes will have a positive effect on research and application values for wide angle lens system.