Converting evanescent waves into propagating waves by hyper-hemi-microsphere.

Hyper-hemi-microspheres (HHMS) have shown promise in enhancing super-resolution imaging when combined with conventional optical microscopy. To offer actionable guidance for optimizing HHMS and hold broad applicability in the field of super-resolution imaging, the mechanism underpinning the enhanced imaging facilitated by HHMS is revealed by deriving the conversion and transmission conditions for evanescent waves. This is achieved by elucidating the intricate interplay between evanescent wave conversion and factors including refractive index, thickness, and surroundings of HHMS. Using the finite-difference time-domain (FDTD) method, influences of various HHMS properties on the conversion and transmission process are analyzed in detail. To fully harness the potential of HHMS in super-resolution imaging, the immersion conditions are elucidated.