Estimation of 3D point spread function of a widefield microscope by stochastic least square minimization method

Abstract

The point-spread function (PSF) plays a fundamental role in deciding the resolution of an optical microscope. One way to find the experimental PSF is to image sub-resolution nanobead. However, the PSF can also be approximated numerically by knowing the optical arrangement of the imaging system. In this paper, we estimate the experimental three-dimensional PSF of a widefield microscope by taking several z-stacks of an arbitrary target, followed by application of our 2D PSF estimation scheme to each z slice. Here we use a standard resolution test target as the arbitrary target whose geometrical-optics predicted image can be easily constructed.