Generation of sub wavelength multiple focal hole segments using azimuthally polarized annular multi-Gaussian beam

We propose a new approach for generating multiple focal hole segment of sub wavelength size, by tight focusing of phase modulated annular multi-Gaussian beam. The focusing properties are investigated theoretically by vector diffraction theory. We observed that focal segment with multiple focal rings structure separated with different axial distance can be generated by properly tuning the phase of the incident azimuthally polarized annular multi-Gaussian beam. Potential applications of this focal shaping technique are also discussed.