Correcting Structured Illumination Aberration Effects in Structured Illumination Microscopy

Abstract

The resolution of an optical microscope is limited to roughly 250 nm for biological imaging. This is due to the wave nature of light which causes an optical system to be diffraction limited according to the wavelength of light involved and the numerical aperture of the system. In order to image finer structural details of biological samples it is necessary to image beyond the diffraction limit. There are several methods for doing this. One method for imaging beyond the diffraction limit is structured illumination microscopy (SIM), a type of fluorescence microscopy where high frequency information is put into low frequency space by using a periodic illumination pattern at different phases. One of the difficulties with this method is that experimentally the periodic illumination pattern will never be ideal since it will suffer from the aberration effects of the system. This thesis presents a computer program with an algorithm to correct for the aberration effects in the periodic illumination which corrects independent of any specific type of aberration introduced into the structured illumination. The computer program first simulates one dimensional linear SIM, adds in aberration effects, and then corrects the image. The results show that the algorithm improves the superresolution image for the conditions of 0.5 wave, 1 wave, and 2 wave aberration effects in the structured illumination. With this computer program as a foundation, future work could expand the program to include two-dimensional nonlinear SIM for experimental applications.