Fringe locking system with large phase compensation range for holographic exposure systems with arbitrary recording wavefronts

Breaking through the difficulty of long-term stable exposure in holographic interference systems is of great significance for the production of large-sized and high-precision holographic optical element (HOE). This paper proposes a fringe locking system that can compensate for large scale phase drift in a closed-loop manner. It can be applied to holographic interferometric systems with arbitrary recording wavefront to effectively suppress the performance degradation of HOE caused by interference fringe smearing. The fringe locking prototype based on piezoelectric ceramic displacement stage has verified the feasibility of the proposed method and system. The compensation range for fringe drift is expanded to 5-6 periods through signal processing. Holographic exposure of HOE with arbitrary recording wavefront up to a maximum area of 300 mm × 300 mm can be achieved by reference HOE. Furthermore, the control period of the fringe locking system is within 10ms, and the phase compensation accuracy can reach up to 0.0071rad. Moreover, the relative diffraction efficiency of HOE can be improved by about 25% before and after the system is turned on. This fringe locking system has strong universality and is expected to be applied in optical precision manufacturing fields such as holographic large-size single exposure and holographic scanning interference lithography.