Polarization aberration analysis and suppression of an infrared remote sensing optical system based on a digital micro-mirror device

Abstract

The off-axis polarized infrared remote sensing imaging system based on a digital micro-mirror device (DMD) is capable of obtaining super-resolution images and enhancing the acquisition of target details. Polarization aberrations can reduce system resolution and affect target detection accuracy, it is more obvious in infrared imaging optical systems with small F-numbers and large incidence angles. It is complex to analyze and suppress the inherent polarization aberrations of infrared optical systems. To address this challenge, we propose a simplified polarization analysis method to get the aberration coefficients by using the specific pupil’s aberration value. The ray sampling rate of simplified method is 0.02 times that of traditional method, and the accuracy is almost unchanged. A method using weak polarization elements to suppress polarization aberrations is developed. Compared to the values before suppression, there is a reduction of more than 50% in diattenuation and retardance under different wavelength and fields. The shift of PSF centroid reduces over 55%, and the ellipticity of PSF decreases over 40%. Furthermore, the implementation of this technique has resulted in 28% improvement in the accuracy of measuring the degree of linear polarization (DoLP) of the optical system.