Detection of birefringence singularity by supercontinuum vector beam

We demonstrated detection of birefringence singularity on the space-variant retarder with an inhomogeneous birefringence distribution by supercontinuum vector beam. The birefringence measurement by supercontinuum vector beam analysis provides kinematics of a singularity point on the space-variant retarder. We conducted numerical calculations and experiments for proof of principle. The calculated results were characterized by relative positions with (x(o), y(o)) between the singularity point and the vector beam. In the experiments, we measured the retardance and the azimuthal angle from intensity profile on a single-shot image captured at wavelengths of lambda = 450, 550, and 650 nm. The retardances at lambda = 450 nm and 550 nm were changed from Delta = 112 degrees to 131 degrees and from Delta = 120 degrees to 152 degrees when the x o displacement of the space-variant retarder moved from 0 to 350 mu m. The measured retardance corresponded with the calculated results in the function of the position of birefringence sin gularity. (C) 2020 Optical Society of America