Abstract：Micro-structured metallic-film multi-annular plate (MAP) is one kind of novel micro-/nanophotonic element, which can be applied in the fields of super-resolution optical focusing, nanoscopic imaging, and precision engineering measurement. A versatile, fast, vectorial optimization design method for MAP is described for modulating far-field super-resolution focusing spots and ultra-thin optical needles. It is applicable for a variety of vector beams such as linearly, circularly, and radially polarized beams. Rigorous electromagnetic validation method for MAP is established based on the three-dimensional finite-difference time-domain method, which accurately models the scattering process of light propagating within micro-structured metallic annular grooves. For light wavelengths ranging from deep ultra-violet to visible, an empirical selection rule of the metallic coating film for MAP is the aluminum film at a thickness within λ/10～λ/6.
2016, Vol. 37 
