Super-resolution by annular pupil inserted scattered light fluorescence microscopes

Scattered light fluorescence (SLF) microscopy has been developed to take images through scattering media with subwavelength resolution. Here, we investigate the effect of an annular pupil on SLF microscopes via theory and simulations. As opposite to subwavelength resolution achieved by the conventional SLF microscopes, super-resolution can be achieved by annular pupil inserted scattered light fluorescence (API-SLF) microscopes. In fact, the resolution of an API-SLF microscope is usually relevant to one of its component, the scattering medium. By showing the average resolution of API-SLF microscopes that composed of different scattering media is about 0.4 times of the incident wavelength, we demonstrate that an API-SLF microscope with appropriate scattering medium is able to beat the diffraction limit.