Dark-field super-oscillatory microscopy with high-pass super-oscillatory filters

Super-resolution imaging of transparent objects is particularly challenging due to the interference caused by background light. This interference can significantly degrade image quality by reducing contrast and obscuring fine details. In this work, high-pass super-oscillatory masks are designed to address this issue by filtering out the background light on the Fourier plane. The resolution of the corresponding super-oscillatory point-spread function is 0.66 times the diffraction limit, enabling the resolution of transparent objects with 67% transparency at sub-wavelength scales. Additionally, the high-pass super-oscillatory masks are designed for a 1080 × 1920 liquid-crystal spatial light modulator, making future experimental implementation straightforward. This facilitates easy switching between bright-field and dark-field super-oscillatory microscopy, broadening the range of application scenarios for the system. • High-Pass SO Masks for Dark-Field Microscopy: Developed high-pass super-oscillatory (SO) masks for dark-field SO microscopy, enabling sub-wavelength resolution imaging of transparent objects by filtering out background light interference. • Designed two high-pass SO masks: a theoretical model achieving 0.66 times the diffraction limit with large sidelobes of 40 dB, and a practical model with 0.8 times the diffraction limit and reduced sidelobes of 16 dB, both achieving sub-wavelength imaging. • Experimental Feasibility: The high-pass SO masks are tailored for a 1080 × 1920 liquid-crystal spatial light modulator, allowing straightforward experimental implementation and easy switching between bright-field and dark-field SO microscopy, expanding its application scenarios.