White-light circular-polarization imaging using pairs of polarization gratings and wedge prisms

A novel, to the best of our knowledge, method for circular-polarization imaging with white light is presented. The vital optical elements of the proposed system are two polarization gratings (PGs) and a wedge prism. The chromatic dispersion of the PG diffraction angle is compensated by the difference of the grating period for the two PGs. In addition, the distance between the diffracted lights on the imaging plane is controlled by using a wedge prism. As a result, ${S_3}$S₃ of the Stokes parameter, including the wavelength dependence of a scarab beetle, was observed at a time, and the ${S_3}$S₃ contribution to each color was determined by using the color filter of the light-receiving element. Because the white-light polarization image includes a lot of information about the illuminated structure, the proposed method should be applied to biomedical sensing and remote sensing.