Modifying Bessel beam profiles with a spherulite-based radial polarizer

We present a radial polarizer prepared by growing a thickness-constrained spherulite from an oleoresin polymer. As an insert between crossed linear polarizers, the fabricated device is used to alter the intensity profile of an incident zero-order Bessel beam. Radially polarized output beams have an intensity profile with a pronounced singularity at the center. Beams may be rotated by a simple reorientation of the crossed polarizers. Experimental results with our radial polarizer correspond to a transformation of the Bessel beam order from l=0 to l=2.