Figure 3.
(a) Generation of a sub-diffraction longitudinal spot by focusing the radially polarized wave with a planar binary phase lens; (b) the micro lens structure; (c) the micro lens physical model for COMSOL numerical simulation.
(a) Generation of a sub-diffraction longitudinal spot by focusing the radially polarized wave with a planar binary phase lens; (b) the micro lens structure; (c) the micro lens physical model for COMSOL numerical simulation.