Design of scanning visible continuous zoom optical system

To address the application requirements of visible-light imaging systems in wide-field-of-view search, target tracking, and detailed local observation, a continuous-zoom optical system was designed that utilized image-plane parallel-beam fast-steering mirror (FSM) scanning compensation. The system operates in the 450 nm~650 nm wavelength band and employs a configuration combining a front-end continuous-zoom telescope system with a rear-end imaging unit. Through the coordinated movement of the zoom group and the compensation group, 10× continuous zoom was achieved, forming a stable parallel light path on image plane, enabling FSM to perform high-speed scanning compensation with a relatively small aperture. The image quality at each focal length and the imaging performance under different FSM deflection positions were analyzed. The design results indicated that the system maintains good imaging quality across entire zoom range. The full-field transfer function at 60 lp/mm exceeded 0.5, image quality changed minimally during scanning process of fast-scanning mirror, satisfying the application requirements for visible-light scanning imaging, target tracking, and continuous magnification observation.