Wavefront Coding Based Strong Backlight Target Detection

Under reverse light conditions, the incident light energy from the target is substantial, leading to saturation in existing detectors. This saturation can cause damage and impair the detectors, resulting in an inability to effectively perceive the potential threat of reverse light. Currently, installing lens covers on the detectors is the primary approach, but it has limitations in terms of detection range and applicability. To address these challenges, this paper proposes an optical detection method based on wavefront coding, leveraging its directional dispersion, strong light suppression, and near-lossless restoration characteristics. This method enables the detection and verification of backlight targets. Additionally, a design optimization method for an aspherical phase mask is introduced. By incorporating the surface function in the calculation, the point spread function of different surface phase masks is derived. This allows for the advanced prediction of the static model of the wavefront coding optical imaging system after the insertion of the phase mask. Experimental verification demonstrates that the aspherical phase mask can suppress high-light targets by over 200 times and successfully restore the image. This novel approach surpasses the limitations of traditional lens covers by effectively perceiving and addressing reverse light conditions.