Super-resolution optical microscopic imaging method based on annular illumination with high numerical aperture

Abstract

On the basis of narrow-band filtered annular light-cone illumination with high numerical aperture, a new far-field super-resolution optical microscopic imaging method is proposed, and its physical model is established. Using the scalar diffraction theory, the formula of diffraction intensity in the image plane is derived for annular light-cone illumination and imaging under different numerical apertures. The diffraction patterns are further simulated through the Matlab program, which demonstrates that such a method may significantly increase the microscopic imaging resolution. Experiments have been carried out on a self-build microscopic system, showing that a resolution can be achieved to be better than 150 nm under 450 nm light wavelength and 1.125-1.25 annular numerical apertures. The experimental results are in good agreement with the theoretical predictions, thus proving the feasibility of this microscopic imaging method.