Abstract
Optical skyrmions are widely investigated in topological photonics, yet generating their vector textures in three dimensions purely within the electric field remains a challenge. Here, we show that a single-layer dielectric metasurface can overcome this constraint through a zonal modulation strategy to decouple focal field control. By using a low numerical aperture (NA) inner core largely governing the transverse field and a high-NA outer ring mainly contributing to the longitudinal field, highly pure Néel-type and Bloch-type electric field skyrmions are successfully generated. This zonal design strategy clarifies how tightly focused vector fields can be decomposed into separate transverse-texture and longitudinal-polarity functions, providing a compact route for generating electric-field skyrmions with flat optics.