Full Poincaré beams II: partial polarization.

Optical fields whose coherence and/or polarization properties appear to change under propagation have intrigued researchers for many years. We describe and experimentally demonstrate a class of optical fields whose polarization content at any transverse plane spans a disk-like region within the Poincaré sphere. When examined through a paraxial focal region, the disk rotates under propagation, spanning all possible states of polarization. We map the change in Stokes parameters through focus for each case, comparing experiment with the theoretical predictions.