Generation of tunable focal holes by tight focusing of phase modulated azimuthally polarized double ring shaped beam

We investigated the focusing properties of a double ring shaped azimuthally polarized beam using a high NA lens and a dedicated binary phase filter. The definition of azimuthally polarized double ring beam is stated, and proposed with phase filter. The results have been presented for total intensity distribution and squares of the polarization components at the focal plane of a high numerical aperture system, for values of the topological charge. Focusing beam results in the stretching of the intensity pattern as well as of the squares of the polarization components. We observe that by using 3 belts and 5 belts binary phase filters novel focal patterns including multiple ring structures and focal splitting are obtained. this kind of system is worthwhile for manipulation of nano particles, trapping and for building nano structures for NEMS applications.