Phase encoding for sharper focus of the azimuthally polarized beam

We demonstrate that a sharper focal spot area can be generated (0.147 lambda(2)) by using an azimuthally polarized beam propagating through a vortex 0-2 pi phase plate than for radial polarization (0.17 lambda(2)) or for linear polarization (0.26 lambda(2)) under the same condition. Further research illustrates that such optimistic results can still be expected when condition limitations are liberalized. This will facilitate new approaches to get superresolution in confocal systems. (C) 2010 Optical Society of America