Proceedings Article | 18 December 2023
KEYWORDS: Polarization, Error analysis, Imaging systems, Polarization imaging, Matrices, Wave plates, Poincare sphere, Reflection, Incident light, Ferroelectric LCDs
The ferroelectric liquid crystal (FLC)-based wide spectrum polarization imager can quickly acquire the full polarization information of the target, however, the polarization elements error will affect the accuracy of the system polarization parameters (DOP, EOP, and AOP) measurement. In this paper, to investigate the influence of polarization element error on the acquisition of polarization information of the measured target, the influence of element parameter error on the measurement of target polarization parameters is analyzed. First, the working principle of FLC and the structural composition of the system of wide spectrum polarization imager based on FLC are introduced; second, the measurement matrix of the wide spectrum polarization imaging system is calculated based on the CCD spectral response curve, and the variation of the wave plate phase retardation with wavelength; then, the error model of the system for solving the full polarization parameters is established; finally, the effects of the parameter (azimuth angle F1θ, tuned rotation angle F1α, phase retardation F1δ of FLC2; azimuth angle Hθ, phase retardation Hδ of HWP; azimuth angle F2θ, tuned rotation angle F2α, phase retardation F2δ of FLC2; azimuth angle Qθ, phase retardation Qδ of QWP; azimuth angle Pθ of P) errors of each element of the polarization module on the DOP, EOP, and AOP measurements are analyzed. The simulation results show that: with the increase of the error of each element parameter of the polarization module, the measurement error of the polarization parameters are all increasing in different degrees; the error of F2α is the main factor affecting the measurement accuracy of the degree of polarization (DOP), the error of F1α is the main factor affecting the measurement accuracy of the ellipticity of polarization (EOP), and the error of F1θ is the main factor affecting the measurement accuracy of the angle of polarization(AOP); at [-2°,2°], the maximum measurement errors of DOP, EOP, and AOP are 2.83%, 6.98%, and 9.26%, respectively; when the errors of polarization element parameters are certain, the measurement errors will change with different polarization states of the target. The research method and results can provide research ideas and theoretical references for the error analysis research of the wide spectrum polarization imaging system based on FLC or other wide spectrum polarization imaging systems.
