Scanning visible polarization-direction-modulation polarimeter for optically active media measurement

Abstract

An experimental method to automatically recognize the polarized direction of visible linearly polarized light was presented, for the linearly polarized light vibrating in the vertical direction, the experimental results show that the measurement accuracy and precision are 0.143° and 0.016°, respectively. Based on this method, taking advantage of a beam splitter with a 50:50 splitting ratio, two half-wave plate, two identical isosceles prisms with two basic angles of the critical angle, a precision rotating stage and so on, an experimental setup with dual optical paths was proposed. The concentration measurements of glucose solutions are completed in the range of 5%–25%, at intervals of 5%, and the experimental results show that the maximum relative error is about 3.60%. In comparison with the conventional single-channel homodyne interferometer and dual-channel phase interrogation polarimeter, this approach has the advantages of directly measuring the rotation angle of vibration plane of linearly polarized light and strong ability of anti-environment interference.