Simultaneous measurement of optical rotation angle and retardance

Abstract

In this study, an optical scheme based on Stokes–Mueller Formalism and rotating wave-plate Stokes polarimeter is successfully developed to simultaneously measure optical rotation angle and retardance. The average relative errors in the measured rotation angle and retardance of a half-wave plate which are solved by nonlinear equations of detected Stokes parameters are determined to be just 0.74% (1.16% for a perfect half-wave plate with retardance of 180°) and 0.40% respectively. The average relative error in the measured rotation angles of glucose solutions with concentrations ranging from 0 to 1.2g/dl is determined to be 4.53% (2.98% under calibration with sample cell). From the inspection of simultaneous measurement of rotation angle and retardance in a glucose solution followed by a half-wave plate, the average relative error in the measured rotation angles of glucose solutions is determined to be 4.23% (1.81% under calibration with sample cell). The correlation coefficient between the measured rotation angle and the glucose concentration is found to be 0.99966, while the standard deviation is just 0.00357°, and the average relative error in the measured retardance of a half-wave plate is determined to be just 0.47%. Consequently, the derived algorithm for simultaneously measuring rotation angle and retardance is feasible, and the developed system is evaluated with a precision of 10% approximately in rotation angle and a high precision of 0.0032% in retardance measurement.