High resolution for confocal fluorescence microscopy via extending zero-region of super-oscillation

Superoscillation is the phenomenon that is observed when a wave oscillates locally faster than its highest Fourier component. Although previous reports have been shown that the superoscillation is highly attractive for imaging, however, the small zero-region area of the superoscillation increases the remarkable effect of the outsidelobes. In this work, we introduce a method using a binary phase mask with radial polarization to extend the zero-region of the superoscillation for high numerical aperture objectives. We successfully design a binary phase mask combining with a radial polarization to obtain a big zero-region of the superoscillation. Evaluation methods rely on point spread function and simulation images are presented. The results demonstrate that our proposed method is very effective for suppressing the outsidelobes. In addition, we show that our technique becomes more effective by adding an amplitude mask. © 2019, Springer Science+Business Media, LLC, part of Springer Nature.