Super-Resolution Imaging of Liquid Superlens Formed With a Transparent Micro-Concave Film

We present a liquid superlens that uses a transparent micro-concave film to confine the immersion liquids to the sample surface. This design not only prevents the immersion liquids from contaminating the objective lens but also enhances the lateral resolution of the optical microscope beyond Abbe’s diffraction limit. The liquid superlens can resolve two nanopatterns separated by a gap of about 110 nm, using an objective lens with a numerical aperture of 0.9. Further resolution analysis shows that the liquid superlens imaging system achieves a lateral resolution of
$0.25\lambda $
. Numerical simulation reveals that the liquid superlens expands the frequency bandwidth that can be captured by the objective lens by converting evanescent waves to propagating waves, thus enabling super-resolution imaging by the liquid superlens imaging system.