Measuring the optical rotation angle and circular dichroism of anisotropic optical media using a heterodyne polarimeter

A method is proposed for measuring the circular birefringence (CB) and circular dichroism (CD) properties of anisotropic optical samples using a heterodyne polarimeter and an electronic signal processing scheme. Importantly, the CB and CD properties of the sample are decoupled in the analytical model, and thus the accuracy of the measurement results is improved. Furthermore, the proposed method enables the CB and CD properties of the sample to be measured over the full range. The validity of the proposed method is demonstrated by measuring the optical rotation angle and circular diattenuation of pure CB and CD samples and a composite sample with both CB and CD properties. The standard deviations of the optical rotation angle and circular dichroism are found to be 3.07× 10^-3 degrees and 9.3× 10^-4 for a hybrid CD/CB sample, respectively.