Radially Polarized Laser Beam Intensity Distributions

diffraction angle ϵ

This Demonstration compares the axial and radial field intensities in the focal plane of a radially polarized (axicon) laser beam with increased focusing or, equivalently, as the diffraction angle is increased. Such a beam has two electric field components: axial (along the propagation direction) and radial (transverse to the propagation axis). When the beam is focused to a spot size smaller than would be allowed by the paraxial approximation, it develops a pencil-like axial focus within which the intensity increases (with further focusing) at the expense of the radial intensity.