Effect of spherical aberration in tight focusing of azimuthally polarized double ring shaped beam

The dark core of a tightly focused azimuthally polarized beam is studied in the presence of third-order spherical aberration, using vectorial Debye-Wolf integral. Compensation for the effect of spherical aberration has been studied in the presence of defocusing. The Effect of spherical aberration on the intensity distribution can be compensated by choosing a proper value of defocusing, and this compensation generates the focal hole as same size (FWHM) and shape almost equal for the aberration free cases however it takes focal shift along the optical axis. Some results are also presented for the influence of truncation parameter of the beam, on the point spread function at different observation planes. The author expects such investigation is worthwhile for optical manipulation and material processing technologies.