Optimization methods for polarization aberration in underwater imaging optical systems

Underwater imaging is a vital technology for marine resource exploration, target localization, and ecological monitoring. To address the challenges of low-light conditions and strong scattering in underwater environments, large-aperture optical systems combined with polarization imaging are widely required. However, the polarization aberration induced in such optical systems limits the polarization descatter algorithms' performance, which restricts the underwater image quality. Herein, a kind of polarization aberration optimization method for underwater optical systems is proposed based on ray deflection angle modulation. The mathematical model correlating diattenuation with ray deflection angles is built to formulate a kind of polarization aberration control strategy by constraining the ray deflection angles at critical surfaces. It is validated with a typical underwater optical system design with a relative aperture of 1/1.6 and a full field of view (FOV) of  90°. The method proves effective in suppressing diattenuation and improving the accuracy of Stokes vector retrieval. This strategy provides a robust foundation for high-quality underwater image acquisition.