Generation of Multiple Focal Hole Segments Using Double-Ring Shaped Azimuthally Polarized Beam

摘要

We investigated the focusing properties of a double-ring-shaped azimuthally polarized beam tightly focused with a high NA lens and a binary phase filter.We observe that by using 3 belts and 5 belts binary phase filters novel focal patterns including splitting of focal rings and multiring focus are obtained.We also found that a suitably designed phase structure can shift the focal rings along optical axis.The author expects such investigation is worthwhile for optical manipulation and material processing technologies.