Algorithms for calculating polarization direction based on spatial modulation of vector optical field

Polarization is an important property of electromagnetic waves, and measuring their polarization properties fast precisely a very issue in many applications, such as skylight navigation, optical activity measurement, imaging polarimetry, spectroscopic ellipsometry, fluorescence immunoassay . The measurement method based on vector field modulation image processing new type spatial detection technology. key step this technique moving to practical application determined by effective algorithms with high speed accuracy. In order find out the calculating direction, principle direction introduced briefly, basic characteristics spatially modulated intensity distribution images are analyzed. According image, we propose implement four different calculation methods, which Radon transform, curve detection, radial integration, correlation also introduce working principles physical thoughts elaborately. To compare detailed performances these algorithms, experimental setup constructed collect perform algorithm verification, stabilities, speeds accuracies compared. research results indicate that all methods can achieve stable reliable detections. three integration accuracy better than 0.01° have relatively best comprehensive , most promising realize real-time high-precision measurement.