Effect of light-beam deviation on the instrument matrix of the four-detector photopolarimeter

Abstract

Analytical geometry, ray tracing, and the Mueller-matrix calculus are used to determine the calibration matrix of the four-detector photopolarimeter (FDP) when the incident light beam deviates from the optical axis of the instrument. Detectors of the FDP are represented by their surface equations in Cartesian coordinates. The instrument matrices corresponding to angular deviations of Ϯ0.5 and Ϯ1.0 deg in reference horizontal and vertical planes, and their differences from the unperturbed matrix are given for two FDP configurations. Output Stokes parameters that correspond to several typical input states of polarization are calculated to demonstrate the effects of light-beam deviation.