Advances in rotating Risley prisms for space-optics applications

As a refractive beam steering technology, Risley prisms have garnered significant attention in spatial optical fields such as laser tracking and targeting, robotic guidance, and autonomous driving environmental perception due to their compact structure, high pointing accuracy, and strong vibration resistance. (1) This review systematically addresses fundamental issues in Risley prism systems, including beam pointing mechanisms, scanning patterns, beam distortion, blind zones, control singularities, chromatic aberration correction, and Opto-Mechanical system design. The comprehensive establishment of foundational solutions such as forward/inverse kinematic models and closed-loop tracking technologies for Risley prisms has enabled their potential applications in high-precision scanning domains. (2) We elaborate on typical applications of Risley prisms in free-space laser communications, variable-scale scanning, LiDAR, dynamic target tracking, and broadband imaging, with case studies from aerospace, defense, and autonomous systems. (3) Considering the technical challenges and application prospects of rotating Risley prisms, future development directions are proposed for advancing this technology across multiple frontiers of spatial optics. We provide a comprehensive reference for advancing Risley prism–based space optical technologies.