On the propagating and evanescent waves associated to azimuthally-polarized nonparaxial fields

We investigate the contributions of the propagating and the evanescent waves associated to freely-propagating nonparaxial light beams whose transverse component at some plane is azimuthally polarized. In terms of the plane-wave angular spectrum of these fields, analytical expressions are given for determining both the spatial shape of the above components and their relative weight integrated over the whole transverse plane. The results are applied to a kind of doughnut-like beams with transverse azimuthal polarization.