Study on polarization accuracy and its influencing mechanisms of division of focal plane polarimeter

The division of focal plane (DoFP) polarimeter is a vital tool for polarization imaging due to its compact structure and stable performance. However, its detection accuracy is significantly influenced by fabrication and integration errors of the micro-polarizer array (MPA). To address this, we establish a clear relationship between the accuracy of DoFP polarimeter and error sources, including the integration alignment, integration distance, integration angle, transmission axis angles, and extinction ratio of the MPA. Using a novel mathematical model based on the finite difference time domain method, we quantitatively analyze the impact of these errors on polarization detection accuracy. Our results demonstrate that as the detection accuracy improves from 10^− 1 to 10^− 2 and 10^− 3, the required fabrication accuracy of MPA’s transmission axis angles and the integration accuracy both increase by approximately one order of magnitude. Additionally, to achieve same accuracy improvements, the extinction ratio of the MPA exhibits nonlinear growth, increasing by about 2.5 times and 20 times, respectively. These findings provide a critical foundation for error control and quantitative performance assessment in DoFP polarimeters, advancing their application in various fields.