Vector diffraction modeling and parametric study of 266 nm sub-wavelength pinholes for high-NA wavefront sensing

A rigorous full-vector electromagnetic model, integrating the Richards–Wolf integral and 3D-FDTD methods, is employed to optimize sub-wavelength pinholes for 266 nm high-NA wavefront sensing. Through systematic analysis, it is demonstrated that while wavefront quality is dictated by the diameter, high-frequency aberrations are effectively suppressed by optimal thickness via waveguide mode cutoff. Crucially, significant deviations of the actual output NAs from scalar predictions are observed across diffraction-dominated and geometric projection regimes. Furthermore, both transmittance and wavefront purity are simultaneously enhanced by moderately tapered sidewalls (∼86 ∘ ). Ultimately, robust numerical design guidelines for deep ultraviolet (DUV) 266 nm reference sources are established by overcoming traditional scalar limitations.