Complex vector beams, categorized by their inhomogeneous spatial distribution of polarization, have captivated remarkable research interest due to their numerous applications. In this study, a single-shot, common-path, and efficient method is proposed and demonstrated for the measurement of enantiomeric impurity utilizing cylindrical vector vortex beams. As the interaction of the enantiomers with the linear polarization induces opposite-handed optical rotations to the polarization, the change in the enantiomeric impurity of the enantiomeric solution directly controls the resultant optical rotation and thus the spatial distribution of polarization of the vector beams. Utilizing the relative rotation of the lobe patterns formed by the projection of the vector beams on a particular linear polarization state, the information about the quantity of the impurity present in the enantiomeric mixture is directly extracted. The estimated impurity obtained using our proposed experimental scheme aligns well with the values measured using the conventional high-precision polarimeter. In the proposed experimental scheme, the resolution in the detectability of enantiomeric impurity is 0.64%. The proposed experimental method remains valid for even weakly chiral materials. This advanced single-shot technique delivers quick and accurate knowledge of enantiomeric impurity, which may find utility in complex chiral compound synthesis, pharmaceutical applications, and medical diagnosis.
Karmakar et al. (Mon,) studied this question.