Calculated results for STED microscopy using high-order ASPVBs (P = 5), where (a) excitation spot is formed by focusing ASPVBs (l = 3), (b) doughnut-shape de-excitation spot is formed by focusing ASPVBs (l = 2). (c) The line scan of intensity distributions for panels (a) and (b). (d) Remaining focal area allowing fluorescence.