Research on the Angle Measurement Accuracy of Laser Seekers Based on Electrowetting Dual-Liquid Dynamic Zoom Systems

Traditional zoom semi-active laser seekers cannot adaptively adjust the spot size while maintaining a compact structure, which degrades angle measurement accuracy. This paper proposes a method based on aberration theory to analyze angle measurement designs an electrowetting dual-liquid zoom optical system that meets compactness constraints. The dynamic curvature control architecture replaces traditional mechanical zoom to achieve optimal detection spot for four-quadrant detectors throughout the entire trajectory. The Gaussian bracket method is employed to calculate and distribute the total optical power of the system, and a dynamic zoom optical system meeting compactness requirements is designed and simulated. Quantitative equations relating the spatial position of the liquid lens to aberrations are derived. A global optimization of the liquid lens zoom optical system for the seeker is performed on the ZEMAX 2024 platform, enabling the system to meet the detection requirements of the entire trajectory through voltage control. Design results show a total system length of 61.6 mm, with distortion controlled within 0.1% during continuous focallength adjustment from 30 to 57 mm. A quantitative evaluation model for aberration-induced angle measurement error is established, and calculations indicate a 62.8% reduction in the RMS angle measurement error over the full zoom range.